Jaguar Repair: compresson, wd 40, table spoons

Question
mr howard i have 86xj6 jag ben sttting 4 years low compresson what is the best thing to do #1 syl 60 #2 30 rest 90 to 120 dou think rings stuck car only have 126 tho// miles i pull valve cover did/nt check clarance.sp

Answer
Hi Jim,
The first thing is did you open the throttle when you ran the compression test? If not run it again with the throttle open. Next it to check valve clearance. If all valves are close to correct and none very wide. A large valve clearance is an indication of a problem. Bent valve, trash on the valve seat, rusted and sticking valve, weak valve spring from being compressed in one position for four years. Any of these are possible and as you say rings can get stuck in their ring groves and not expand out to seal.

If the valve clearance is ok, do a "Wet" compression test. put about 4 or 5 squirts of engine oil in the plug hole just after running a standard (Dry) compression test. (Throttle open) If the Wet test is more than 10% to 15% higher than the Dry test, it is most likely rings.

Sometimes you can get the rings to break loose from being stuck in the ring groves by soaking the top of the pistons with something like WD-40 or other penetrating oil. I have had some break loose after leaving about several table spoons of WD-40 on top of a piston for a couple of days, then spin the engine with the starter to blow any excess out. I added WD-40 to it the second day as much of it will drain past the rings.

If you can then get it to start sometimes they will break loose after running a short time. If they don't break loose after 30 minutes of running I doubt they will.
Howard