2.7 4cyl compression problems

[tobers]

1997 2.7 is running and driving, but it runs rough. After doing the tune up stuff, we just did a compression test (wet):

cyl 4 125
cyl 3 150
cyl 2 200
cyl 1 200

what should we do, or test, next?

thanks for advice. Rick

 

[Scramble]

1997 2.7 is running and driving, but it runs rough. After doing the tune up stuff, we just did a compression test (wet):

cyl 4 125
cyl 3 150
cyl 2 200
cyl 1 200

what should we do, or test, next?

thanks for advice. Rick

You should ask this question in the 3RZ thread. A bunch of guys are sub'd to it & should be able to assist you. My guess would be a burnt exhaust valve but I'm no engine mechanic. It's a common problem when the stock iron exhaust manifold cracks. Most people switch to a SS OEM manifold or aftermarket headers. I think compression should be 175.
http://www.toyota-4runner.org/3rd-gen-t4rs/202473-3rz-runners-only.html

 

[Kanoe]

Scramble is right. There is a lot to read about the 3rz and exhaust valve clearances. They need to be checked and adjusted on this engine.

If you don't know that yours have been checked that would be a good place to start. It's a relatively painless days work to check them. Adjusting is another matter..

Google 3rz valve clearance also.

 

[tobers]

thanks. I know it had a valve job about two years ago, and they were adjusted then, maybe 15k ago. But we can check them.

what concerns us is that the dry compression numbers were

cylinder 4: 90
cylinder 3: 90
cylinder 2: 115
cylinder 1: 115

and wet they were much higher, which made us not suspect the valves. I'll try to check them tomorrow.

Also wondering about two side by side cylinders ... maybe head gasket. Basically just trying to diagnose properly. thanks for help

 

[snow junky]

I would say you have a head gasket problem. I would have valves checked when heads pulled.


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