XK8 4.2 engine and gearbox rebuild costs

[andyps]

I've had my X100 for just over 5 years now and still love it. It has clicked over to 170k miles today but (touch wood) seems to be running fine. The reason I'm wondering about rebuild costs for the main drivetrain bits is because I can't think of a car which suits my needs and budget better than the X100, mine is a great colour combo and the cost of slightly newer, low mileage ones seems pretty high. That got me thinking that maybe I should just be prepared to get the major bits rebuilt if necessary but I have no idea how much that might be and if there are any recommended places to get them done - any answers would be appreciated!

The main alternative car I have considered is the X150 but I think I would really struggle with the much smaller boot space - mine is a convertible and I much prefer it that way!

[Orcadian]

Presumably you are talking about rebore, new pistons, crank grind - if that's possible on these units, new shells, oil pump, gaskets and the like. I don't want to be too pessimistic but having followed the frustrating tale of this guy on here with the XFR, there are lots of places on an engine rebuild where mistakes can be made by slip-shod workers. This sounds like a really big bill but at least you will still have the original motor. There are many very experienced companies who rebuild engines who advertise in the Jaguar magazines - that would be my first enquiry. Have you considered buying an engine and box from a low mileage breaker to put on one side? Eurojag might advise if they have something and price. I don't think there would be much difference price wise.
Apart from something letting go on your unit, you will usually get some idea that things are wearing out - increasing oil consumption.
At least you have one of the latest and best built examples of these lovely engines.
Ian

[andyps]

I guess what I am talking about is whatever it would take to make the parts do the same mileage again, if and when they need doing.

I did replace the gearbox with one from Eurojag about 2 1/2 years ago (although having read more since I think the main problem was probably the torque converter) and still have the original box. Trouble is it is getting harder to get good parts from Eurojag it seems - I waited a few months to get an aircon pump from them last year. The whole matching numbers thing frustrates me but if I am keeping the car because I like it and the values are heading in the right direction to justify spending money on it having matching numbers does then become more important for the future value of my car.

I'll get a copy of Jaguar Enthusiast magazine and have a look at the ads - if it has to be done one day I want to make sure it is done properly. Hopefully won't need anything for a while but it is part of the decision making process about keeping or changing the car.

[Orcadian]

Yes, the prices are certainly on the up for good ones. I think if you change the engine, gearbox and final drive oils, perhaps a bit more often than dealers would - and use good stuff - then you should get a lot more miles yet. How many miles did you do in the last five years? The editor of the JEC mag, Nigel did well over 200k in a 350 V8 without serious issues.
I still think keeping rust at bay is higher up the list than miles covered.
Ian

[andyps]

Orcadian said:

Yes, the prices are certainly on the up for good ones. I think if you change the engine, gearbox and final drive oils, perhaps a bit more often than dealers would - and use good stuff - then you should get a lot more miles yet. How many miles did you do in the last five years? The editor of the JEC mag, Nigel did well over 200k in a 350 V8 without serious issues.
I still think keeping rust at bay is higher up the list than miles covered.
Ian

At the moment I'm using the car a lot, I've done 80k miles in it since I got it so averaging 15k per year plus. I'm looking at ways to reduce that through using another car for some of the more mundane localish journeys. You are right about rust, I've just had the rear wheel arches sorted and a couple of bits on the floor so they should be OK for a while yet but now need to get the front of the sills sorted as they are beginning to buble slightly.

[Orcadian]

Hm,
Arches, floors and now sills. If you are really besotted with the X100 (as am I with my 308 Super V8) might you be better tracking down a low mileage cosseted example, even though it would need good money and lots of VERY careful inspection before committing?
Just a thought! Numbers might end up about the same.

Ian

[P700DEE]

You have a 4.2 engine , they are good for huge mileages without a rebuild. What you should consider is to change the chains and tensioners, they may be the improved metal bodied ones but at 170k miles there will be wear and chain stretch so a preventative maintenance change is a good idea. VVC valves wear and replacing components in the cooling system , water pump , thermostat and all those pipes especially the valley pipe. Radiators have a tendency to start to fail around the 10 year age mark so swapping these will be necessary at some point. The main engine should be fine with regular use and the usual oil etc. Best keep running it , dropping to lower annual miles won't do the car much more good. Suspension will be the other regular cost.

[andyps]

Thanks for that, a good suggestion about the chains and tensioners. I did the cooling bits last year as I noticed that the hoses were bulging - pain of a job but good to know that they are OK. The oil gets regular changes and I've always used the recommended Mobil oil. Good to know that they are OK for high miles!

If I reduce the mileage it will probably only be down to 10k per year - basically thinking of cutting out the really short journeys in it where it barely gets warm such as the 3 miles to the office type trip - I have a classic Mini which needs some work but would be ideal for that trip, using the Jag for other journeys which would still be a few times a week.