I have no compression in one of my middle cylinders, (if facing the front of the car, it would be the left middle cylinder, second cylinder from the dizzy). funny thing is the car still has decent power, and still gets 35+ mpg. just smokes when coasting downhill, and occasionally while driving around.

My question is what are the chances that its just something in the head instead of the rings?
Anybody else ever had a similar issue?

91 std hatch, d15b1.

all other cylinders were reading 140+

 

perform a leak down test compression test are ok but leak down is gonna give you a way better idea to what is going on.

 

You must've done the test wrong mate. Even with clapped out compression rings you would still be getting SOME compression. Also your car would barely run and be nearly undriveable if it was only running on 3 cylinders.

 

i am going to say it is 100% likely that it is valves, rings, piston or block.

 

Yea I find it really weird too, running and 3 cylinders only... And it still runs pretty damn good!

 

That narrowed it down a whole lot...

-ZERO- Compression is typically caused by a hole in the piston, chipped/broke valve, cracked sleeve, broken rings, ect... The cylinders typically wear evenly and won't test out of 20% of each other be it compression or leak-down. To have such a drastic difference something is drastically wrong - or you did the test wrong. Judging by your other posts, I would say you messed up somewhere while testing.

 

 

well sadly enough my x-ray vision wasnt turned on then.
the point is without a teardown or proper diagnosis nothing can be said other than somethign is broke...either parts...or the tools/procedure....

 

go to the local parts store or garage and see if they have a scope that you can use for a min. stick it down the spark plug hole and that will tell you if you have a hole in your piston or cracked cylinder.

 

^^^ thanks man, i never knew that. i will try it out tomorrow!

and no i did the compression test correctly

 

Then you must not know what a smooth running engine is... haha.

 

UPDATE:

took the motor apart this weekend, ended up being a burnt valve! it was toast!!!

 

LOL