Hey guys I bought my 03 s2k last July, and I ran into problems with it about a month later. It was random misfires, so I took it to the dealer to have it checked out had the plugs replaced and the coil packs checked out. It was still misfiring so they suggested a valve adjustment, so I took it home and did it myself and it cleared the code. Well I recently (2 weeks ago) installed some BC stage 2 cams and adjusted the valves to the specs of BC ( int .006 exh .008). Now I am getting the misfire codes for cylinders 2,3,4...great so I check the plugs and they look normal except for cyl 1 it had a bit of oil on it. Well I know the plugs are fine so I move the coils around and clear the code. I start it up and go to take it for a drive to get the CEL to pop up. I didn't even make it out of the garage the car would die when letting off the gas. So I decide to do a compression test ( after reading some misfire posts) so I warm the engine up again and the CEL light pops up so read it and it says misfire on cyl 3? Hmm but now to the point:

Here are my compression test results
Cyl1 240 240 240
Cyl2. 215 215 220
Cyl3. 140 140 140
Cyl4. 230 225 230

my question is what would cause cyl 3 to be so low (bent valves?)
Car has 118k miles on it and I'm 165 ft above sea level
I apologize for the round about way of telling my story, any help is greatly appreciated!

 

Retest but dump a cap of oil into the cylinder. If the number goes up significantly, you're rings aren't sealing. If it doesn't change it much then your valves aren't sealing.

 

Thanks for the tip ill try that now

 

Well after adding the cap of oil to the cylinder3 it jumped up to 170 170 160. Is this enough of a jump to assume my rings aren't sealing?

 

do a leakdown test, you might have a burned or bent valve, also make sure the valve adjustment was done right

 

Ill get a leak down test done and re-check the valves ill post back in a few days.

 

It's most likely your rings. If you have a bad valve, then the cap of oil trick won't jump up your compression numbers.

It's always that damn cylinder #3

 

 

well i havent done a leak down test because i am waiting on my leak down tester from harbor freight. I was bored so i did another wet compression test and it really but up my test results from 140 to 210 so i am pretty sure my rings need to be replaced. As mentioned earlier my car has 118k miles on it so i am just going to rebuild my bottom end with a 2.4l stroker kit! i want to stay NA for now...and FI later on. If anybody has any better suggestions for rebuilding my bottom end please let me know!