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View Full Version : Help! Allroad with loss of throttle



Giraffe
12-09-2007, 01:06 PM
Hi All!

I have a 2.5tdi allroad, Auto/tip transmission. Unfortunately, it seems to lose power when on an incline! (and at other times too, but is worse on hills) It sticks in one gear and doesn't always move up to the next gear (sorry to all those other drivers who I pulled out to pass, then they overtook me when the car backed off to 40 mph on the motorway!) When in cruise control mode, it even struggled to maintain the set speed and dropped right back to around 45 from 65(ish)

This is really frustrating and I have no confidence in the car for overtaking safely. Have got it booked into Edinburgh Audi for diagnostics on Monday, but just wondered whether anyone can shed any light on the subject as I really don't have much confidence in these big garages either! (being a female I always think they talk down to me - buggers!)

:Blush2:

Crasher
12-09-2007, 01:07 PM
Post the fault code report on here when you have it.

Giraffe
12-09-2007, 07:19 PM
Will do; I've also been reading some of the other threads which state faulty vacuum hoses and such like. Once I've recovered from the shock of Audi's bill, will post the fault code.

Thanks for reply!

:p

Giraffe
17-09-2007, 04:26 PM
Right, have been to Audi and low and behold, I need a new air mass meter. Don't believe them as they tried this on another Audi I had years ago and it didn't do any good!

Also noted the next fault which seems more likely to me (what do I know - I'm a woman!); :D

Engine Electronics - (00575) Intake manifold pressure - value below lower control limit, sporadic fault
X Turbocharger adjuster mechanism

Any comments....?

Crasher
18-09-2007, 11:03 AM
Classic fault code for jammed turbo vanes which is a very big problem on the 2.5 V6 TDI BUT a new AFM can give a similar result and the 2.5 V6 TDI is prone to loosing power due to a faulty ECU.

Giraffe
18-09-2007, 12:55 PM
Okay... so I should change the AMM?? I'm thinking that it's a 'plug & play' part and should be able to change it myself??

When you say vanes, do you mean the hoses?? (remember I am female!) :Blush2:

Incidentally, I've noticed today and yesterday that when I drive in the manual mode, I feel that the car goes much better. It does still play up, but not nearly so much... Is this just my imagination???

Thanks

Crasher
18-09-2007, 01:27 PM
The AMM is plug and play but only buy it from an Audi dealer, ignore any other supplier offering the part. It should cost you £95.92 inc. VAT plus the surcharge which is refundable when you return the old unit. By driving in manual you will be keeping the revs higher and the turbo at higher speed. By vanes, I mean, well, vanes-as that’s what they are. They guide the exhaust gases inside the turbo at different speeds so altering the way the turbo produces boost. Google “Variable Nozzle Turbine” to see what I mean about vanes.

Giraffe
18-09-2007, 06:35 PM
Thanks, Edinburgh Audi quoted £80 +vat so that's where I'm gonna get it from. Will order tonight or tomorrow so it should be here by the end of the week. Will let you know how I get on.

Can't wait to get it sorted as I'm struggling to average 30mpg just now and it's all motorway driving I do.

My 1.8T passat estate did nearly 40mpg! Maybe should go back to VW?????

Thanks again for your input - I really appreciate it! :biglaugh:

GFMALAN
20-09-2007, 02:49 PM
Here is a link on the inside of a turbo, the last picture will show you the vanes that adjust, and in some cases get "sticky" and then you have it...
http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/body_vnt15-turbo.html

Giraffe
20-09-2007, 05:55 PM
Thanks! I have a better idea with the pics.

Have now changed the AMM and guess what....? no change!

What's next? These vanes? This seems a bit adventurous for the likes of us mere mortals!

I reckon I'll just have to book it in to a garage to see if anyone else can sort it. Anyone know of a good garage Edinburgh/Lothians/North East???????

:aargh4:

GFMALAN
20-09-2007, 08:20 PM
I think there is still atleast one thing that you can do before worring about the vanes. If you use VAG software to cycle the n75 valvue then you can also check if the acutator on the turbo move up and down. Then you ruled out the 2 valvues and the vacuum lines and the vacuum. Then it can be the turbo itself or ECU fault (highly unlikely)

Crasher
20-09-2007, 08:20 PM
If the vanes are seized, an exchange turbo is the best bet and I would recommend you buy one from Audi, no matter who fits it. They have a two year guarantee that includes labour even if someone other than Audi fits it.

Giraffe
21-09-2007, 12:55 PM
Will have a look into these this weekend.

Not sure if this is connected, but hubby was driving to work in it this morning and said the oil pressure gauge was low, then the oil light came on. Has topped it up but now unsure whether there could be a connection between the oil pressure and the fault. (?)

Have to say that this has been an education for me so far! I really appreciate the quick responses - keep 'em coming!

Crasher
21-09-2007, 01:42 PM
How much oil did he have to put in.

Giraffe
21-09-2007, 05:51 PM
Not much, apparently. (sorry can't be more precise)

It's in a local garage (someone we trust) for a service; oil/filter changes etc... Even though there was still 2500 miles left before it was due again.

Apparently, when hubby was driving it up to the garage, it went quite well in cruise mode. Didn't drop speed up hills.

D'ya think it could be linked to the pressure gauge??

Crasher
21-09-2007, 08:05 PM
It dropping oil pressure and not needing very much oil is worrying.

Giraffe
21-09-2007, 10:08 PM
Eeeek! Not what I want to hear!

He reckons around a half litre of oil was put in.

Could this be to do with the pump?

Giraffe
21-09-2007, 11:16 PM
Would the drop in pressure make the car go into limp mode and serve as a warning that the oil pump was going to pack up?? Or something along those lines?

Crasher
22-09-2007, 01:06 PM
No. What oil pressure is the gauge showing?

Giraffe
22-09-2007, 09:58 PM
It was flat - no reading at all when he noticed. Once the oil was put in, it went up a bit. Again, sorry I can't be more specific, I didn't see it.

He travels less distance than I do to work so we thought it best for me not to have to try and get it up some hills etc... I really had to boot it to try and get something out of it. I don't want to cause any damage.

I've not heard anything back from the local garage yet, so I guess I won't get it back now til Monday/Tuesday of next week. (I can live in hope) I think they're just going to service it with oil/filters etc... fair enough, it sounds too easy - but it certainly can't do any harm (other than to my funds!)

(Note to self; must keep sense of humour!)

Will update as soon as I hear anything. On looking around the internet, I found this site http://www.autohausaz.com/audi-auto-parts/audi-oil-pressure.html

It keeps it reasonably simple for me to follow.

Giraffe
23-10-2007, 06:11 PM
Okay.... been a while since I checked in with you guys, but.....

My baby works!!!!!!!!!!!

Was in the garage for ages... but def worth it as it's come back and is going like a train :D

The things that needed done were an egr valve and something else (not sure what it's called so have put the part nos below!)

059 906 627 A (says converter on it)
059 131 503 (says valve, so I guess this is the EGR??)

Wanted to know how much these parts were out of interest. Anyone know???

Anyway, feel like lady muck driving about now!!!

V V V V HAPPY! Def recommend this garage based near Sighthill Edinburgh

Crasher
23-10-2007, 09:41 PM
The EGR valve and its control solenoid, very common failures on the 2.5TDI. Glad it is sorted.