Intermittent Metallic sound when driving.

[Stesaw]

So guys recently on a drive back from t' norf I started hearing this sound coming from the back of the van best described as metal rotating and rubbing against each other. I've noted it can do it on engine load and off load when you are just coasting in gear, however if you take it out of gear and coast it seems to mostly go away. Now the engine itself doesn't seem to be making the noise when running it stationary it seems to be OK even at high RPM.
Last week I changed the gearbox oil to the correct stuff and redid the drain plug as it was leaking, I thought maybe as the box was leaking it could have been something with the gearbox and I wasn't sure how much oil was left in it, so draining and filling it wouldn't hurt it.
However with the plug sorted and no more leaks with the correct oil, the noise still persists.

The problem I am having is trying to locate the noise as it's pretty difficult to be at the back of the van and driving it at the same time! Now it doesn't do it all the time, sometimes it can be very profound and sometimes just a very very quiet rubbing noise and then sometimes not even a peep out of it.
My thoughts are with what info I have to go on and limited knowledge is it could it be a bearing of sorts giving out maybe wheel or CV joint? or maybe something to do with the flywheel or clutch? judging by when it happens although if it was a wheel bearing giving out I'd expect to hear it all the time...

I am going to be changing the engine oil and filter sometime this week so I can see the condition of that and hopefully I won't find chunks of metal in it...

Any input or thoughts would be appreciated.

[Mocki]

could it be rear brakes, shoes or drums ??

[937carrera]

could it be rear brakes, shoes or drums ??

My thoughts too - drums on backplates

I suppose we should ask the obvious questions, roadspeed related or engine speed. Worse on left hand or right hand turns ?

[DoubleOSeven]

Does it go away when you brake? My first thought if it does would be wheel bearings. Easy check, jack up, grab wheel top and bottom and see if there is any movement. Quick fix would be to tighten the 46mm nut, but ideally swap bearings out. Also have a nose around while you are there to see if you’ve got any meat left on the brake shoes. The fact it’s a rotating noise points to one of these in my opinion.

[Stesaw]

I will go for a drive and see if the noise goes away when braking. To look at the drums and pads I will have to take the van to a garage for them to loosen the wheel nuts as I couldn't get em loose, even with some penetrating oil and breaker bar with some gentle jumping up and down on it.....

[Stesaw]

Went for a drive braking doesn't make it stop/start. Cornering doesn't make any difference either, it can happen on a flat straight.
Roadspeed doesn't make a difference either.
Tomorrow I'll be jacking up the rear and checking for any wobble on the wheels and to see if i can reproduce the noise.

[937carrera]

If roadspeed makes no difference then it's not wheels, brakes or driveshafts, just something moving around due to jolts or vibration

[jrt]

Put a phone video /audio up here or on the fb page
David.

[MartinR]

Few months ago took the wife's T4 to the garage for service and MOT before going off on holiday. On the way to the garage developed an awful clonking noise, on cornering, braking, accelerating (well not much on accelerating, it is an aged AAB - we call it the new van - 1993 - says it all!)

After much consideration, both by me and the garage man, realised that the missus might have started packing for our hols. Amazing how many variations on "clonk" a couple of baked bean tins loose in a cupboard can make!

Hope your rattle is equally harmless

Good luck

Martin

[Stesaw]

I think I mighta sussed it. I had a good look under the van today, a couple of cooling pipes were knocking against each other so I cut and fitted a bit of old rubber hose to one of them so they don't clang together, also secured them a bit better than they were to stop any excessive movement.
I also found this

exhaust clamp at the back that was buried away behind the engine bar had rusted away to the point where it was free on the pipe, swapped that out.
After all that I gave the whole thing a good shake to make sure there was nothing catching or loose hoping I'd sorted it....

Found that part of the exhaust needs either re-welding or replacing as the pipe is not attached to the connector/flange? and it making a fair bit of noise when I shake it. Not only that the muffler bracket is snapped as you can see in the picture but that doesn't move around at all, probably still not ideal but eh.

Also that engine bar looks horrific so I'll probably take it off at somepoint and clean/paint it.

[Mocki]

I think I mighta sussed it.
I also found this

That there clamp on the picture is a mikalaw clamp, for water pipes , a tougher version of a jubilee clip , and not a exhaust clamp ... if that was on your exhaust, bodgery has taken place in the past !

[937carrera]

High quality bodgery..........Mikalor clamps are very good for keeping turbo hoses in place when running extra boost.

That has been there a very long time

[Stesaw]

Only the hightest quality bodges on this van

But on a serious note, the exhaust system does not look stock (From all the pictures i've seen on Brickwerks / JK etc, other shops available yadda yadda ) so if I had to replace that piece of exhaust then I'd assume it's a whole new system as it wouldn't fit the exsisting parts. oof.
The question is, as my van is a 1985, would I have to get the early exhaust kit or the late one? I assume late as the water pump / coolant system seems to be of the late type, but as I am finding this might not be such a clear cut case.

[ash1293]

Looks like the blow on the exhaust has been bodged with high temp silicone then the clamp over it.

Not sure if it will weld in situ, but if it’s solid enough you may get a couple of tack welds on it before attempting to remove to maintain alignment. If not couple of marks would do.

If head exhaust studs are clean you may get lucky in removal. Really good clean up and I reckon it would weld as it appears to have gone at a weld rather than rotted through.


Sent from my iPhone using Tapatalk

[ash1293]

Looks like an Empi quiet pack exhaust from that angle but I could be wrong.

Early system I believe, certainly not late.


Sent from my iPhone using Tapatalk