72 Jaguar XJ6 4.2 litre motor reliability?

[karls59tr]

Did these engines have any notable weak points or reliabilty issues. Reason for asking is there is a complete unit going locally for $149.It has the starter,trans,Strombergs etc. e Was pulled out of the car many years ago. I'm contacting the owner to find out if it had any issues or is seized but I was wondering if those units had any inherent problems that caused them to fail?

 

[Deleted member 8987]

You mean other than being British designed, engineered and manufactured?
Normal head gaskets, oil leaks, the stuff you'd expect from your 4-cylinder MG or TR magnified by two more cylinders. Jag engines don't like to sit.

That said, and memory time here....there were two different head stud designs on a 4.2L. One set went almost to the main caps. Corrosion and "working" tends to make these...an issue getting out. I know of shops that have stud pullers to remove studs just to get the heads off. Usually break one or two doing it, and if they're the long ones, fun getting them out.

Cranks. Tend to bend under heavy use, but straightenable.....TuffRiding (?) tended to CAUSE warped cranks, which then required a straightening process afterwards.

4.2L was about it for bore, which made the walls a tad thin. Can't recall off the top of my bald spot whether those were more prone to cracking.
Should have lifter guide plates installed.

 

[karls59tr]

Good to know.Thanks for the info.

 

[equiprx]

Best engine Jaguar ever put in the e-type. Simple design and all the important upgrades from the 3.8 liter. The block is almost as heavy as a v12 though. Cooling system is prone to corrosion build up.

 

[DrEntropy]

I'll go a click further... IMO the 4.2 is Jag's zenith engine. Maybe not as high an output per cube as the newer ones but about as reliable as a Swingline stapler for doing its job.

Should have lifter guide plates installed.

I've made/installed the bucket sleeve retainers for a few. Only seemed necessary if the OWNER(S) let the thing overheat severely at some point.