Xearo_FD3S

I just put a new engine in my car (40k miles, old one blew an apex seal). We checked the apex seals on this new engine and they appeared to be just fine. Now when we start the car up there is a mass of black smoke coming out of the exhaust and it is surging and not holding idle very well at all. We did a compression test the front rotor is holding about 125psi and the rear rotor isnt holding any. Could you guys please give me any input as to what this problem may be? Ive done much searching but have not found anything... please help, thanks=)

TwinTriangles

If your apex seals on the rear rotor arent blown they may just be stuck with carbon. Pull the motor out and try cleaning them through the exhaust ports with ATF and such until they loosen up and become springy again...

Xearo_FD3S

Is there an easier way, rather than pulling the motor out to clean the housings with ATF? Not that I have a problem with pulling the motor out, just dont want to do it again if I dont have to.

BigAl65

how bout fuel injector cleaner BK44 or marvel mystery oil in the fuel to maybe loosen them up....
just a suggestion....no flamage please.....

Xearo_FD3S

If my car werent getting enough fuel for whatever reason would that result in low compression? Or could anyone tell me what could cause low compression at all?

TwinTriangles

Not getting enough fuel wouldnt affect compression, Either your seals are blown, stuck & gummed up with carbon or your housing could be super warped I suppose. Im guessing on carbon build up. If you really want to get them clean and springy your probably going to have to pull the motor and work them for awhile as I stated before.

Xearo_FD3S

Well then I guess thats what I have to do, thanks.

mgoddard1

Severe flooding can cause low compression because the gasoline will wash all the oil away in the combustion chamber. Put a tablespoon of ATF in there, crank it for 20 secs, and see if that helps compression.

TwinTriangles

If he's getting zero's on the rear rotor its beyond flooded...

mgoddard1

dupe

Brent 94

iTrader: (1)

most likely, personally, i think you have a blown seal on the rotor you are getting no compression because the air is excaping when it's not supposed to.

mgoddard1

Yeah, if he's getting all 0's then either 2 seals are sticking or blown. Putting a tablespoon of ATF through the leading spark plug hole and cranking it a while may unstick the seals if that's the problem. The fact that the previous motor had blown apex seals may indicate improper tuning or some sort of lean condition and the same thing happened to the new motor.

TwinTriangles

Generally that will not unstick a seal in my experience it will just clean carbon from rotor faces. But its worth a shot I guess before you pull the motor again. It would be unfortunate if the seals were broken but that could be the case also