My 85 4runner is on it's 2nd 22re with ~140k miles on it since it was rebuilt 15 years ago. Leaks externally and consums oil, runs rich, smokes a little on startup, gets 17mpg average on almost stock tires and has low compression (dry test from cyl#1-4: 152,142,131,105psi. wet test: 162,155,160,108psi).

It sounds like some combination of bad head gasket, valves not sealing, maybe a broken piston ring on cyl#4.

Other info: my uncle decked the head 40k miles ago when cyl head warped. He used whatever gasket Napa sells. I've read OEM is more reliable. Could this just be a bad headgasket?

For now, is it safe to run sae 40 oil? Sounds crazy, but it's already running sae 30, which made low compression cylinder 4 fire again and smoothed out the idle. Uses less oil also. It now makes a loud chattering noise occasionally, which it hasn't done since before my uncle replaced the head gasket. I'm planning to run it this way for ~1000 miles until I can fix or replace. Is this the worst idea ever and should I just let it sit until then? Thanks for the advice.

 

Sounds like your engine needs some TLC.

Your rattle may indicate timing chain/guide issues that can put coolant into the oil, watch for it.

40 weight should be fine, especially in warm weather.

 

Yeah, it definitely needs some TLC! The lady's like "how can the engine not be ok, you tune it up all the time!" Well yeah, but it's really old and who knows how it was rebuilt and treated...we bought someone else's problems.

I've adjusted the valves a couple times and keep a close eye on those guides. The timing sets not very old, but plastic rails cuz I didn't know better. Metal next time. The chain seemed kinda loose but I guess that's normal when the engine isn't running, correct? I have no clue why it's chattering so loud. It usually starts on a hard pull, like steep hills and then on/off for the rest of the drive.

Thanks for the quick reply, millball. I'll jump into this thing as soon as time and money allows.

 

For anyone reading this thread, don't hide your problems with heavier oil! In my experience, it was a terrible idea. Heavier oil increases strain on an already damaged engine. I don't think it caused any new problems, but I only ran it for a few hundred miles before tearing it apart.

Here's my rebuild thread to show several major engine problems that an oil change/any additive wasn't gonna help:
https://www.yotatech.com/forums/f115/22re-rebuild-thread-295743/

 

At times we all do what we need to do.

A used engine is beyond budget means rebuilding is out of the experience range for some.

Then I use 20/50 in all my 22R series engines the ones that are over 200,000 and the virgin fresh motors

Just how do you figure a heavier weight oil puts more strain on the engine maybe in sub zero starting .??

 

Owner's manual ok's 20w50 if the weather's warm. What I'm pointing out is I got maybe an extra 100 miles from going way heavier. Is that 100 miles (which sounded like poo at that point) really worth $20 of oil, a filter and the hours on the net reading all this junk before major engine repair is needed? If you said "yes", I ask you to check out my build thread. I had no idea what I was getting into and I'm no more capable than anyone else. I'm an amateur bicycle mechanic at best.

I know most yota owner's aren't rich and my rebuild sure as $#!t ain't cheap, but the reality is that I had a truck that was ready to quit. I'm just trying to cover my bases so other newbies don't read this in the future, copy it thinking it'll help them and then feel like yotatech's at fault.

A plain old tired engine can benefit from a little heavier oil and will run happier for awhile, tons of threads here to back that up. I agree with that. But unless you're experienced enough to know the difference, don't assume that a damaged engine is just a little worn out. That was my really expensive newbie mistake!