Compression depression :o(

[RSR1750]

Hey,

I recently took my 68, 1750 to my mechanic because it was running like a charf cutter and felt like it was not getting enough fuel or had some rubbish in the carbi's.  After they cleaned everything out and serviced it I was told that it was not firing on the first two cylanders on idle and a quick compression test showed approx. 180 - 190 PSI on 1,2 & 4 Cylanders and 60PSI on cylander 3........
I didnt have time to continue the investigation so it's goign back in tomorrow for another look.  But, after the service it feels like it is running fine.

Can anyone shed some light on this for me?  How much of an issue is it if I have low compression in 1 of the cylanders?  How big a job is itt o rectify???

Thanks All

[colcol]

To check to see what the problem is, do a compression test of the suspect cylinder and note compression, then pour about a small cup of engine oil through the spark plug hole, and do another compression test, if the compression goes up, then you have temporary sealed the piston rings, and it producing good compression, therefor you have a piston-bore-rings problem, if the compression doesn't go up, then you have a problem with the valves not sealing, so its valves or head gasket, you can put some test pieces in the radiator to indicate leakage into the cooling system from the combustion chamber, they are strips you put in, and they turn different colors to indicate any leakage, Colin.

[1750GTV]

A leak down test is also very useful.

Chris

[RSR1750]

Thanks guys, after a week full of stress and worry I went back to the Mechanic who repeated the compression test and had 190 PSI on all 4 cylinders.  I love a car that can cure itself )
Until next time, Thanks again.
Rohan