I'm going to look at a 2003 XKR tomorrow (114,000kms). I believe it has the very first of the 4.2L engines. Anything I should look out for? I'm very familiar with previous 4.0 V8, but not the 4.2L. Do the early 4.2s have any Achilles heel issues?

 

Here are a few weaknesses.




Diff oil seal
Rear offside Hub carrier bearing
Nearside track rod end
Nearside steering rack gaiter
Nearside rear shock bush
Rear sill/wheel arch rust proofing, paints underseal etc
Window down driver door clatter fix,
Rust repair around boot lock, free, done with left over sill repair paint
Trim touch up paint,
Headlamp fixing bracket repair,
Alien washer repair,
Oil cooler replacement,
Boot release button
Dash bulb replacements
Repair to reversing sensors
Replacement of rear bumper mount
Repair to rear bumper stiffener.
Replaced leaking coolant expansion tank
Replaced leaking cam cover gaskets
Repaired rust in tyre well
Auto lights on failure repair, new mirror.
Strut brace rust repair
Aerial mast replacement
New brake calliper
External A pillar trim replaced
Wiper spline refurb
Complete front suspension overhaul, all bushes, ball joints and wheel bearings due to poor handling
Front suspension turret welding repairs
Offside CAT converter welded up.
Evaporative emissions canister bracket replaced
Repaired broken door card plastic support
Replaced corroded earth strap
Placed transmission oil and filter/pan
Heater pump repaired
Nearside upper O2 sensor replaced
Lower offside O2 sensor replaced
MAF replaced
Steering column up down repair, failed
Steering rack replaced
Both rear wings welded to remove rust.

 

I have that drivers window rattle. Will need to check that fix out..Its annoying

 

@racediagnostics: seems like you had much fun with the car...

My 2003er 4.2 ( ~100000 km, bought with 83.000 km) needs new rear-shocks ( the wellknown rattling symptom). Also I had to repair one seat switch (broken), the seats airbag-connector (ruined by a shop) and the sun visors- that's it for the last 2 years. OK, to be fair, there are very light surface-rust areas at the end of the wheel arches

From my point of view, this model is far more unproblematic than the 4.0, except of the frame-parts ( I hope, this is the right term for wishbones, bearings and so on), but this mostly depends on how much care was taken by the previous owner. The drawback of this model is the availability of used parts. I was really surprised, how much parts were changed beside of the engine.

Good luck...

 

Since you specifically asked about the 4.2, I'll skip the general items about an XK8/R.

The 4.2 engine is pretty solid, and has a number of improvements over the 4.0. The biggest weakness is probably the fuel pump. It's an integrated unit, that has to be replaced entirely when it fails, so it's expensive. ~$1k including labor.

The other big difference is the ZF 6spd, which some say is less robust than the Merc 5spd but seems to hold up well in general. The one weak spot seems to be the early torque converters. There is a seal that wears out and the lockup clutch will cycle on and off. Later versions of the transmission have a revised seal and while you an get the converter rebuilt, it is a $300-400 repair plus the labor of dropping the transmission.

Change the trans fluid too, that sealed for life nonsense is bull.

 

My fuel rail was leaking when I bought the car and the intercooler pump had failed. If you smell gas on the engine it likely is the fuel rail. The part that breaks looks like it should cost .10 but you can't buy it without getting the rail.