Strange noise ....any ideas ?

M

mycxc00

Member
hi....Ive just recently bought a Audi A2 1.4TDI se privately. All appears to be ok with the car apart from a strange noise coming from the engine at the passengers side. Its hard to explain what is sounds like but the best I can say is it like a deep bass sound. It only make the sound at low revs (below 15000 in either 1st or 2nd gear. No warning lights are on the dash board....Has anyone got any ideas as to what it may be.
 
This would be the noise that Tonbridge Audi claimed had never heard of before, would it? The same one that has it's own chapter in the VAG workshop manuals..... ;)

We had the modification done - not by Tonbridge Audi, funnily enough - improved the noise but didn't eradicate it completely.
 
Noy sure the noise is a mooing sound. Its like a deep base sound and only does it at low revs. If im crawling in city traffic and I let the clutch out and apply a few revs I get like a couple of deep muffled bassey sounds from the passengers side of the engine. Ive looked on the forum and it would appear that most think its a EGR valve problem....
 
Don't worry T7RSE, when the weather warms up it probably will start to moo! I have a Sport and my cow seems to go somwhere warmer for the cold English winter!
 
I've just bought a 1.4tdi se from an independant dealer, its got 5 months left on the warranty - noticed the noise since its been a bit warmer. Is it ok to leave without getting it fixed? Or will soemthing expensive go wrong if I don't get it sorted? Only the dealer is 100 miles away from me so I only want to get it sorted if its a serious problem - I can live with the noise if its not serious.

Cheers
 
Hi robberts1, welcome to the A2oc
The EGR valve is used to reduce NOX emissions under specific load conditions. It does this by recirculating exhaust gas back into the combustion chambers. This reduces the ammount of fresh air available for the combustion, causing a cooler (less efficient) burn. I've never heard of this happening but the only bad thing which could go wrong with the EGR valve is for it to stick open and continually allow exhaust back into the intake manifold, permanently reducing engine efficiency. It can also coke up the intake manifold as the hot exhaust gas carbons up the oil mist from the engine breather system (which is also fed back into the air intake manifold)
I know some people who have disconnected and blanked off the vacuum pipe to the valve so it never works.
What was your question - oh yes, if you don't bother getting it checked its very unlikely to develop into an expensive problem. However, as you have a warranty you may as well have the benefit of it so my suggestion would be to report it to the dealer (in writing) and let them decide.

Cheers Spike
 
Yep....that is definitely the EGR valve. It used to happen in mine when I was stuck in heavy nose2tail traffic for 30min+ of stop/start driving - think of the M6 at Birmingham!

However the A2 used to go on 400+ mile runs every month along the motorway and other than above never noticed it at other times. I now drive a Treg - but got my mind set on another A2 at the end of the year!
 
My car seems to have caught mad cow disease too! I'm getting a constant hum/oooing type noise from the front passenger side. I first noticed in the summer when stuck on the dreaded M6/M5, and although it happened once or twice since after a long trip it's been fine until now. The noise is fainter but present from start up and idle, the noise fluctuates momentarily when I touch the throttle or move off but is there at all speeds. Could this be the ERG valve or a loose vacuum pipe? I thought the problem only affected earlier diesels? Anyway, does anyone know how to locate the valve/ vacuum pipe?
Could this also explain an increase in fuel consumption. I'm only getting 51 mpg with mostly 70mph motorway driving?

Any ideas? If I need a new valve does anyone know how expensive the part is and whether it's a DIY job?

Thanks,
Simon
 
SimonT said:
Any ideas? If I need a new valve does anyone know how expensive the part is and whether it's a DIY job?
Click to expand...

Here's a quick and no-cost solution. Mine mooed away like it was milking time in the parlour, usually on very light throttle (the car, not the cow!). Previous posts are correct - it is the egr valve. The main fault is that it is hard-mounted by two studs/nuts (10mm) on the bulkhead underneath the passenger-side dashboard area. This provide a resonant surface of which Stradivarius would have been proud.

There is no real need for it to be fixed in this way. Unless you want to pay for an Audi aftermarket fix (I believe they have some sort of rubber isolation mount/adapter?) then just undo the two nuts and let it hang. It has enough vacuum pipes etc. going to it to self-support. If you're in any doubt you can always cable-tie it to the more secure hoses/cables nearby.

I've done mine and the mooing has gone entirely. When stationary on the driveway, with the bonnet off and door open I can hear a very faint noise - but it's much more like a dog's "ruff" now:D!
 
dilbert, any chance of a photo to show us all your success.
Where exactly is the position of the mounting for the pipe?
ta, hopefuly I will lose the damn cow once and for all!
Glen
 
dilbert, no need for photo, had another look on ELSA and found the 'quacking' technical solution which shows what to undo.
I was looking at the rear of the EGR itself (after removing the insulation cover over the engine) rather than right in front of me.
Have undone the two nuts and suspended the pipework bracket to one of the cooling pipes
see what happens
Glen
 
Mooing, Quacking and oohing is no more!

It works!
No cost, easy solution, and the noises have finally gone!
Glen
 
Glen,

Sorry about no reply - been away from the PC for a couple of days. Pleased that you managed to sort it.

dilbert
 
dilbert said:
Here's a quick and no-cost solution. Mine mooed away like it was milking time in the parlour, usually on very light throttle (the car, not the cow!). Previous posts are correct - it is the egr valve. The main fault is that it is hard-mounted by two studs/nuts (10mm) on the bulkhead underneath the passenger-side dashboard area. This provide a resonant surface of which Stradivarius would have been proud.

There is no real need for it to be fixed in this way. Unless you want to pay for an Audi aftermarket fix (I believe they have some sort of rubber isolation mount/adapter?) then just undo the two nuts and let it hang. It has enough vacuum pipes etc. going to it to self-support. If you're in any doubt you can always cable-tie it to the more secure hoses/cables nearby.

I've done mine and the mooing has gone entirely. When stationary on the driveway, with the bonnet off and door open I can hear a very faint noise - but it's much more like a dog's "ruff" now:D!
Click to expand...

mines been making a nose in gear when you push to 1.5k rpm and goes once on 2k reves and yes it is a "moo moo" i was told it was a gear box mounting £150 later still " moo" now when they sqeeze a air hose on the right of the air intake attached to vaccum pump same noise.
I was told it needs a vac pump £400 + labour. I went to audi to see if pump avaliable. Told never had to sell one must be something else.

I visited this forum looking for vaccum pump and this read thread and i must say this sounds like my fault exactly

Is this the EGR and where are these bolts ?? please please -pics would be dearly appreicated

azz
 
Have sent Azz a photo in response on a PM but include the photo here for anybody else.

I promise myself one day that I'll get around to making a proper rubber mount that uses the existing mounting studs. It's on my five year plan.
 
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