Odd compression test results

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So I ended up having to replace a timing belt on my 2002 protege due to a failed tensioner and water pump. After doing the job, the car wouldn't start. to diagnose, I decided to perform a compression test as one of the steps. I got back some odd numbers compared to prior tests and am curious as to what could cause these odd numbers. results are in order from cylinder 1 to 4.

Results at 160k miles: 157, 152, 158, 165

Results at 210k miles: 149, 143,148, 159

Results at 240k miles: 138, 90, 141, 179

After getting the low number on cylinder 2, I decided to pour a spoonful of 2 stroke oil into the cylinder to see if the number would go up. It continued to register the same indicating to me, it is probably not a problem with the piston rings.

I know the valve stems are bad on cylinder 2 and 3 due to oil in the cylinders and on the spark plugs after sitting over night.

So a couple questions.

1. How would cylinder 4 go up in compression:

2. Should I have tried putting more oil into cylinder 2?

3. What are some other things to test why compression seems low in cylinder 2 without having access to an air compressor for a leakdown test? or could the valve stem seals cause that much of a problem?
 
Car won't start after timing belt change, odd compression numbers. I would recheck your timing belt alignment.
 
They are not preventing the car from starting. Oddly after performing a fuel pressure test and compression test, I decided to try to start the car again and it kicked on like nothing ever happened. It's also running smoother and quieter than it has in probably a year or two. I'm just more curious as to what may cause the compression readings.
 
Originally Posted by tomcat27
you say the tensioner failed. did the piston hit the valves? that would certainly drop your compression


In theory this is a non interference motor, so I wouldn't think that was an issue. But this is where i was headed. Some form of valve deflection or sealing issue.

Originally Posted by atikovi
Originally Posted by mazdamonky
I'm just more curious as to what may cause the compression readings.


What brand gauge? Made in China?


I was using autozone's rental OEM branded tool. It seems of decent quality and is the same tool I have used several times.
 
You ask : So a couple questions.

1. How would cylinder 4 go up in compression:

2. Should I have tried putting more oil into cylinder 2?

3. What are some other things to test why compression seems low in cylinder 2 without having access to an air compressor for a leakdown test? or could the valve stem seals cause that much of a problem?

1. carbon buildup on piston #4 can cause an increase in compression.
2. You don't need much.
3. Valve stems seals, guides and poor valve sealing likely are the problem(s).
 
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