disco 2 2000 220k miles. 2nd head gasket replacement.

i had low compression in cylinder 5 only. engine was eating coolant no coolant and oil mix at all.

my question is i pulled the heads off the left side and took a look at the head gasket...i did not see any broken ring or blow through at all...it is a land rover gasket. do these gaskets fail in the layers and not visible to naked eye?

since i didnt have normal compression in #5 im thinking the bolts were a little loose that might have contributed to the problem.

when i looked in the head and cylinder for #5 i fully expected to see a steam clean situation but did not see anything at all...all heads and cylinder were the same carbon buildup etc.

i also checked the head for warpage and i could not get a 2 thousandths feeler underneath the head...

 

No signs of coolant leaking externally at the back of either head or intake/stains visible on bell housing?
Which of course would be bad for cylinder 5's low compression, meaning the 2 problems were unrelated.
If you rotate the crank by hand, does all visible area of cylinder 5's wall look ok, no scrapes, lines, or damage, like from broken ring(s)?

 

Did you have any misfires on 5? Are you sure the missing coolant was not getting in that cylinder and burning off?

 

He says none of the cylinders/heads looked steam cleaned.
Which is what makes the losing coolant thing so strange.
Unless it's an external leak, and #5 unfortunately has it's own issues.
I couldn't tell from above if he has removed the other head yet, and if not, the leak may be there.

 

Sounds like two issues as noted

Coolant loss - you need to do a pressure check and thoroughly check very hose and the engine compartment and find out where
Low compression - that can be a few things, could loose bolts, bad gasket seal, bad rings

 

to be brutally frank, the engine is so covered in grime/slime/black tar like substances i cannot see any clear evidence of coolant trademark white stains. i did see some white stains around the coolant heater hose to tstat junction but again that could be old.

the car never gave any misfire codes whatever.

i was losing a fair bit coolant as the reservoir tank would go empty after a couple of drives 3-4 days of basic errand running around town etc.

i did compression test all cylinder before tearing it down. and number #5 was 30-40% lower than the others which were all a close grouping..

i do have the tapping noise which is infamous...but did not affect driving and was like that for several years.

the last head gasket changed was around 110k miles

usually when i inspect a head gasket i can see the blow by especially between the cylinder rings where exhaust escaped. i do not see it here.

i have yet to remove the other bank right bank, and will do shortly and report back.

i really was expecting to see a steam cleaned #5 cylinder.

i do not see clear scratches on cylinder wall of piston ring failure but its hard to tell since i can only see top of piston. i will rotate engine and see what i can find...

 

since i replaced last headgaskets at around 100k...all the evidence (1) loss coolant in reservoir (2) tapping noise (3) mileage now 220k (4) loss compression #5 made me think that head gaskets are to blame and they still might be bad ...

also i do not see any sleeve that is above or too below the rim...so im just scratching me head here

 

If the sleeves were moving up and down they should have left a noticeable impression on the bottom of the head gasket.
I belive sleeves can slip, but I also have a hard time beliving that they always stop in the correct placement. I would think that one would have to be too high or low in the block at some point as well.

 

When I replaced the head gaskets in my truck 9½ years ago the only problem I could see was a defect in the narrowest part of the headgasket behind cylinder 7. There's not a lot of gasket material there to start with (maybe 3/16", IIRC). But it was enough to cause a leak big enough to warrant fixing.

 

update: no impression markings on bottom of head gasket from slipped liners. the metal rings on gasket are smooth and all there for all cylinders on left bank.

but i do have that tapping noise chronic...so maybe now im thinking oil pump gears and bearings.

before i tore apart engine i forgot to do an oil pressure test...but i never got low oil pressure light 6-7 psi. so it must be above that.