Low Compression on CYL 4, Clanking noise, NEED HELP!

[vda240]

Hey guys, just a month ago got my s14 sr swap.

I need your help guys. Basically I bought the motor from a guy (S14 SR20DET) a month ago and recently when I started pushing the car I discovered that I had noise over 5K rpms, then after 2 days my car started running rough and shaking (on 3 cylinders). I pop off the coils to check them, they are in good condition, take off the plugs and find that they're wrong plugs. So basically I was driving with the wrong plugs for 3 weeks and now my car running on 3 cylinders and making a noise (sounds like its in the head). Did compression test, 1,2,3 are 160PSI across the board, 4 is 60 psi. Now before you say its a bad ring, I do not get any blow by whatsoever, and my car shakes, if I had low comperssion my car would not shake like this, it shakes like when you plug off one of the injectors it starts to idle rough. My friend who worked on SR's said its a burned valve in cylinder 4 (or both of the valve i/e) and that they need replacing. I also added some oil into CYL #4 and redid the compression test, and it didnt change anything (still had 59-60 PSI) Noise is coming from the head for sure, but cant figure it ot if its the valve or what.

I also popped of the valve cover and everything looks normal, valve springs are in good condt, and no broken rocker arms.

SHORT: Car runs on 3 cylI was DRIVING on WRONG PLUGS AND PUSHED IT HARD (no its not my fault)Low compressionMakes a noise coming from the headDOES NOT HAVE ANY SMOKE OR BLOWBYBurned valve?

YouTube - MOV02331 http://www.youtube.com/watch?v=zvf7sI80az0video

[Sil80315]

sounds like a valve train problem. Might of melted a valve running too hot of a plug.

[awhite69]

I got the same problem pretty much. Since you added oil and the compression #'s stayed the same its safe to say your rings are ok. I havent had a chance to look over mine, but i get blow-by at roughly 5k rpm and with low boost so I think i'm screwed with a bad ring. but i dont get any smoke either. when it stops raining this week i'm going to check it out. in the mean time i'm crossing my fingers its a valve. stuck driving my z31 til then

[vda240]

I did a leak down test and my cyl 4 showed 95% leakage... So basically my piston has a hole, because by adding oil in there it doesn't raise the compression so its not the rings. Anyway I'm pretty much screwed, but oh well... I was hoping its a valve but its not

[Sil80315]

Rebuild time!!..its a good thing to happen out of a bad scenario