Grinding noise from rear, XK8 1997

[sifitz8]

Hello everyone. I have owned my 1997 XK8 coupe since 1999 and its covered 94k miles. Its been well looked after and cared for with full service history etc. Its covered very few miles in the last 4 years, less than 1k. The sun finally came out and took it for post lockdown run, only to find I have a new noise. 

It only occurs at between 40 to 55 mph, on a light throttle, on the level or slight uphill gradient, its brief and difficult to maintain, and it sounds like a heat shield vibrating against the exhaust, only not that easy. It doesn't do it coasting or under hard acceleration. Runs perfect otherwise, gearbox changes ok and motorway speeds are fine. Still runs as it should and as it always did.

I have done some internet research and quite a few cases of this problem can be found. Exactly the same as mine. What I can't find is a solution to the noise. Various attempts ranging from replacing gearbox Oil, catalytic converters, universal joints, differentials, shock absorbers, etc. The car is currently at my local prestige car repairers. They actually specialise in Aston Martins but up until now have never let me down. They seem to drawing a blank, and we are getting into the realms of randomly replacing items and hoping. As you are all aware thats an expensive game. 

Just wondered if any learned person on here has had the fault and actually cured it, or has known or encountered this on their travels. Its a pity, because the car is really very good, all rot in the usual places, front suspension, floor pans, rear chassis legs has been attended to properly, but I can't start throwing large sums at it aimlessly. Anyway, I can live in hope that someone will have the answer. Thanks.

[sifitz8]

Just an update on this problem should someone else in the future have the same issue. A gearbox service cured this strange noise. I had had the gearbox serviced before at 55k miles, but it needed doing again at 94k.  The proper Jaguar automatic transmission fluid is costly, but the filter and gasket are cheap. Just be sure to get it done by a garage that knows what they are doing. Its quite a long drawn out procedure to do it correctly.