Hi all, a new member and starting my XK8 ownership with head gasket change. Good way to start right …?
Ive read and heard that using head gasket from 4,2 in 4,0 is recommended because the one in 4,2 solves the issue forever. Would be happy to know if someone has knowledge or experience of this. I have a 4,0 gasket from British Parts already but will then get the one from 4,2 if recommended.
Heads are now under professional check and within a week we will start the reassembly.
My car is XK8 4,0 1998 170tkm on the clock.

 

I'm not aware of any particular issue with the 4.0 head gaskets. Obviously, if the engine overheats then the gasket might well fail but that applies to any internal combustion engine.
I would suspect that different manufacturers use slightly different gasket constructions for the 4.0 and 4.2 so it's probably more important to get a gasket from a good quality supplier rather than worry about whether it is a 4.0 or 4.2 version, assuming that they are interchangeable.

Richard

 

The 4.2 gasket is multi layer steel and is superior. Do a search in the forum for more info.

 

The fibre gaskets (NCC2541BC for the LH) were superseded.

The 4.0 V8 engine from #0008311707 (2000 August 31 17 Hours 07 Minutes) onward uses the MLS gaskets.
The part number was AJ88193 (for the LH) when the supersede took place.

 

After reading many recommendations in the forum to use the 4,2 MLS gasket decided to go that way.
How about the process with head bolts ? Is it the same as with the original gasket and same torgue ?

 

I replaced several 2000MY XKR head gaskets with the MLS gaskets and Lincoln LS head bolts.(supercharged seem to cause the fibre gaskets to fail early?)

The Lincoln head gaskets will NOT fit the Jaguar block.

Jaguar switched to POLY DRIVE head bolts but I never tried them or replaced head gaskets on a LATE 4.0or 4.2 engine.

 

please keep posting here with the actual part number you used and if it fit. I am shocked that the head gasket from the 4.2 would fit on the 4.

 

AJ88987&88988 ordered

 

The MLS gaskets were FIRST used on the late 4.0 engines. Then continued on for the 4.2 engines. (the bores are THE SAME)

I used FEL-PRO ES72262 head bolt sets in the past when I replaced the gaskets on several 4.0 XKR/XJR engines. The engines are still running fine 10 years later. (I now own 2 of the cars I repaired years ago)

 

Do mls gasket mounting need copper spray or not ? Just heard that it is used.

 

I did not measure thickness but other measures between 4,0 and 4,2 gaskets are 1:1

 

it’s best not to use any spray or sealant.

the surfaces must be completely clean and free of oil. A white cloth dipped in paint thinner should come up 100% clean when wiped across the block and heads.

Z

 

Engine ready, compressions 11,5-12,5 in all cylinders. Car driven to winter storage 20km. So far so good.