Thread: Intermittent unusual noise

Where's the video?

Can't see a link to a video. Just to clarify, can you give an indication as to what speed (or range of speeds) you hear the sound? Have you had the gearbox serviced, preferably by a ZF approved agent? At 135,000km it definitely should have been done at least once, particularly as you tow a heavy van.

A bit hard to be certain if it's LHF or LHR wheel, but it sounds like it's at wheel rotation speed, I'd be checking very closely for a rock or stick getting picked up between the brake rotor and backing plate.

Apologies for the delay in getting the video up.
When it occurs the odd noise can be most easily be heard between about 20 to 60kph but also evident at higher speeds.
It first was noticed doing slow creek crossings and steep climbs on the Bloomfield Track.
The transmission has been serviced twice by Ron Hill Automatics at Maroochydore who have been operating since 1975 and regularly service Discos and other cars with ZF transmissions. The last service was at 126,000 k’s in February.

Originally Posted by discorevy

A bit hard to be certain if it's LHF or LHR wheel, but it sounds like it's at wheel rotation speed, I'd be checking very closely for a rock or stick getting picked up between the brake rotor and backing plate.

Thank you. Will do.

It does sound more like an interference noise than a mechanical one. I'm surprised the underbody check didn't find anything as they should have looked for something fouling the discs as Discorevy has mentioned. I'd crawl under and have a good look around at all moving parts like prop shafts and axles and then remove each wheel in turn and check the discs.
But your car has been well serviced, so I'd be confident in taking it anywhere.

Originally Posted by DieselLSE

It does sound more like an interference noise than a mechanical one. I'm surprised the underbody check didn't find anything as they should have looked for something fouling the discs as Discorevy has mentioned. I'd crawl under and have a good look around at all moving parts like prop shafts and axles and then remove each wheel in turn and check the discs.
But your car has been well serviced, so I'd be confident in taking it anywhere.

Thank you.
The car has had another underbody check this morning by the RACQ Mechanic at Birdsville.
Of course the noise was not evident at the time which always makes it hard for a Mechanic!
Actually the noise is not evident when starting off, it intermittently occurs down the road a bit when everything heats up. It does not occur during short trips around town.
The Mechanic advised that, after checking on a hoist, he cannot find any faults including drive shafts, rubber boots, brakes, exhaust hangers etc.
Thanks very much for the advice from all and your advice gives us confidence to keep going as planned but we will monitor and review at Marree. I have previously been crawling under the car and have taken the front wheel off at Boulia and could not find any faults. But I will continue to look for maybe some small object in the brakes as suggested.
Cheers
Rod

Originally Posted by LRnsa

Thank you.
The car has had another underbody check this morning by the RACQ Mechanic at Birdsville.
Of course the noise was not evident at the time which always makes it hard for a Mechanic!
Actually the noise is not evident when starting off, it intermittently occurs down the road a bit when everything heats up. It does not occur during short trips around town.
The Mechanic advised that, after checking on a hoist, he cannot find any faults including drive shafts, rubber boots, brakes, exhaust hangers etc.
Thanks very much for the advice from all and your advice gives us confidence to keep going as planned but we will monitor and review at Marree. I have previously been crawling under the car and have taken the front wheel off at Boulia and could not find any faults. But I will continue to look for maybe some small object in the brakes as suggested.
Cheers
Rod

Did you check the brake caliper is not loose?
Might be worth a check.
Certainly a mechanical noise like others have said.