HELP: EGR valve noise on TDI75???

A7YJJ

A7YJJ

Member
Hi all, well I'm now experiencing the annoying 'drone' or 'mooing' sound on my TDI75. The noise is only there at low revs/on light throttle etc etc. Does anyone know how/where this can be fixed, at reasonable cost? I don't really want to take the car to an Audi Dealer, but the car is booked in at Audi PRESTON while I consider my options. Can the EGR valve be cleaned and/or related pipping tied up somehow, to reduce the noise/vibration? Apart from the noise, engine performance is excellent. Car has FASH, is still under Audi warranty (is this a warranty job?).

Thanks for your help
 
i think im suffering this mooing sound just when you lift the clutch and accelerate past the biting point.

i checked out the link above but is there a step by step instruction, video or pictures telling you how this is done?

cheers

cammy
 
Nope
Everytime I have enquired re EGR valve threads I have just hit a brick wall or been told to get a remap by various members here, not particularly helpful if you just want to clean the EGR valve..
I did post a thread a few months back with a link back to the VW T5 forum where there were pics and instructions on how to remove clean the EGR and replace, unfortunately different make and engine probably makes that how to useless to us A2 owners!
 
so that being said crazylegs...does any moderators have any insight into this???

i know my car has been remapped (done by last owner) and with it seems to have created more problems just for a simple bhp increase consisting of a 3rd gear crunch and a mooing sound :(

does anyone know if a remap to original settings will cure this?

cammy
 
Mr Angry said:
i think im suffering this mooing sound just when you lift the clutch and accelerate past the biting point.

i checked out the link above but is there a step by step instruction, video or pictures telling you how this is done?

cheers

cammy
Click to expand...

mooing noise present on mine simply by tapping the accelerator, when I first started hearing the noise I had it as either clutch or suspension issue until forum searches proved otherwise, I have learned to live with it.

try bringing sound up without use of clutch, as we could be looking at a different issue.
 
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Crazylegs said:
Who remapped it as most normally remap the EGR out at the same time which should stop any noises
Click to expand...
no idea crazylegs, will need to contact last owner and see :)

lets hope someone does a diy video/pictures of a stripdown and rebuild :)

cammy
 
The mooing is caused by a vibration in the valve assembly resonating at certain frequencies. There is a "fix" which basically adds some damping to stop the vibrations, but it'll never get rid of it completely.
Cammy, if your car has been remapped, the EGR will be disabled, but it may still vibrate. As to the 3rd gear crunching, you can't necessarily blame that on the remap either - the 3rd/4th gear synchro sleeve is a known weakness in these gearboxes; Audi recognised that and the later models have beefed up design.
 
dan_b said:
As to the 3rd gear crunching, you can't necessarily blame that on the remap either - the 3rd/4th gear synchro sleeve is a known weakness in these gearboxes; Audi recognised that and the later models have beefed up design.
Click to expand...

yea ive also been told this too but the last owner told me this happened after the remap was done or maybe it was just a coincidence!

regarding the fix for the egr...is there a step by step guide?

cammy
 
Agree. The torque that the 75TDi remap puts out is still within the upper margin of what the gearbox and clutch is rated to so I'd say it's simply the weak (ie. poor design) of the synchro. I had my synchro replaced last year along with the clutch at 140k miles, it had been getting slowly but steadily worse and I decided I'd do something about it.
 
I think the N75 is the wastegate actuator, not the EGR, but the links for isolator bobbins and procedure are all for the EGR don't worry :)
 
Thanks for all your feedback. Well, it seems to me this problem can only be cured completely by cleaning or replacing the EGR valve assembly (a completely new valve is probably the best option). Has anyone had this work done at Audi or a reputable dealer? Cost of OE parts and labour?
 
I suspect that the 'mooing' is caused by the valve not being able to close completely because of a build-up of crud! Long ago I was involved in testing the steam tightness of the piston valves of a large restored GWR loco. It involved placing the loco in such a position that all four piston valves were closed, putting the brakes full on and opening the regulator. The steam blowing past the valves sounded like a church organ!

RAB
 
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UPDATE: Hi all, just to update you on my 'EGR' fault. Well, I took the car to Audi PRESTON - they have some very thorough engineers up there, and have been looking after my A2 for a while. Within hours they'd traced the problem to a faulty Alternator Free Wheel Pully, which had seized, combined with a badly worn auxiliary belt. Car was repaired under the Audi extended warranty. The noise has now gone. As a side issue, when I went to pick up the car, it had been thoroughly vacuumed and given such a good wash I thought it had been polished! Perhaps they have a high quality jet wash, but their customer service is excellent overall.
 
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