I drive a Subaru Liberty 2005, which recently hit 200,000 KM. Usually I use 5w30 engine oil. But For few months now the sound from the engine has gone up (which is annoying). I have also head that when you hit 200K or more with your car, we should use a bit thicker oil for better protection. I would like all your valueable advice.
BTW I dont have the owner's manual.
Thank you in advance :)
Whats the different between 5w30, 5w40, and 10w40..?
You may have Wiki'd the answer, but my basic understanding is this.
The numbers relate to the viscosity of the oil at cold (the lower number) and operating temperature (the higher number). The oil must be less viscous (thinner) on cold startup to enable the oil pump to get it quickly up to where protection is needed.
After the engine has warmed up, in the normal operating temperature range, the oil now has to protect in different circumstances. Stop-start, higher rpms and a hotter environment. This is where the second number comes in, and mainly refers to shear protection (resistance to the oil film separating and exposing metal to heat and wear).
Whats the different between 5w30, 5w40, and 10w40..?
The 5's will flow easier on cold start than the 10. In a high km car, I'd use 40wt to account for the greater tolerances (gaps) between components at higher temps.
I'd advise you to download a manual for your car at least. And further, don't deviate too far from the recommended viscosity or certification. The latter probably won't be an issue in a car of this age, as newer grades often supersede older ones.
I am no mechanic and own a MY01 liberty with 260kms on the clock. I would think engines are designed to use a specific oil for a reason. If its too thick, it may kill the oil pump and may not make its way around all the cavaties it needs to flow through?
I use the standard 5-30w oil but always change it every 6 months and use a fully synthetic.
Do you know of many failures in oil pumps or is that just a guess?
The reason to go thicker is that the engine wears so the engine at 260k is not the same as the engine after 20k. Thus specified oils when new are not always best when old. Using a thicker oil is quite commonly done. I wouldn't do it unless there is a problem, but if you can hear metal bits slapping around (normally a clatter that is a sign of wear) then that is an issue in itself. Using a slightly thicker quality oil is widely recommended and will slow down further wear. The real solution is an engine rebuild, maybe just the heads if compression is fine. Using a thicker oil slows the degradation down. After 200+k you are really just nursing the engine until its death, hopefully get another 100k out of it. Using a thicker oil will extend that time in many cases.
Going up to a HPR 10 from HPR 5 is, in my opinion, unlikely to damage your engine, but is likely to extend its life.
If it's not burning oil then why bump up the viscosity?
the channels that the oil flows in, bearing journals etc, wear and get larger with time. The gaps between them therefore grow, causing a pressure loss and clattering sound in the valve train. Usin a thicker oil increases pressure where the oil is needed, reducing the noise and wear.
What 5w30 oil do you guys prefer to use?
Any good brand, fully synthetic oil should do, mobil1, castrol titanium edge, royal purple, etc.
One mechanic advised me to use 10w30, where another one said to reduce engine sound and wear I can use 0w/5w/10w40… Thats what made me more confused.
My suggestion is to use penrite. I have found it to be good for worn engines as it seems to be good at quietening them down. My take on it is a quieter engine is having less parts rattle against each other and that is a good thing. If it was a new engine then there are a few choices as mentioned but to me Penrite hpr10 would be the go. It is a quality fully synthetic oil.
Just a thought… I have a 97 honda civic, used many different oils over my time but still find the best is what was originally recommended (for me it's 10/40) however after hitting 200,000 i too noticed engine noise and got the tappetts redone (reset) and made a big difference, so might be worth also looking into especially if the noise is very "ticky"
I've a Subaru Impreza MY01 - sadly not the WRX version :(
It's done just shy of 300k - I've always used synthetic oils (recommended viscosity) with both oil and filter change generally every 5k - no point leaving dirty oil to mix with the fresh oil.
Whilst the engine seems as good as it did at 100k, my mechanic has said the car has passed its use by date and I need to look at changing before something that costs a lot happens at an inconvenient time.
You will probably get to 400k klms before that. I have seen a couple of earlier models with 450 and nearly 500k klms back in the day. They were the GC8 but essentially the same engine
Having said that I would bump up a thickness to quiet down the lifters as doing them is pretty much an engine out job, and while someone who is used to pulling Subaru engines can have one roll in and engine out within 90 mins, they will still charge $400 to remove PLUS setting tappets
Just keep the servicing up and when it starts to burn more then 1L of oil per oil change, you can just change it with a wrecker motor which should be $1200 at most.
Google proma oil
Can you please tell me which particular product?
You want the one with the proven independently verified results. Oh, wait, that is none of them.
Results from a test engine are not the same as results in real world. That is my experience as an engineer.
This has all the hallmarks of snake oil.
Just buy good oil, any type, change it as recommended or a little more frequently, and if you have a problem with noisy engine either:
1. get it fixed
2. try a slightly thicker oil to see if that helps.
thanks I will try thicker oil..
I run penrite hpr 5 (5w40) in my Subaru. It is a little thicker and I find penrite gives better pressure in old engines. If that is not doing it try a 10w50 HPR10.
it is not cheap oil, but I buy it when on special to save a little.
In my opinion the slightly thicker oil will not be an issue in an older engine, but you might want to check with your mechanic. My mechanic agreed that thicker oil was good for my wife's old 4wd with 200k+ on the clock which was clattering on startup and burning a little as well.