Just completed a 1100 mi trip in my newly acquired 98 XK8. All good and even got almost 26 mi per gallon at mostly 80 plus and plenty of hills. I've noticed a whine, seems to be from the engine upon acceleration, doesn't matter what gear. Never noticed this in my other XK8s. The odd thing is that it doesn't do it in cruise control ? Anyone experienced this or have any explanations. Thanks.

 

Thomasso, I've never had this problem in my 98. Can you say more about it?

you mentioned that it doesn't happen in cruise control, not sure exactly what you mean about that. Since accelerating doesn't happen in cruise control, unless you push resume. But that begs the question: how hard are you pushing the accelerating when it occurs?

hate to leave you hanging but maybe we can help if you can say more about the sound (volume, pitch [tied to engine speed? Mph?] Location[engine, wheel, suspension-front is unweighted during accelerating right?]; more about driving conditions...

Any chance it could be the idler pulley? Common failure in 1998, and it can make some weird noises including whine.

well you get the idea. I look forward to hearing more..

John

 

The whine occurs on all throttle pedal acceleration, stop lights or mountain passes. Hard to describe a whine, but I would say about medium. My wife and I have different opinions about where its coming from, she says rear. Actually acceleration occurs in cruise control, resuming speed, adjusting speed with plus button, and just maintaining speed i.e. mountains even to the point of downshifting to maintain speed. No abnormal sounds at idle. I've not had a chance to check out much of anything on car yet, it still has plastic coolant filler ,thermostat pipe. 65,000 mi. Have a few things to do to my XKR, brake lite switch etc. as it is sold. Will check out the XK8 soon and get back. Thanks.

 

May not be your problem, but I had a whine on acceleration, and it turned out to be the Serpentine belt tensioner pulley and idler pulley.
I thought it was the tranny, and it only happened under load / acceleration

 

+1 On the 1998s idler pulley. Mine made all sorts of noises at different times. Good point Anthony.

John