[AMA] I'm a Mechanic. Ask Me Anything

AMAs seem to be the cool thing to do lately, so thought I'd give it a try. Have been a mechanic for 15 odd years, worked on everything from Hyundai to Porsche. Recently moved to marine in the last year or so. Will try to answer when I can.

Edit - Wow this was much more popular than anticipated, thanks for the great response everyone, hopefully it's helped a few people out.

closed Comments

  • jump starting a car

    what's the correct sequence? I hear you don't connect negative cable to the dead battery but a bare/unpainted metal under the bonnet.

    • in this day and age, it's probably better just to buy a portable jump starter and keep it in the boot. For less than $100 it's a good investment.

    • The cable that goes from the negative terminal of your battery is effectively a ground strap. If you follow it you'll probably find that it eventually connects to a bolt on your chassis somewhere.

      If that ground connection is good then connecting the jumper lead to your battery isn't going to damage anything in the car's electronics as it is performing the same function as it does when your battery is working normally.

      Generally when you connect a jumper lead you go positive terminal on donor battery to positive terminal on flat battery, then negative terminal on donor battery to chassis grounding point on flat battery car.

      The logic behind this is that when you make the final connection with the jumper leads you often get a spark. As regular batteries vent hydrogen gas when they charge, there's a chance that a spark could ignite that gas, so making the final connection away from the battery is deemed to be safer.

      On modern cars it can be challenging to find a good chassis grounding point due to the aesthetics of the engine bay, so the only option is to ground at the battery terminal.

    • You can connect it straight to the battery. The only reason for not doing it was possibly creating a spark, but most batteries nowadays are sealed. Perfectly fine to connect to a piece of metal though, ground only obviously

  • Hi brendanm,

    Thanks very much for this AMA!

    I’m looking to buy a 2011 honda Jazz VTi Auto (65,000 km). Seller offers $8000 and the test drive yesterday seemed alright to me.

    My only concern is that the car was last serviced in mid 2017 (~48,000 km). Seller said she would bring the car for service before selling.

    Your thoughts and advice?

    Cheers

    • $8000 for a 2011 Jazz is way too steep… I wouldn't buy it simply because it's overpriced IMO.

      I'd bring a mechanic with me to inspect the car. If there's problems you need to fix, it's likely a lot more than what you pay to hire a mechanic for inspection.

    • I'm no expert but if the seller hasn't serviced it in nearly 2 years and/or 17K which is somewhat neglectful, it's not the type of seller I would like to buy from. And as above 8K is too expensive. I'd consider with the poor service history if it was around the 5-6k mark.

    • What both of these guys said. There is no shortage of jazz's available, buy one that has been looked after.

  • Hi Brendan,

    Thank you for being so helpful! This thread has taken off!!

    I just had a question about a DTC that comes up once in a while when driving at 100+ km/h on the freeway for about 1-2 hours: P0089 Fuel Pressure Regulator 1 Performance comes up randomly once in a while. I end up clearing the code, and it is fine otherwise while driving or putting the foot on the accelerator. It seems to only stall when braking or letting the foot off the accelerator.

    The car is an Epica Diesel and this has been happening for the past 3 years at least with the random P0089 coming up while driving. When this issue first started, the engine would stall and shut off when braking to come to a stop at a red light or slowing down to say 5-10 km/hr. This stalling has stopped happening lately though except when driving at freeway speeds.

    I've tried diesel injector cleaner and changed the fuel filter but this randomly still happens once in a while. Another bit of information that might help is that I used to have a habit of running my fuel tank to nearly empty for a while, but I haven't been doing this anymore. Maybe a fuel pump that has gone slightly bad from this bad habit of mine.

    Have you ever come across this or have any thoughts or suggestions?

    Thank you!

    • +1

      Your theory about it being a mechanical issue with the fuel pump / pressure regulator seems about right.

      Not sure how the fuel lines are set up on the Epica but the fuel pressure regulator either sits on the fuel rail itself in the engine bay (when there's a return line to the fuel tank) or it sits near the fuel pump on cars which don't have a return line.

      If it was my car I'd be investigating the cause as the car cutting out at freeway speeds sounds dangerous.

      • Thanks, your comment makes me want to have a closer look to make sure that this is sorted out sooner rather than later

    • Generally this is caused from a failing pressure relief valve in the end of the common rail. Sometimes you can find just the valve for sale other times you have to buy the entire rail. Stalling issue can also be caused by suction control valve on the high pressure fuel pump.

      • Thanks Brendan, I will see if these fix the problem

        Thanks for you help!!

        • Don't just throw parts at it, if you have an obd scanner you should be able to watch your rail pressure, or if you aren't that way inclined, your mechanic should be able to, to see if rail pressure drops suddenly at any point.

          • @brendanm: Thanks Brendan,
            I was just about to order parts, good thing you stopped me!

            I remember when scanning and monitoring the fuel pressure when the problem first started 2 years ago, at idle it would have a few spikes in pressure every 2 seconds and that was when the problem was at its worst with cutting out when stopping at nearly every red light.

            Over time I tried a few things like putting injector cleaner in the fuel tank in moderation, looking at the wiring, etc. and it's calmed this problem down alot and the P0089 code only now comes up when driving on the freeway at 100+ but not stalling. Only when slowing down and rolling to a stop after driving for 3-4 hours on the freeway at 100+ km/hr is when the stalling happens now. Maybe it's the heat affecting the pressure regulator because of engine being super hot from freeway speeds + length of driving?

            I just had a look now at how the fuel pressure graphs are at idle and driving in surburbia and it looks very well behaved and pressures as expected: increased pressure when accelerating, decreased pressure when slowing down, etc. no random spikes in fuel pressure any more

            Do you think that it might be dirty injectors or dirty pressure regulator that's slowly unclogged as it's gotten better over time?

            Also do you find that these injector cleaners, engine oil additives, stop leaks, etc. even work? or are they snake oil?

            Thanks for your time as well Brendan, I would totally shout you a beer if I were to meet you!

            • @trevs: The pressure relief on the end of the rail isnt actually a regulator, it's simply a safety over pressure relief valve. The thing that controls the pressure is the suction control valve, which is on your high pressure pump, it's normally the one that gets sticky and causes the idle cutting out issue you had. I would normally class injector cleaners as snake oil, but as our diesel is now so low in lubricants, it may have been enough to "unstick" your scv.

              The pressure relief if a different issue. These can relieve pressure too early or at random times if the spring is weak. It is only meant to relieve pressure when it gets to a "dangerous" level in the rail.

              • @brendanm: Thanks for explaining Brendan, I think I'm slowly starting to understand it now

                Just now I opened the engine cover and everything looks fine with the fuel lines and return lines. I see the suction control valve on the high pressure pump and the pressure relief valve on the end of the rail you're talking about

                Would it be possible to take the SCV and pressure relief valve off and clean them out by wiping and flushing with injector cleaner? Or would just I end up ruining them ?

                They seem to be a bit tucked away and I can already imagine the swear words coming out of my mouth when trying to take to them off

                • @trevs: Yes you can definately clean the scv, just don't let any dirt at all get in the hole. What sort of setup is the relief valve? Can you post a picture of it?

                  • @brendanm: Hi Brendan,

                    I took some photos last night and realised that I had mistakenly thought I saw the relief valve on the fuel rail in the morning, but it is actually the fuel pressure sensor according to the service manual. It's very strange as I can't find where the relief valve is (service manual calls it fuel pressure regulator). The service manual says that it's on the opposite side of the fuel rail to the fuel pressure sensor, mine is just a bolt which is very strange.

                    https://ibb.co/TRdcDt5

                    Have I been driving around without one for the last 60,000km and managed to get by? I bought this car second hand and wouldn't be surprised if something dodgy like this has happened, the dealer wasn't very trustworthy but I find it hard to believe that the car would still drive that many Ks without one

                    The service manual says that the return system works by "The fuel return system routes fuel from the fuel injectors, fuel rail, and the fuel injection pump. The fuel pressure regulator is located in the common rail. The return fuel travels to the fuel tank. If the high side fuel pressure becomes excessive, the fuel pressure regulator releases the fuel into the fuel return system."

                    Pictures that I took are below of the high pressure fuel pump, scv, fuel rail and the end of the rail missing where the pressure relief valve is supposed to be

                    High pressure fuel pump: https://ibb.co/RgxgzNZ
                    Fuel rail and injectors: https://ibb.co/N7LtF43
                    Right side of fuel rail, missing pressure relief valve: https://ibb.co/kBckV20
                    Engine bay picture: https://ibb.co/wsJkYvD
                    Fuel pipes diagram without pressure relief valve: https://ibb.co/yhwQdPk
                    Fuel pipes diagram with pressure relief valve: https://ibb.co/qgtx1V3
                    Exploded diagram fuel system (note the pressure valve on the right side of fuel rail): https://ibb.co/6yL21xB
                    Diagram of pressure relief valve: https://ibb.co/vDTPkwh

                    The service manual is for the 2008 model, but mine is a 2010 car. They might have changed the setup between years maybe.

                    This is all very confusing

                    • @trevs: That's interesting, do you have a small diameter hose coming off the rail near the pressure sensor?

                      • @brendanm: Hey Brendan, sorry for the late reply, I just had a chance to take it apart again and have a closer look
                        The fuel rail just consists of the sensor on the left, and the 4 pipes from the fuel rail to the 4 injectors and one pipe from the high pressure pump to the fuel rail. No small diameter hose coming off the rail near the pressure sensor and no pressure regulator valve(pressure relief valve)

                        I'm guessing the pressure is controlled 100% by the SCV on the high pressure fuel pump on my version of the car.

                        Do you think I should just try and source the SCV that goes on the high pressure pump and see if it fixes the problem or take it off and try and clean it out?

                        • @trevs: Pressure is always controlled by the scv, the pressure relief is just a safety incase something goes wrong, stops the rail from turning into a grenade. Perhaps the pressure relief is in the pump?

                          I'd give it a clean first, nothing to lose that way.

                          • @brendanm: Thanks Brendan, you're right the pressure relief must be somewhere in that fuel circuit, I just had a chance to take it apart and give it a clean, I will see how it goes now on the freeway !

                            Thanks again for your expertise !!

                            • @trevs: Good luck mate, hope it works out for you!

                              • @brendanm: Thanks mate ! We need more honest mechanics like yourself out there, you've been very helpful thank you!! :)

  • Hi Brendan,

    I am looking at a 7 seater SUV and has listed the following options:
    - KIA Sorrento
    - Mitsubishi Outlander
    - Honda CRV
    - Hyundai Santafe
    - Mazda CX-8 or CX-9
    - Nissan X-Trail
    - Toyota Prius V

    My main criteria is:
    - Fuel economy - no engines more than 2.5L
    - Good price and reliable (which is why I have chosen all Japanese or Korean brands)
    - Reasonable yearly running cost

    The car itself is used for A-B city driving.

    Questions for you:
    - Any other make/model I should be considering?
    - Any recommendations on what to avoid from the list or what I should go for?

    Thanks

    • Some of those a 7 seaters, some are 5+2. Engine size doesn't necessarily correlate to fuel economy, a small engine constantly working very hard will generally use more fuel than a large one loping along.

      The xtrail is still using the qr25 engine that was underwhelming when they introduced it in 2002 or so. Apart from that they would all be fine, would depend mainly on which was the size, layout, and drive you wanted.

  • whats your greatest DIY failure from a customer you've had to reverse

    • Anytime they have pulled something apart, lost half the parts, and then say "labour should be cheaper as I've already pulled it apart from you" hahaha!

      Had a guy change the front brake pads in his car, he bought it in because it was making a clunk everytime he brakes in reverse. He had left one of the caliper bolts out, so it would flip up and hit the wheel when braking in reverse. Pretty scary.

  • +1

    I think a Service to the Ozbargain Community Award should be forthcoming to brendanm.

  • Hi Brendan, thank you for an excellent AMA.
    I have a 06 Honda Civic, still driving well. Only issue is that there's a tiny squeal sort of sound coming from the brake assembly every time brake pedal is depressed. Before this started the noise used to come after I let my foot off the brake. I have tried to lubricate the parts in brake pedal assembly but that doesn't seem to help.
    I have yet to bring this to a mechanic for a check, I hope you can shed some insight into this, hopefully it's not something major.
    Thank you.

    • Do you mean the noise is coming from near the brake pedal itself? Or the brakes?

      • Yes it's near the brake pedal, the brakes are fine.

        • You will likely need to grease or replace the bush that the brake pedal rides in in the pedal assembly, it's likely dry. You could possibly get it by spraying wd40 or a silicone spray around the general area liberally.

  • Got a 2nd car (LC200 diesel) that I don't drive much, never get required mileage (10,000km) before the due date of the service (6 months). Is it ok to wait until 10000km (could be in 1-1.5 years) or should I be doing it as Toyota wants me to do? (car is out of warranty). Thank you!

    • +1

      I would be doing it yearly, and check the oil often, they have a habit of drinking oil and destroying engines, my engine builder does a tonne of them.

      • Thank you so much!

  • Hello.. How about power steering fluid change for German cars. My mechanic told me not to worry about it but the car is over ten years old and has done 120k kms

    • How does the fluid look? If dark, replace, it's easy enough to do, and pretty cheap.

  • VW Jetta 2012 TSI Highline
    Issue - when going over bumps or when the wheel rises from the arch itself there is a cracking/knocking noise coming from the front right hand side. Not when hitting the bump but when the suspension rises you hear the noise. Any idea what that could be?

    • +1

      Damaged strut mount or strut bearing would be my guess.

      If you can enlist a helper to bounce that corner of the car while you look at the suspension from underneath and in the engine bay where you can see the top of the strut, you might be able to see if anything is moving abnormally when compared with the other side that doesn't make a noise.

      • +1

        This. Sounds like the strut top, but being a Jetta, could also be the lower control arm rear bush, if it's never been done, it's likely almost stuffed.

        • What I find strange is there are no symptoms of having a bad strut mount or bush. Car does not bounce when hitting bumps and at high speeds the wheels do not shake. Car does slightly veer to the left but that could be wheel alignment.

          • +1

            @sirlitchfield: Bouncing is a symptom of a bad strut, not a mount or bush. Wheel shaking is a symptom of wheel balance, or a wheel/tyre out of round. If the control arm bushes are gone the alignment will be way out.

            • @brendanm: Thanks for your input on this. I guess the next step would be to bring it to a qualified mechanic, pass on the info you gave and have them check it out. Thanks again.

              • @sirlitchfield: Yep that would be best, if they've had any experience at all with vw they would know about the control arm bushes.

                • @brendanm: I'm due to get it looked at by a mechanic this Friday, will see what they say.
                  A separate issue with this bloody car, oil consumption. Just got the check oil light coming up on the dash and I just topped this thing up to full around 2 months ago and now its at the min level. A lot of stop start driving and only traveled around 1500ks in that time. A lot of forums say its normal for turbo vw's to consume a lot but that seems a bit excessive to me.
                  I should note that not long ago I got an error code P0441 come up for about a day and then went away on its own. Not sure if related.

                  • @sirlitchfield: P0441 can come up from a lot of things, can be as simple as not having the fuel tank cap on tight.

                    The oil consumption is "normal" according to vw. It's a byproduct of extremely light piston rings. I think I've mentioned it elsewhere in here, but my engine rebuilder fixes them by putting in proper rings, and coating the pistons. It's an engine rebuild though, so it's obviously not cheap.

      • If it is the rear control arm bushes (console bush) note that VW only sell the bush already fitted to the housing.

        Febi partno 33973 is just the bush. It's an Audi S3 part and will make the steering slightly less "doughy". <$100 pair

  • Tyres..
    Looking for recommendations for a mid to high range tyre for a fairly standard jap/kor hatchback, e.g. 205/55/R16
    Any specific brand and model?
    Quiet road noise and fuel efficiency would be a priority.

    Great AMA, Cheers

    • I've used http://www.tyrereviews.co.uk to choose the last 2 sets for my car. I also leave feedback there based on my experience. I would like to know if there are more good sites like that to search for reviews and tyres quality to make a good choice. Brendan/ Namadesque, are there any websites you know to find reviews about tyres?

    • Michelin Primacy 4

      Continental Premium Contact (whatever the latest number is)

      stay away from Toyo Proxes C100+. They don't like wet weather.

  • I want to learn to do more advanced car maintenance my self (not for a career change but as a hobby). At the moment, I've basically just been trying my self, watching youtube videos, reading forums and trying to do download service manuals. Do you have any recommendations on where I can learn?
    I was seriously considering doing a pre-apprenticeship but now I have a baby on the way I doubt I have the time to commit to something that rigid.
    I want to do more advanced things like change brakes, control arms etc.

    • The Workshop manual is normally good enough to guide you through the way. You slowly learn tips/tricks as you go along while checking youtube. Some local forums might have a tech day where everyone gets together to fix each other cars. Joining a car club might be a good way as well. I would recommend Eric the car guy on youtube, he's very informative.

    • In addition to darkage's comments, if you have enough room where you live you can look to buy a reasonably complete wreck of your daily driver car to play around with. You then don't have to worry about making a mistake on the car you rely on the first time you attempt a job.

      When it comes to jobs like replacing control arms you may need to purchase additional tools such as tie rod end / ball joint separators which make the job a lot easier.

    • From memory there are sometimes car maintenance courses rum by tafe, not sure if they still do them? Apart from that, it's literally just doing it. Factory service manuals are great if you can get them for your car, will generally give you a pretty thorough run down on everything.

      Congrats on the baby!

      • I'm sure you'd agree but sometimes factory service manuals can be over the top. According to my fs manual half the car had to be dismantled to change the shark fin antenna. I just popped 3 clips pulled the liner down a few inches shoved my hand in with a socket (without the wrench) and changed it over in 10mins.

        • +1

          They sure can be, also insist on special tools for basically every single job that can be accomplished with a screwdriver and adjustable spanner. However if you have one, you can almost certainly complete whatever job it is you have to do.

          I suppose in your examples if they tell techs to do that, and the customer then has a crease in the liner, they will be very upset. You can get away with a lot more things in your own car.

  • Why does my dealership always overfill the oil :P (BYO oil btw) I only ever taken my car there twice only since car was still in warranty period, 2 times I've had to syringe out excess. I can definitely feel & hear the difference when it is overfilled. I just changed my oil 2 weeks ago myself, and to my surprise I was spot on with my guesstimate without next day topups.

    • Mainly because they don't care I'd say. It takes an extra couple of minutes to make sure it's right, and most people will never check.

  • What should a timing chain replacement cost on a VE commodore?
    Thanks in advance

    • +1

      Between $1500-2000 using full genuine kit, with coolant and oil and filter changed.

  • Apologies if this has been asked. You've done really well in this AMA!

    How often do clients/customers buy a car part from overseas, and ask you to install it? I've heard of people flying to Japan to buy parts and bring them home as check in luggage to save money. That and re-sale of parts direct from the factory.

    • People would sometimes buy bits from eBay, very frustrating as often it would be incorrect. They also have no warranty on the part, so can come back to bite them if the part fails and they have to pay for labour, and the part, again.

  • Have noted that the transmission oil in my car is quite dirty and tossing up between a oil change or flush. Information out there seems quite varied - is it much of a muchness between either of which I choose? And so I should just opt for the oil change which is cheaper?

    Also, any idea on what a maximum reasonable amount to pay for a oil change/flush would be?

    • If it looks dirty I'd flush it. Hard to say without knowing the car, but a normal thing should be about $130 or so, at least double for a flush. Flushing uses a lot of fluid.

  • I made it to Page 9! This is easily the most enjoyable thread on Ozbargain :-) Thank you for starting it!

    Now for my questions:
    1. Does mechanical empathy exist in your field? Can you learn it or do some people just go through their mechanic career without it?
    2. What do you enjoy most about being a car mechanic?

    • Does mechanical empathy exist in your field? Can you learn it or do some people just go through their mechanic career without it?

      Heh, I'd say that a mechanic's empathy for people's car troubles is probably highest at the start of their career and then quickly diminishes as they deal with customers who think they know better than the mechanic, complain about price, don't take advice about parts that need replacing etc. etc.

    • How do you mean mechanical empathy? A feel for not breaking things? Being easy on equipment?

      I'm not a car mechanic anymore :P However the thing I enjoyed most was fault finding, and fixing major issues. It's much more rewarding and interesting being able to make something go again that was broken down, than just changing the oil and filter.

  • Hey mate, great AMA. I blazed through all 9 pages.

    I'm in the market for fun/sporty used car for around $20k. The ones I've been paying most attention to are: Toyota 86 GTS, Nissan 370z, MK7 Golf GTi - All in 6sp manual.

    Single, no kids so practicality isn't an issue. I'm really leaning towards the 86 because of the rave reviews but I'm worried it's lacking in guts. What would you choose from the 3 and why (Servicing, Repairs etc)?

    Cheers

    • Just for on the street, or on the track?

      • Purely street. Mostly daily and maybe a weekend in the twisties every now and then.

        • I personally wouldn't get the 86 then. Out of the other two, they are vastly different cars, have you driven them both?

  • hi brendanm,

    I am trying to decide between buying a post-LCI E90 330 or a post-facelift W204 C300.

    According to your experience with both cars, in terms of reliability, which one would you recommend? I know it is always a bit risky buying a used Euro that is 8 to 9 years old, but where I am buying them, they are actually cheaper than used Japanese/Korean cars of the same vintage, and there are actually more to choose from.

    The E90 is at least 10-15% cheaper than W204, but will it cost more to keep on the road? The availability and cost of run-flat tyres could also be factors for me to consider.

    I actually like the looks of the B8 A4, but have heard horror stories about their CVT/DSG transmission, not to mention that my budget won't stretch to the Quatrro version, so it would be a FWD vs RWD E90 or W204.

    If I add a couple of grand to my budget, I can actually get an early model F30 320, but I am a bit wary of the reliability of the I4 turbo unit as opposed to the proven bulletproof N52 I6 motor.

    Thanks!

    • Based on my experience, BMW is less reliable and required more maintenance. I have had not a good experience with BMWs 2000s: leakages or engine wasn't reliable. Though I had no experience with post-2011 BMW, from what I have read here, nothing changed about BMers. I have had C280 w204, which is 3L prior to the facelift. With the facelift it became C300. I have had no problem with it. Important to mention a good previous owner. However, I like C250 twin turbo diesel W204 more than the 3L one for punch, lighter weight, torque and response. I love the look of Audi inside and out. I have had a few a while ago. IMO Audi is much more reliable than BMW. I read on the internet the post-2011 Audis are much more reliable including the gearbox. You can negotiate the Quattro S line 2011+ model with around 100k kms for around 20K. I rather go with that, than BMW. Merc w204 C250 is close to that price range as well or cheaper. Merc or Audi 2011+ models would be the choice. I would like to know the reliability of the 2011-2014 Audi S-line Quattro. They have very close power range with Merc C250, safer ride due to Quattro. Was the gearbox in Audi fixed completely? Do your horror stories include post-2011 Audi models?

    • +1

      I personally prefer driving BMW's over Mercs, but the Merc diesels are quite nice. I'd personally go the 6 cylinder over the 4 in the Berners, though I'd also get a 5 series over a 3, they can generally be had for similarish money. Reliability wise they are much if a muchness, merc probably out in front, BMW and Audi similar. If the Audi is a CVT, they put a new clutch pack with more clutches in it after approx 07 from memory, they are still not my pick, and still have issues. Dsg are much better if you get a wet clutch one.

      • Out if interest what would you think would be a reasonable amount for a mechanic to charge to do a full flush and refill of coolant for a mid 2000 5 series?

        I assume if coolant hasn't been changed for about 7 years a flush with distilled would be recommended?

        Also in terms of the cooling pipes would you only change the ones that the plastic is looking brown or do the whole lot?

        Many thanks

        • Probably around $170 or so I'd say, I didn't personally flush cars as we used the local radiator shop, as the flushing is messy and time consuming.

          I would do the whole cooling system, can be done fairly cheaply. Do things like the plastic blank off plug on the side of the block as well (I'm assuming you have a 6 cyl), they will just randomly break and blow coolant everywhere.

  • Hi mate, thanks so much for this AMA! I just took my Toyota 86 to get serviced today (not at a dealership) and was just told that the left rear wheel bearings need replacing. I was quoted $450 for the part and $150 for install. Does this sound about right? Thanks!

    • Are the bearings noisy? Price for bearing seems high buy maybe that's just the price from Toyota. It's a very easy bearing to replace as it's a hub type, so simply bolt on part. Is the labour price $150 an hour?

      • Sorry for the delayed response. It ended up being $130 total for the labour and $422 for the bearing. Unfortunately, I didn't get to ask if the part was genuine OEM from Toyota.

        Here's a picture of the invoice:
        https://i.imgur.com/3wj2u1R.jpg

  • Hi Brendan,

    Earlier I asked about 2008 Mazda 3 auto vibration in idle and checked all engine mounts which appears they are in good shape. Further careful observation engine actually vibrates in idle every time ac cycles and clutch is engaged. Rpm would normally sit around 700rpm in idle but when the clutch is engaged it drops down to 500rpm and vibrates then gets back up to 700rpm. Repeats back and forth every couple of seconds. No engine codes atm.

    What could be the issue causing idle drop to 500rpm when ac clutch is engaged?

    Thanks
    Tim

    • The a/c puts load on the engine, dropping the idle, the idle air valve (or the throttle body itself if you have the newer model), is meant to open and bring the rpm back to normal. How long does it take to go back to 700rpm? How did you check the mounts? They can look perfectly fine, but have sagged, and will vibrate with a small.bitnof engine movement, like the idle dropping a bit.

  • -1

    Duplicate

  • Hi Brendan..
    Thanks again for the AMA
    I want to know your opinion on Nissan Cube 2003 with 100kms.
    heard this car is imported from Japan, so how is the spare part? easy to find?
    and is it reliable?

    also compared with Honda Civic 2006 VTI-L with 185kms.

    Thanks!

    • Cube is fairly popular, an possibly shares some parts with local vehicles, Nissan is normally good at sharing parts between models.

      Cube and civic are fairly different cars, from memory the cube has a fair bit less power, and won't be as nice to drive as the civic. But the cube has more room if you want to put largish things in.

  • Hi Brendam,

    Have a 10 year old VW passat cc, starting show its age with rattles and creaks from the dash area.

    Most annoying one is from drivers side storage compartment , previous i tighten all visible screws in the area.

    Whats the best strategies to identify isolate rattles and possible solutions.

    • Put foam tape between bits that are vibrating, if possible. They can be very hard to find, having someone press on parts of the dash etc while driving can isolate them to certain areas.

  • Hi Brendan,

    I have a 2009 MY10 Subaru Impreza RS Sedan (Auto).

    I love the car but it chews through fuel (10-11 L/100k) for the small to medium trips I usually take it on.

    I'd be interested to know your thoughts on these cars and if you've had any issues with them?

    I've also started to have an issue where if I take it on long trips I get a few lights on the dash, after pulling the error code from the OBD II port it apparently relates to the catalytic converter. However after clearing the codes I haven't had it come up for months but it came up twice on my long trips.

    If it is the catalytic converter is it common for these to need to be replaced so early? My car only has around 88,000km.

    Thanks in advance!

    • +1

      They have always been fairly thirsty, just how they are. Is the code for cat converter or O2 sensor?

      • At least it's not just me!

        Here is what I pulled;

        Fault Code: P0420 Catalyst System Efficiency Below Threshold

        • +1

          Can be the cat converter, could also be the post cat O2 sensor. A good scan tool that can show you the waveforms of the sensors should give a better idea as to which, I'd be leaking more toward the O2 sensor personally.

  • Hi Brendan,

    Steering of Ford Territory 2005 vibrates when it goes above 80. Wheel rotation and alignment didn't make a difference.

    Also got new fuel filter and got transmission fluid service and none of them made any difference.

    What could be the reason?

    • Brakes are dragging, common fault due to the brake booster. Undo brake master cylinder and pull it forward, then screw the adjustable end on the pushrod in a few turns to shorten it. Refit master cylinder. You will quite possibly have to replace your brake rotors if you get shudder when braking, they've probably been overheated a fair few times.

  • do you think Honda HRV 2018 good ?

    • Haven't had much to do with them as I haven't done cars for a year for so now. If it's like other honda products, it's probably great.

  • What are your thoughts on the Nissan GTR R35 09 servicing and reliability wise.

    being first release there would be issues, but just wondering if you have serviced and received feedback on these models. input on services, going aftermarket parts as warranty would be expired, tuning, long term ownership.

    originally had a 99 JDM S15 years ago, was a good drive and now missing the adrenaline and looking for a newer sporty car, why not go GTR I'd say?

    I haven't owned a car since 2015(since I joined OzB, I went broke), so just been driving partner's wagon around, Compass 13'.

    There's also the idea of family orientated the Toyota Landcruiser 200 series Sahara 13-15. I know Toyotas are known for their longevity. this is just a side side option. I'm more interested in the GTR tbh.

    • 200 series td V8s are a bit of an oil burner, seen a fair few with seized engines, my engine builder has plenty of work rebuilding them.

      The GTR is a 1/ year old car that has likely been driven hard. I don't know much about the specifically, have only known owners of a couple, and they were heavily modified, and tended to break bits and pieces. Do you intend to track it? If just street driven, I can't imagine it's a good choice.

      • Just for spirited driving when I'm back on break. No track days in foreseeable future until parts break.

        200 series can those problems be prevented with catch cans and oil upgrades? Pump, temp sensors etc

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