Under the rear of my 89 xj6, around the rear doors a buzzing noise is occuring after the car has been driven a while. The car is running fine so I'm not sure if this is something I should worry about? It has never done it before.

 

Hi Cole,

Welcome to the Jaguar Forums! It's great to have you with us.

I think some additional information might help us in our attempt to help you diagnose the buzzing sound.

1. Is the buzzing constant at all road or engine speeds, or does it change with changes in road speed or engine rpm?

2. Is it your sense that the buzzing comes more from the rear driver or passenger side or the rear center of the car?

3. Has the radio/cassette player been turned off when you have heard the buzzing?

By the way, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post an introduction so we can learn something about you and your Jag and give you a proper welcome.

Cheers,

Don

 

Thanks for your help. I would say the buzzing is primarily from the center rear and remains constant whether is car is driving or setting in the driveway. It does not start buzzing
when the car is first started, but only after it has been driven several miles. The radio was on when the noise first started, but I then turned it off and the buzz continued. The car sits a lot as it is my grandparents car, but this noise has never happened before.

 

My first suspect would be the fuel pump. If I remember correctly, on an '89 the fuel pump is mounted on the top of the rear suspension subframe to the left of the differential (left as viewed from the rear of the car). Perhaps the pump has become noisy, or its mounting bracket has worked loose and is coming into contact with the body and transmitting the buzzing sound into the passenger compartment.

A loose exhaust hanger can allow the exhaust to come into contact with the body, but usually the contact is intermittent.

The only other source of a buzz in the rear end that I can think of would be the radio power antenna motor. If the antenna mast's nylon gear cable breaks, the antenna motor may run longer than usual, but I believe the radio head unit will shut it off after a certain amount of time.

To track down the source of the buzz, you could leave the engine running, chock the front wheels, jack up the rear left wheel, and while lying alongside the car, use a long metal tool such as a screwdriver or socket extension as a "stethoscope." With your ear touching one end of the metal tool, probe around the fuel pump and left side exhaust components, listening for the buzz to become louder. If you don't find it on the left side, repeat on the right side, especially around the exhaust components.

Please keep us informed.

Cheers,

Don

 

I will jack it up as soon as possible or next time I hear the buzzing and let you know what I find. Thanks for the suggestions

 

I have the same noise, and have for years. Don, could be onto something in regard to the fuel pump. Long and short of it, I have never suffered any adverse effect from it, I thought it had something to do with the SLS being removed and just a result of those components missing, but that was done some 18 years ago..... I'll probably be punished for it now...

 

Rob and Cole,

For some reason reading Rob's post reminded me of one more issue that could be contributing to your noise. When one or both of the rear subframe bushings sags to the point that it allows the subframe to contact the body, rear end noise from the differential is conveyed into the passenger compartment. If your buzzing noise is louder inside the passenger compartment than it is outside the car, perhaps your fuel pump is vibrating a little more than normal, but its sound is being transmitted into the passenger compartment due to sagging subframe bushes.

Just a thought.

Cheers,

Don