I have an 02 XJ Sport with about 106k miles on the clock. On cold mornings, cold for us in south Texas is below 40, after starting the car and pulling out of the garage, I hear an odd whining noise coming from under the hood. It isn't a clicking sound, more like a motor noise or belt whine. This only happens on the first one or two accelerations then goes away, and only happens below 40 degrees outside temp. Any suggestions as to what it might be? It would be pointless to take it in unless I left it overnight on a cold evening with a mechanic who would be sure to start it up early before it got warm outside.

Thanks

 

Alternator whine? Is the whine frequency somewhat higher than the engine RPM?

 

Strange we have another situation on the xk8 page https://www.jaguarforums.com/forum/s...ad.php?t=32853

 

hughey, we need to get our parts, meet somewhere, and change out our belt tensioner, idler pulley, and drive belt in one day. With the help of gus and gordo, i'm pretty certain that is the cause, though one or the other is difficult to determine.

(from gus's page)



Mine seems to be more prominent on the upper right of the engine (looking at it from the front) so that leads me to believe it is the belt tensioner. However, if I'm going to change one, I might as well do both. The idler pulley is also known to have a limited life span and will eventually end up the same way, so another $50, its coming out too.

Here's a pdf link with some more 'troubleshooting' ideas based on the sounds we're apparently hearing.

 

Matt,

I listened to your sound clip and the sound is very similar. Mine doesn't start until I am in drive and moving at acceleration. Harder acceleration gives me louder sound. The sound goes away after the second acceleration ( I have a stop sign at the corner of my street). By the time I get another block and turn again, there is usually no sound. I tried to get the sound to reproduce while idling in the garage by revving the engine in park, but didn't get anything. Once I pulled out of the garage and started down the road, the sound came up. I'm going to try turning of the a/c next cold morning and see if that does anything. Also will try turning the wheel while still in park to see what happens. The sound is definitely not regular belt whine, but the pulleys could be the source.

I'm all for a mechanic's day. I need to replace the timing belt tensioners, too, since no one can tell me for sure that mine are not the kind that fall apart or the metal ones. My car is an '02 XJ Sport with a build date of August '01. This is my work car and I need to have it running every day. Otherwise I would have to take the XKR to the high school where I work, and that ain't happening again!!!! I have a four car garage, but it opens to the back yard, so not a great place to work on cold days. I'm off for spring break in March. Maybe I'll try to do something then.

Paul

 

August '01 was the critical month on the change over to the metal tensioners. Your local Jaguar dealer can provide the engine serial number from your VIN. The first 6 digits are the date of engine assembly (YYMMDD). The critical date is August 13, 2001 (010813hhmm). After that you should have the metal tensioners. Might save pulling the valve cover.

Matt, you have gotten very good with attachments.

 

I tried that route the last time the XKR was in for warranty work. The dealer didn't seem to know what to do to find the engine serial number/build date. Perhaps I wasn't specific enough. I'll try that again before I give and and pull the valve cover. That needs to be done eventually, as I have a slight gasket leak.

Thanks for the info.

 

The engine number is stamped on the top of the engine, left front, by the thermostat housing - you can read it with a properly aimed penlight without having to disassemble anything. It will tell you the date and time the engine was made, eg engine number 9810210631 was made October 21, 1998 at 6:31AM.
________

1999 XJR

 

Matt,

Good idea to change them both at the same time. Nice link!