2002 S60 low compression #2 after installing head

trv500 · Post by **trv500** » 13 Sep 2016, 16:36

started out with water pump locked up which threw belt and bent all the valves, so I put a used head on that I had checked for cracks, plained head surface, and vacumed test all valves, which were good. didn't have valves ground. low mileage car. set cams timing with tool on rear of head. all other cyclinder are running 170 to 175 psi,checked cam to lifter gap with cam lob up ? clearances are good. even put oil in cyclinder to do a compression check 140 psi, 135 psi before adding oil Haven't put plugs in and tried to start yet? cams are in right acording to part#, exh on top, Intake on bottom?
any Ideas???

zanzabar · Post by **zanzabar** » 13 Sep 2016, 23:54

Assuming this is a brand new headgasket? Could it possibly have shifted a bit when you put the head on and gotten kinked? Maybe it's just bad out of the box? Oh, and what was the exact torque sequence you used on the head bolts?

Does the psi on the low cylinder build up as fast as the others and then stop at 140, or does it take a little longer to get there? Which cylinder is it?

Do a leakdown test and see how fast the low one drops psi compared to the others.

Post by **precopster** » 14 Sep 2016, 04:27

Lots of engines run quite happily with varying compression. My customer's NA 1999 V70 came in with 120, 135, 140, 170 and 170 afew weeks ago. Drives like a dream!!

Start to worry with anything under 110psi. A Seafoam treatment will probably even them up and you'll be good to go. Most compression problems are sticking compression rings which Seafoam will correct