I have 97 XK8 with 54K miles -- I hear a grinding noise at 32-40 mph only with a slight load on engine. No noise when in Neutral and coasting at same same speeds. Engine has had new Secondary Cam Chain tensioners installed and has never had any engine or transmission issues.

The noise sounds like a plastic fender liner rubbing on tire - BUT there is no evidence of any plastic contact .. and sound will stop immediately if I shift into Neutral from Drive

Sound will stop immediately if I let off the gas or press the gas pedal down

Engine runs great and has no acceleration problems or noises.

It's hard to pin point the origin of the sound. It will reoccur generally between 32 to 40 Miles per hour. Sound Never occurs going downhill.

Any Thoughts will be greatly appreciated ?

 

I think you need a passenger to help identify the location of this noise whilst you carry out the necessary driving conditions to make it happen. The passenger can move around to better trace the source.

Taking all the factors you've listed into account, it could be suspension, transmission or driveline and this covers a lot of possibilities.

It could also be transmitted vibration from failing metalastik mountings on suspension, engine or transmission.

First try to identify whether it's coming from:

1. LH or RH
2. front or rear
3. midline

and also whether holding in a lower gear still brings it on at the same speed range. This will give a better clue where to start looking.

Graham

 

Could it be drive shaft related? Just throwing that out there. Grahams right..you probably need a passenger with a head out the window/ or to hold the steering wheel.

 

I appreciate the replies so far and the useful insight

The lower gear evaluation will be done this weekend

What about a Transmission Pan removal and check for metal debris ? How is this done ?

Noise Location identification has proven to be extremely difficult, I may put rear wheels up in air and see if I can reproduce the noise; but this will be no or little load and I doubt noise will occur.

Thanks
Steve

 

My similar problem was resolved with a lot of very expensive new gearbox oil! See:
https://www.jaguarforums.com/forum/x...5-50mph-88626/

The noise from the rear was the gearbox noise transmitting through the drive shaft.

 

i have xactly the same problem. i have serviced the box , new filter ect , but i could only get about 2 litres of new fluid in ther. how can i fluch the torque converter and change the lot , around 9 litres iirc? . if i drive the car hard there is no issue. it only happens under slight acceliration at around 45. if i pedal hard or drop a gear manually it goes and the box it fine. as the car id making the niose the revs fluctuate slightly.

 

You describe this as a noise specifically relative to throttle position...is it really that consistent? I ask because I have had a grinding noise that seemed to come from the firewall area, or near the bell housing, was hard to pinpoint. It would come and go, but didn't really seem related to throttle or load. It all started one day out of the blue at a stop light and lasted only a second or two. Then again a week later, then more frequently. Once in a while it would stay on for 30 seconds or so. It really is quite loud. I finally realized that the noise would go away if I shut off the climate control. So I thought oh no, the A/C compressor was going bad. After putting that off for a while, it became even more frequent. So one day I tried hitting the A/C switch rather than shutting off the climate control completely and the noise stayed, so, not the compressor. It turns out it is the aux electric water pump, which sits just near the bell housing. The pump is going bad.the pump will cycle on and off depending on demand and engine temp etc. Unfortunately, it will be $1200 parts and labor at the dealership...I think access is from underneath by removing the exhaust. That also includes replacement of all the small hoses to/from the pump and control valve and heater core. Ouch. Anyhow, not sure if this is what anyone on this thread is experiencing, just thought I would throw out my experience. There hasn't been all that much on the forum about this pump going bad.

 

There have been many threads about the heater pump, here and on XJ forums. It usually requires new brushes, and does not require removal of the exhaust system. But of course, the dealer only replaces parts, never rebuilds.

 

dr_jekyll

Did adding the 2 litres of new fluid stop the grinding noise ?

My Dealer --> Gearbox drain and refill $519+ tax

My noise ONLY occurs under slight load of acceleration; never when coasting, or not moving.

Revs do fluctuate slightly - noise is from something putting a little drag on the drive train which so far is impossible to pinpoint. Thanks for the replies

 

no still the same. did the full flush and replacement fix yours?

 

A common issue related to drive train noise has been the universal joints located in the rear you have 4you have 4 of them 2 on each side. The real problem is that they are never lubricated. I would have them checked first.

 

Has anyone found a solution yet ?
I have exactly the same problem.
Is this the torque converter slipping ?
Does transmission fluid change and gearbox oil change fix this problem ?

 

I can add a little more info.

As I stated above, the gearbox oil change removed most of the noise, although I could still hear it a little when under load at these speeds. I took the car in for some laser wheel alignment with a local specialist I found and whilst doing this he spotted that the rear drive shaft on the drivers' (right) side needed lubricating - the same side as the noise. I hadn't told him about this so he had no reason to suspect anything. He said that many garages don't have the right grease gun for getting the grease in so don't tend to lubricate this. I didn't think about it again until your post prompted me to realise that this must have fixed it as I've not had the slightest noise since then!

Hope this helps.

 

Not being a mechanic, the short version of my reply is probably best read as "What Gus said works".

 

I have the same problem, the sound is like running over a wash board it's the clutches in the torque converter. If you have a lot of miles on your gearbox (178000 on mine) you may not want to change the fluid as it most likely will start slipping. You can get a new torque converter for about 262.00 and up on Ebay but the labor to drop the gearbox and reinstall it is about 800.00 plus, at this point you an extra 700-1000 dollars and you can have your gearbox totally rebuilt (2700.00 + tax)
There is an additive called Dr.Tranny shudder fix by Lubeguard it costs 6.99 and you can find it at most automotive stores as well as Amazon and Ebay.
This is not a permanent fix It will buy you time and keep those clutch fragments from chewing up the rest of the gearbox
Another way to buy time is to use your J-Gate and not let the gearbox go into 5th gear

 

I have the same issue. Has anyone figured out a solution? My noise seems to be coming from the left rear and occurs in drive as well as 4th gears. It does not occur under moderate or hard acceleration.

 

I had this fixed before. If I remember it had to do with the torque converter sliding towards the rear on the shaft so it would rub the bell housing or plate in the transmission. A certain light load on acceleration would flex everything just enough to make the rubbing/metal on metal sound. My guy slid the converter forward and the noise went away. Not sure if there is a set screw or something to hold it forward on the shaft. I will check with him again and post if I get an answer.

 

I had a similar sound, only in high gear, under acceleration and between 1200 & 1600 RPMs. I greased the universal joints on the half shafts, they really needed it, and no more grinding noise. I think I caught it before any damage was done. Just something else to check. Cheap fix also.

 

If the sound goes away in manual mode ie. 4th gear its the clutches in the torque converter and for what the labor cost is for gearbox removal you should just have it all rebuilt including the valve body, tc, and gearbox. then have your tcm reprogrammed and do not use sport mode for at least 800-1000 miles so the tcm can adapt

 

Anything new on the grinding noise between 35 and 50 mph under light load? I still have this issue on my 2001. Hasn't gotten worse, however.