Hi guys
I have been searching this forum for hours and i just can't find my problem anywhere so i thought i might ask to see if someone recognises the symptoms.

I have a 1998 XJ8 3.2L , In drive, and only in drive it reaches 45 mph and starts to rumble. This rumble continues the faster you go and seems to get worse. In sports mode or in the locked gears ie. 2nd, 3rd, 4th it drives perfectly to over 90 mph but as soon as i drop it into drive it starts to rumble. It's as if it suddenly switches of some cylinders. This rumbling is accompanied by a strong burning smell, plastic or rubber but it smells toxic, if you know what i mean. This smell seems to be coming from behind the engine under the bonnet but i can't identify where.

After the car does this the engine ticksover at about 600 and if you drive forward or reverse at tickover it lurches quite harshly as if the engine is missfiring. If you park and leave the engine to idle it smooths out after a few minutes or if you don't want to stop you can just put it into sports mode and the problem goes away until you put it back into drive.

Anybody seen this before?

Thanks

 

One other thing, the rumbling also stops when i back of the throttle, even slightly.

 

anyone ??

 

At a guess, you have transmission problems.

If you lack the experience to identify the noise, then perhaps a shop can have a listen.

 

Is this car new to you, or is this a new problem that never happened before?

If this is a long wheelbase car, it may be an inherent flaw in the system. I know the old XJ8 VdP does this. Two veteran Jag mechanics were telling me that Jaguar lost a lot of warranty money because of this design flaw.

When my 1998 XJ8 gets to around 60mph, there is a low grade vibration from the back. My friends with the same car also have this. The original owner of my car complained to Jaguar, and they 'threw parts at it' while it was under warranty. My car has 59K, and I learned that the first thing Jaguar did when the customer complained at 20K miles was to replace the transmission. They next replaced the gearbox when the issues persisted. Good for me. I hope it's nothing big in your case.

 

toque converter bearing?

 

Hmm Torque converter bearing, possibly, there is a hissing noise like an air leak coming from the gearbox area at tick over. It's only done 80,000 miles and has been regularly serviced. I bought it 2 weeks ago and it ran beautifully then 2 nights ago it just started rumbling as if it was badly missfiring but it only occurs in 'D' drive at 45 mph upwards. Just want to know if it's worth fixing, the car is just a run around i picked up for £700, was going to use it for a while until i could get a newer model s type later in the year.

 

Hi John, in my lay opinion, it sounds like top gear is failing inside the automatic transmission. If the machine can run up to 90mph in the lower gear, that rules out engine difficulties I believe, but rules in trans problems, which occur only in top gear. A bit more info could shed further light, like, vehicle mileage, service history, etc. I was given sage advice years ago: "if you can drive the car into the trans shop, the rebuild is significantly cheaper". I would do that, and have the qualified mechanic examine the fluid and drive the car with the info above. How great would it be if it just needs a thorough trans service like a flush and refill, which did wonders for my car. Best of luck and please post what happens next with the Cat.

 

Hi, you have no information on the dashboard?
The light on the gear, when you are in "D" is on?

Marc

 

I can't remember if there is a center support on the driveshaft but if there is one it deserves a look with this type of complaint.

 

Ken - good call, there is a propshaft bearing....a great big one. But how would it decide not to rumble in Sport?

 

The difference in sport versus non-sport *might* be torque converter lockup

 

Thanks for all the advice. Things have progressed, not for the better
I've been driving it around trying different speeds, gears, etc and now it rumbles in all gear ranges. In 4th locked, or D drive it starts at approx 45 mph and now it is rumbling in sports mode at and above 70 mph. I think the difference in speed possibly rules out the transmission ( drive shaft / gearbox). When i accelerate, ie kickdown it stops vibrating and when i back off the throttle it also stops. If i accelerate slowly it rumbles heavily like the engine is loose.
The latest is the exhaust has sprung a hole and at idle it sounds like it is miss firing.
Could all this be caused by the ecu compensating for an exhaust leak? I'm puzzled.

 

a misfire could be oiled up coil(s), bad plugs, over fueling, fuel pump going out etc. Has it got any warning lights on? Have you got a OBD reader?

Also maybe time to get a look underneath and see where the leak is, if it's around the cats/manifold then we can understand more.

If you can't diagnose, maybe time to take it to a specialist.

 

The exhaust is blowing just below the left cat but there are no warning lights on the dash. Is it possible the exhaust leak is unbalancing the engine?

 

pls help. im very happy just got 2 days ago my 02 xtype. has 78k miles and thanks to this forum i fixed the psngr rear lights that were out.
i have a similar problem: a noise after 30mph that sounds as if air was escaping or a rattleing. runs smothly, shifts gears properly. after 60 or 65 the noise fades completely. ??? im very puzzled. and totaly new with jags, we got it waxed today with my wife. but we scared. the transmition sounds good while below 30mph or after 60. but in between we get this buzz. no vibration, or other things, just the sound like a thousand bees are under the car by the engine or transmition but under. many many tnx. and let say im very impressed how high tech and helpful this forum is. i had to sign up. i read over 5hrs of posts yesterday.

 

When I turn the car on, the engine runs smooth and the car is quiet until I start to drive. There is a ticking sound when I accelerate which gets louder and more rapid as I accelerate. When I take my foot off the gas the noise is not there. I've read that this may have something to do with the driveshaft? Can anyone provide some feedback? And to be sure this is a ticking sound, not clicking or vibration or rumbling..

This is a 2003 Jaguar X-Type 2.5L AWD