Hi all,
I was delighted as I was getting the results of the compression test, 175, 180, 175, and 180. My delight evaporated when I checked the manual and it said compression should be 140-160. The guage instructions said this likly meant carboned up compression chambers. I usually often drive at 120 kmh, but usually stay under 3000 rpm. I've owned the car(145 turbo)for two years,. Is there a way to clean out the chambers without dissasembly? Should I worry about this at all? Might the commpression test results be in doubt? (I didn,t remove the air cleaner per printed instructions and, of course, didn't tie open the carburator throtle plates).
thanks, jim s

what manual is telling you this? if i recall, the FAQ says 128psi is the minimum, and they should all be 28 psi within each other. didn't specify a maximum

"When the compression is found to be too high in one or more cylinders, this would be an indication of excessive carbon buildup in the engine. It can only be corrected by performing a chemical de-carbonizing process on the engine or by removing the cylinder head(s) and physically removing the carbon that is attached to the cylinder portion of the head(s) and the tops of the pistons."
--
Kenric Tam
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'

Thanks for the answers guys, what a great forum. I got the compression specifications(131 to 160) from Haynes Volvo 740&760, 1982 thru 1988, Ivar. And I did warm up the engine Haroon. Thanks to Hoyt too, I now know that I've got an air mass sensor and it's in danger. jim s.

it's fine. Mine were all 180, and I think thats no problem. I do recall specs of 180 somewhere.

Did you do yours on a hot engine? My cold ones were 180 all around.

it's fine. Mine were all 180, and I think thats no problem. I do recall specs of 180 somewhere.

Did you do yours on a hot engine? My cold ones were 180 all around.