compression changed irregulary

[xka24detx]

i checked compression today after overheating and seeing alot of smoke come out of cylinder #4 head area the results are way off from when i checked it when i first got the car, i know its boud to change over time, but this change is confusing me... i dont know if something is blown, not sealing right, etc...
i havent tried the putting the oil in the cylinder test in #4 yet to see if it raises, just wanted to get your opinions
:tweak:
before
1=175
2=180
3=175
4=180

Now:
1=190
2=195
3=175
4=165

and to just add as a note #2, 3, 4 plugs looked to be burning good light greyish, but #1 was yellow, literally yellow, and on pdm's site on "how to read plugs" they dont say anything about yellow plugs

[mistert]

that is pretty strange, doesnt look to be a big enough change to be a blown head gasket

perhaps the yellow is old burnt up oil in cylinder number 1? I've found small bits of oil on my plugs before (everything is resealed now, doesnt happen anymore) but it wasnt burnt yellow yet

[zerogrips13]

if there is a difference between any cylinder of more than 15 psi there is a problem...

seems like u blew your head gasket or weakend it by overheating

[jdm_s14_zenki]

sounds like piston rings to me. #3 and #4 rings are taking a shit. might wanna try doing a leakdown just to make sure ur valve seals are good and valves arent bent.