Random Rattling / buzzing noise (video)

[Jonwm]

Morning All

Appreciate the vans all rattle (well mine does!!) but this is a bit different, over the last month my van has developed a weird rattle / buzzing noise that comes from the centre of the dash by the bulkhead, at first I thought it was something that had slipped down, it wasn't unfortunately, I've been monitoring it over the last few weeks and it seems to be only when the van is well up to temperature and under lighter load, its only between 1.7k and 2.1k revs, and it more like a buzzing.

I run the van on premium fuel and had a major service at Midland VW in November, the only thing noted was that the aux belt/ tensioner was noisy, this has squeaked at start up for over a year now so kind of dismissing its this.

Van is a factory T32 Kombi 150 DSG and has done 68k

It does good runs most weeks and the noise has become more noticeable id say as I've not been using coasting mode on the gearbox so its holding revs around that mark when off the accelerator.

Not the best videos and ones a short as I held the phone the wrong way round!

Dark one here is last night after coming home after a 30 mile drive mainly motorway, you can here the buzzing as I come round the corner to the drive and when revving in to 2k

Second video is just now after a 2 mile drive to drop kids off and its not there.

Its pointing me to think it not a loose trim panel as its really consistent at those revs and situations.

I tried to look under the engine bay but my lad hasn't got the consistency to keep it at the desired revs!! but sounds lie its coming from the bullhead area, only noticeable thing is it can sound a bit gassy too at those revs like its got an air leak or a wet fart, got told they all sound like that thought!

Its had a new EGR Flexi and filters changed.

Any help / guidance appreciated, I Am getting the tensioner aux aux belt done this month but don't think its this.

If not does anyone want to buy a van as it drives me mad haha

 

[Dundee_Kev]

I'd be tapping all the heat shields to see if any have a tinny sound. Obviously don't try it with a red hot engine!

Also check everything that is clipped to the bulkhead and make sure it's all nice and tight. You'd be amazed how much noise a fuel/brake pipe can make.

 

[Jonwm]

This might sound ridiculous, but just went to check heatshield / bulkhead and could see nothing, then I saw a flash of yellow in windscreen, got a piece of carboard down there and there is a HB pencil (not mine) down the back, I checked that weeks ago too, going out on a drive in a minute so that might be the culprit, feel a right idiot if it is that!
It also begs the question where it came from, had an MOT done on it about the same time the noise started so going to blame the ATS man if it turns out it is that!!

 

[Jonwm]

Want that after all, back to the drawing board :-(

 

[Dundee_Kev]

Want that after all, back to the drawing board :-(

It's quite handy you found that pencil then!

 

[The Bear78]

Here we go with the random suggestion...
My van developed a rattle that I was chasing round the dash for ages. I was adamant that it was behind the radio but in the end it was the rectangular panel in the ceiling trim, directly below the cubby hole in the centre.
It still comes loose occasionally and now that I know what it is, it sounds like it's exactly where it is! However, at the time the noise seemed to be from the base of the windscreen and must have been reflecting off the surfaces.

 

[Paynewright]

Wasn’t there an issue on some vans with brake pipes on the bulkhead that zing at a particular engine revs?

 

[Jonwm]

Cheers gents, I did listen at the mirror and did seem to be coming from base of the windscreen, I might do some more investigation. All I can think of that has changed is the pollen filter, not sure if that can cause a buzzing vibrating if not seated properly.

Just really weird it's only when the engine is warm.

 

[Jonwm]

Thought I'd update this thread as I may have found the problem.

It seems to have been the N75 valve, there is like a filter thing on it, its was touching the bulkhead and must be either failing or rubbed any protection off, I put some tessa tape round it to see if it helps and on todays drive its gone.

If it stays silent I'll replace the valve, I get no error codes from it but thinking it could be on its way out.

 

[Jonwm]

So it wasn't that after all! Noise is back now, took it to local VW guy who said it was N75 valve failing, changed that and still the same noise. Losing my mind with it now!
Any other suggestions welcome!

 

[Jonwm]

Just thought I'd update this as I'm literally losing my mind with it and needed a tiny bit of help.

Took it to be a transporter place yesterday and they listened whilst I held the revs to produce the buzz / rattle, they felt it was from under or from the charge cooler, I've looked online and can see most of the charge coolers have a bracket at the front that bolts into the base, mine is loose, its held in by the hoses, I can lift it up about 1cm total or much more if lifting just the front or back, since messing with it ther noise has stopped, drove about 50 miles today and no noise so its pointing at this loose cooler.

Last time it was off was in VW to change a glow plug.

Has anyone got an early T6 150 with this shape cooler on to see if yours is loose, it feels like it should be bolted down, pic of of the front where on used ones there appears to be a bracket coming of it, i can lift the circled bit and it will lift as far as the hoses allow.


This is from the top, i think they changed it from 2017, it just sits there being held by the hoses.


I think this being loose is whats causing some of the vibration noise.

Any help appreciated

 

[Jonwm]

Some more googling has found a used one and it seems mines not on this plate very good with the black bung type things

Anyone know if these are replaceable

 

[bobbybasic]

Just thought I'd update this as I'm literally losing my mind with it and needed a tiny bit of help.

Took it to be a transporter place yesterday and they listened whilst I held the revs to produce the buzz / rattle, they felt it was from under or from the charge cooler, I've looked online and can see most of the charge coolers have a bracket at the front that bolts into the base, mine is loose, its held in by the hoses, I can lift it up about 1cm total or much more if lifting just the front or back, since messing with it ther noise has stopped, drove about 50 miles today and no noise so its pointing at this loose cooler.

Last time it was off was in VW to change a glow plug.

Has anyone got an early T6 150 with this shape cooler on to see if yours is loose, it feels like it should be bolted down, pic of of the front where on used ones there appears to be a bracket coming of it, i can lift the circled bit and it will lift as far as the hoses allow.
View attachment 245236

This is from the top, i think they changed it from 2017, it just sits there being held by the hoses.
View attachment 245237

I think this being loose is whats causing some of the vibration noise.

Any help appreciated

I have a 150 and my charge cooler is loose as well.

With the bonnet up and facing the engine it can be lifted from the top left corner, or if pushed down it’s metal-on-metal.

I’m temped to pop a piece of rubber in there, but I’m not sure if there’s heat in that area?

 

[bobbybasic]

Just uploaded a video I made when I first discovered it last November.

 

[bobbybasic]

Found these:

T6 EURO6 102bhp shaky charge cooler

I looked all related topics but couldn't find the answer that I'm looking for. Patient is 2017 T6 102bhp EURO6, 75k miles on the clock. Right hand side of charge intercooler is quite shaky on idle, cold or worm engine. It stops shaking above 1k rpm. How many bolts is actually fixing it? I can...

www.t6forum.com

Is this missing a bolt?

Could anyone shed any light as to wether the circled corner should have a bolt, it rattles abit when the engine is running but doesnt look like there’s been a bolt in it for a while

www.t6forum.com

 

[Jonwm]

Just uploaded a video I made when I first discovered it last November.

Exactly the same as mine, I can see a rubber grommet under there but doesn't seem to be holding the cooler in place, I can move mine sideway a little too.

Your concern on heat is mine too, I want to put something under there just to try it, my luck would be that it dropped out and caught in all the belts!!

Mine seems to be fine when cold so thinking when the rubber heats up its not protecting the metal from touching hence getting the buzzing at specific revs whether still or moving.

 

[DXX]

No wonder these plate coolers leak and dump coolant into the engine, what a incredibly crap design!

 

[Jonwm]

No wonder these plate coolers leak and dump coolant into the engine, what a incredibly crap design!

It seems these particular coolers were replaced in 2017 with ones that don't have the plate underneath, they just bolt onto the frame that's onto the engine. They must have realised the error of there ways.

 

[Jonwm]

Managed to get a rubber door wedge under the cooler tonight, same noise so not the cooler!! Gutted as thought my 7 month ordeal was solved! Genuinely can't think of anything else it can be now, must be something broken off in the back of the dash that is stuck that moves with heat.

I actually feel defeated by it, cant keep throwing money at it when its not guaranteed to solve it. appreciate all the help anyway!

 

[Jonwm]

Thought I'd update this as it seems to have sorted itself.

No one could find anything wrong with the van, took it to 3 places the last 12 months all just said it was a very strange noise, it has been getting worse of late, gave up and just thought I'd get it MOT'd and serviced and sell it with the noise! (cheaper ovs).

Anyway gets it serviced and they changed the D bushes as they were knocking and its appeared to have resolved it, not sure if the previous garage had used the incorrect oil or something or overfilled it as they said it seemed high considering 10k of use.

So i can keep it for a bit now