Yea I thought it was alot. Does that tell me it was overheated pretty bad anif I put it back together with new head gasketsand it still shows low compression in that cylinder I can assume I have a sleeve issue? Im sure hoping thats not the case though.
Thanks

 

Hi Erik,
Bad compression after a head gasket replacement (and head resurfacing) and a valve job is most likely from a piston, piston ring, cylinder issue.
If you already have your valves off, may I suggest checking them for clearance with the valve guides. Generally the clearance you want between valve and guide is .003 in max. You would need a dial indicator for determining the clearance. Check the clearance in 2 directions, side to side, and front to back. You could probably lap your valves to get better seal.

Sleeve problem is another ball of wax. Mostly associated with severe overheating. Signs and symptoms but not inclusive, a rapping noise within the engine, high pressures in the coolant system, white smoke when initially starting the engine. If your head is off, when the liner is not flush with the top of the cylinder is virtually diagnostic. Carefully look at the top edge of the liner and the corresponding metal reinforment of the head gasket to see telltale striking.

Who knows there could be other sources of warpage. Maybe hosing your engine after an off trail run. Nothing like shocking a hot engine with a water hose. Just a thought.

Ed

 

Hi Ed, thanks for your advice. I have yet to install the resurfased heads with the new head gaskets to see if that was my problem. I didnt have any of those symptons so im hoping the heads were my problem. I didnt have them professionally checked before I did my first head gasket change(lesson learned there) an put it back together with two warpeds heads an a bad spot on the head. So chances are pretty good thats why it wouldnt run right for me and I had low compression in a cylinder. I had a pro check em out an he says they are both good to go now so we will see.
Thanks.

 

Erik,
Check you valve guide/valve clearances. Usually, the exhaust valves clearance goes before the intake ( exhaust valves are the smaller in diameter ). If you hear air rushing thru, coming from the valve cover, it can only come from between the valve guide and the valve stem. This would also mean that that particular valve stem seal would be no good. If your budget allows, may I suggest having your injectors sent out to be cleaned (approx $16 per injector at www.cruzinperformance.com/fuelinj.html ).
The composite head gaskets are suppose to be a little thicker to compensate for resurfaced head ( I haven't checked this out myself ).

I just finished doing a valve job/head gasket, plugs, plug wires, and coil on my 2000 LR Disco II with 98,000 miles. Looks like the injectors need alittle service too.
Ed

 

well I put everthing back together and it ran perfect for about 5 mins, then same thing poppin and misfireing once it got hot. I checked the compression again and same problem 120psi in #3 an 5 cylinders and all the rest have around 160.Guess ill be looking for another motor. Thanks for all your imput Ed an Mike.