Hey guys, I did a compression test on my car yesterday and the results were somewhat troubling. After seven or eight stokes, cylinder 1 did 125, and then 150 after adding some oil. All the other cylinders did between 175 and 183. Please tell me what you guys think that the problem is. Burn rings? Valves? The engine has 137000 on it. It still seems to run good but at rpms lower than 2000 there seems to be a slight miss if I floor it. Doesn't seem to pull as hard as it used to though. How long do you think this engine will last. Is it worth getting a leak down test done. If is just the heads, How much is it going to cost to get them replaced/rebuilt? Or should I just what till it blows up and replace the whole motor? Any comments would be well appreicated. Thanks.

 

all cylinders are not going to have perfect compression its going to varie from time to time depends on temp oil, gas, ect.. try up grading your oil to redline i have a 96 gle exhaust intake ect..with 136,000 miles it pulls like hell all the way to the redline im able to get to 130mph easly with the over drive off then i cut it back on at 130 and it goes 140 easily and this is with a bad o2 sensor so i thing your car is fine just upgrade fluids and stick with the factory spark plugs

 

a general rule of thumb is from 3-4 cranks i think 8 is a little high. but if you did a leak down test it will tell you where you are loosing compression from. therefore help in diagnosing your problem.

 

Was the motor warm? Ideally you want to test with a fairly warm motor and your compression results will probably increase.

 

not all vq30de motors will have the same compression. whats important is that the compression is the same in all cylinders.

 

Blows smoke out the back? Probably cracked a piston ring

 

You might have a coil pack issue.
Is your maintenance up to date? Plugs, gas filter, PCV?

 

If that were the case, I would think his compression check would be more even arcross the board?

 

I tested my compression today and it was as follows.

1..205-210
3..205-210
5..205-210

2..190-195
4..190-195
6..190-195
You guys know why the rear are all consistant but higher than the fronts?