Low compression on cylinder 4. Don't think its rings. What to do?

[headup240]

I just bought an sr20 redtop car. I did a compression test and the numbers were 150, 150, 150, 30. I checked the plugs and they were all fine except #4. There was some build up. No signs of oil anywhere. It doesn't smoke one bit, it runs fine it just shakes a little at idle. This car is my dd so I need to know what to do to save the motor before getting it fixed. Should I unlplug the injector? coilpack? I want to get around to taking off the vc to check valves. Can anyone help me?

[Z33dori]

bent or burnt valves

[199240sxcoupe]

put oil thru the spark plug hole and do the compression test if its higher then ur rings are gone.
also do a leak down to see if u got any bent valves

[titangts]

for driving it like that..unplug injector and that coilpack for sure..untill you figure out what you are going to do.

yea forgot about the oil thing..that works great..will show for sure if its the rings..but again the car doesnt smoke one bit...?

[nieko]

brooo if you have 30 psi... you need to take the fucking motor apart lol

either a valve is fucked or your rings.

either way, something needs a rebuild.

[headup240]

I just did a leakdown test at tdc. Air was coming out of the intake and throttle body. Intake valves not sealing?

[swestermann]

buddy of mine awhile back i had a sr that had a small bit of a intake valve was missing it idled like a miss but under boost it ran great had to pull the head to see what was going on and found part of a intake valve was gone turbo was fine so i just replaced the valve and it was back to normal

[headup240]

This is my daily driver. Would it hurt the bottom end if i drove it like this for a couple weeks? The car drives fine it just has no power. Should I uplug the coil pack and run on 3 or just drive it like it is?

[fliprayzin240sx]

I wouldnt even fucking drive it...thats how you make shit worst and fuck it up more than it already is.

[Rabboni]

Dude dont drive it. You might as well pull the head and fix the valve, which should only take a few days. On the other hand you could drive it and risk fucking everything up, then have to pull the entire motor, which will take more than a few days.

[xiaphin]

i'm with these guys ^^ one and two above