My 87 4Runnah with a 22RE is back on the road again after taking a 14 year nap. I had to deal with a few oil leaks but now she is leak free. The only problem is that I'm burning through about 1.5qts per 3000 miles.

It runs perfect and runs great. It has a new PCV valve and I gave her a tune up. Any common areas that cause excessive oil burn? Or is 1.5qts about normal for a 25+ year old engine.

The 4Runner has 90k on it but the motor that is in it was replaced about 15 years ago with one out of an 85 that has about 125k on it now.

So how much oil do you burn?

 

Could be dried out valve seals. Any smoke at startup or normal driving?

 

Sorry should have mentioned that. No smoke....ever. Tailpipe is a little sooty but nothing crazy. In the summer I run 15W-40 just in case someone is wondering if I put 0W-20 in by accident or something.

 

Any coolant oil mixing anywhere? That's really not a whole lot over a period of time. My DD uses about .5qts in 15k miles. Have you done a compression test? Leak down test?

 

No coolant in oil or oil in coolant. I may do a compression test and take a look at the plugs this weekend. I was hoping there was something simple that causes these motors to burn oil that I overlooked. They are so full of emission gadgetry and vacuum lines I wouldn't be surprised.

 

I have had a few 22re's over the years and all of them burn some oil. Even my supped up 22re burns some oil. Doesn't bother me any, I know the oil is going to where it needs to go.

I also run a thin oil, Mobil 1 5W30, which is on the thin side of 5W30's. I run it because of the tensioner on the timing chain. So some burn off is normal.

It's when the engine starts to make oil is when you need to be concerned. That is a dead give away that a fuel injector is leaking.

 

Interesting. I thought a thicker oil would improve oil pressure....thus helping the tensioner. I'd like to hear your reasoning as why a thinner oil would be better.

I run the 15W-40 mainly because it is a diesel oil and has more detergents and a higher zinc and phosphorus content than what is allowed in most -30W SL-SN oils.

 

Generally, if you're "needing" to run a thicker oil, it's because there's another problem that's not being addressed. I've always seen thicker oil as a bandaid for a motor that leaks or needs a rebuild. That said, as long as the pressure stays correct I don't think it hurts anything.

Go read up on the BITOG forums if you really want to second guess everything you've ever thought about oil. Consensus is to run as thin of an oil as possible without losing pressure.

 

With a thicker oil, your sacrificing flow for pressure. On the back side of the tensioner is a little orirface with a hole in it. That hole makes pressure constant, regardless of oil weight. Where the oil weight comes into place is the oil pump. The pump has to pump the oil up into that little hole. The thicker the oil, the longer it takes to reach that little hole. Thus, it takes longer to take the slack out of the chain.

Flow>Pressure.

 

As said above Bobistheoilguy is a awesome place for any oil discussion and what not

 

Thanks guys. I'll give a lighter oil a shot next change. I did a compression test and was surprised by how good things were. The plugs only had about 2,500 miles on them and looked great. The compression was 172, 168, 165, and 161. Not bad since Toyota specs 171 as stock and minimum as 142.