Power problems with Audi A4 Tdi - Can anyone help?

daveg

Has anyone any idea's what could be wrong with my car? It's a 2002 audi A4 Tdi. I only bought her about 3 weeks ago. Started off, on occasions, she was very sluggish and intermittently I would loose power. I previously had a VW golf with a very similar problem which turned out to be a sensor to the airflow meter. Took it out to the garage at the weekend and he replaced the sensor and all seemed well. I have still felt she was a bit sluggish (when you put the foot to the floor it take 1-2 secs before power kicks in). She is the 115bph btw.

Then this morning I had serious problems. She started fine and I got about a mile down the road when I started to loose power. I could not get the revs up at all so I pulled into the side of the road and turned the car off. I restarted and tried to go again. No power again and she conked out. She did this another few times and I eventually got moving by taking it really easy building up speed. There was also a strange sound from the engine when I started to loose power. I just made it into work. There is a steep hill before work which I nearly didn't make it up. I had to keep her in 2nd & 3rd and kept the revs as high as I could.

Any idea's? Could it be the turbo or would that only kick in at high revs?

BTW if I drop it out to the garage (again) which is about 40 miles away would it be out of order to ask for a replacement car while he fixes it? I'll be really stuck if it take him a few days.

Thanks in advance.

Big Nelly

daveg wrote:

Any idea's? Could it be the turbo or would that only kick in at high revs?

BTW if I drop it out to the garage (again) which is about 40 miles away would it be out of order to ask for a replacement car while he fixes it? I'll be really stuck if it take him a few days.

Thanks in advance.

Off the top of my head sounds like the turbo is f**ked!! what is smoke like coming out of it? have busted turbo in a jeep(Izuzu) and a van(peugeot) and both times have had similiar problems to what you say but one thing was it was blowing out smoke like a mad thing!!!

In regards to the garage!!! I would bring car back and throw it at them!!! if they had done a proper service on car before you bought it then they surely would have noticed the turbo was f**ked on it!! name and shame the garage!!!!

Wibbs

It could be the turbo, but the problems you describe sounds different as you said it wouldn't rev for you. Even if the turbo was screwed it should still rev unless the turbo completely seized, in which case it may impede the exhaust gases. You would have huge amounts of smoke in that case as Big Nelly has said.

The 1/2 secs you say it takes to develop power could simply be turbo lag. Turbos are driven off the exhaust gasses and as such take time to spool up and give you the "kick".

It sounds more like a fuelling problem to me, but that covers a multitude of sins.

Big Nelly

Wibbs wrote:

It could be the turbo, but the problems you describe sounds different as you said it wouldn't rev for you. Even if the turbo was screwed it should still rev unless the turbo completely seized, in which case it may impede the exhaust gases. You would have huge amounts of smoke in that case as Big Nelly has said.

The 1/2 secs you say it takes to develop power could simply be turbo lag. Turbos are driven off the exhaust gasses and as such take time to spool up and give you the "kick".

It sounds more like a fuelling problem to me, but that covers a multitude of sins.

Not sure what you mean by fueling problems? had problem before where the diesel wasnt getting to the engine but the car would just chuck a few times and then die.....wouldnt lose power or anything....would just cut out......same as if you are too cheap to fill the tank and the car cuts out :eek:

Wouldnt see a problem with Turbo lad on the A4.....driving a 98 A4 this week while I left Passat in garage for checkup before 6 mont warrenty is gone and althou the cars are more or less the same there seems to be a little more kick in the A4.....the 02 115Bhp should be alot quicker as well......I still go with Turbo problem from the previous problem he had with motor!! could be wrong but thats my opinion!! shoot me if Im wrong! anyway if you find out just in case it something similiar happens to anyone else!!!

kluivert

Something is wrong with the air flow.

Throttle body maybe full of carbon deposits and needs cleaning badly.

Something stuck it the air in take.

To check the turbo - get the garage to check it out. The bearings may need to be replaced.

If the garage is an Audi Dealership they should give you a replacement no bother if it takes a couple of days to fix it.

Audi 1.9 TDI - nice car.

daveg

Lads,

Thanks for the replies so far. I did not buy from an Audi dealership. The guy has a small scale garage but gave 3 months parts and labour.

One of the lads has a laptop and diagnostic software at work. He checked it out briefly today and is of the opinion a solenoid is faulty. From what I understand this varies the air flow into the engine. He is thinking along the same lines as you Klivert.

He didn't think it was the turbo and to answer your questions there is no irregular emissions.

My mate is going to run the full diagnostic this evening or on Saturday. I think he can test each solenoid individually so he might be able to isolate the problem.

This is a pain after I bought the car only 3 weeks ago.

Thanks for the help lads.

Big Nelly

daveg wrote:

One of the lads has a laptop and diagnostic software at work. He checked it out briefly today and is of the opinion a solenoid is faulty. From what I understand this varies the air flow into the engine. He is thinking along the same lines as you Klivert

ANy idea what the software is and where you can get? will it work on a Passat? someone was telling me to get this but wasnt sure what is was and how it works??? could use on bro's audi as well!!

Good luck with getting car fixed anyway!!

daveg

Big Nelly wrote:

ANy idea what the software is and where you can get? will it work on a Passat? someone was telling me to get this but wasnt sure what is was and how it works??? could use on bro's audi as well!!

Good luck with getting car fixed anyway!!

I know it's German but I can check the details later and post back. BSI or something he said earlier.

Big Nelly

daveg wrote:

I know it's German but I can check the details later and post back. BSI or something he said earlier.

Thanks!

murphaph

daveg wrote:

One of the lads has a laptop and diagnostic software at work. He checked it out briefly today and is of the opinion a solenoid is faulty. From what I understand this varies the air flow into the engine.

Sounds like the 'infamous' N75 valve. Well known troublespot on VW TDIs. From TDI Club

- Turbo boost control solenoid valve problems - this is also known as the N75 valve. If you have VAG-COM, and a trouble code of "intake manifold pressure control" is being set, and the problem is NOT a sticky VNT mechanism (see above), the N75 valve may be sticking, clogged with debris, or faulty. It can be removed from the vehicle and the paths through the valve checked by blowing through the various connections with the valve first de-energized, and then energized with 12 volts. Alternatively, obtain a vacuum gauge and "T" it into the hose that goes from the N75 valve to the VNT vacuum diaphragm, and confirm that the vacuum varies under different load conditions while driving. If found to be faulty, some have had success by blowing solvent through the valve to remove any deposits, but replacement with a new one may be the best option.

The software is called VAG-COM. It's produced by Ross-Tech and as a user I'd highly recommend it to any VW/Audi/Seat/Skoda of recent enough vintage owner.

Big Nelly

murphaph wrote:

The software is called VAG-COM. It's produced by Ross-Tech and as a user I'd highly recommend it to any VW/Audi/Seat/Skoda of recent enough vintage owner.

is there anywhere you can buy this in Ireland? or you know anyone selling....bit steep to buy from them!! seen a few places on ebay for about 20 quid but couldnt thrust them!!

Edit....just seen the free download...is this any good? also the cables you get from ebay for about 16 quid are the ones are they?

murphaph

Big Nelly wrote:

is there anywhere you can buy this in Ireland? or you know anyone selling....bit steep to buy from them!! seen a few places on ebay for about 20 quid but couldnt thrust them!!

Edit....just seen the free download...is this any good? also the cables you get from ebay for about 16 quid are the ones are they?

I can't really say-I bought the registered software and cables from Ross-tech when Uwe Ross initially started up years ago so it was only $99 with free software updates for life. He puts a hell of a lot of work into reverse engineering the VW protocols and I think he's charging a reasonable amount (esp compared to similar setups which charge thousands!). The customer service is excellent too-they'll do whatever they can to help with a problem car etc.

The free download will display all troble codes but will not be able to do a lot of the recoding stuff. The trouble codes still need to be deciphered, but there are a lot of internet resources for that even if you don't have a manual to reference against. A google with the code often throws up the solution. The full version will decode the code into english.

Big Nelly

murphaph wrote:

I can't really say-I bought the registered software and cables from Ross-tech when Uwe Ross initially started up years ago so it was only $99 with free software updates for life. He puts a hell of a lot of work into reverse engineering the VW protocols and I think he's charging a reasonable amount (esp compared to similar setups which charge thousands!). The customer service is excellent too-they'll do whatever they can to help with a problem car etc.

The free download will display all troble codes but will not be able to do a lot of the recoding stuff. The trouble codes still need to be deciphered, but there are a lot of internet resources for that even if you don't have a manual to reference against. A google with the code often throws up the solution. The full version will decode the code into english.

Well there is a software license for 99 but I guess you would need to buy cable then and get the software itself.....going to emaill them anyway......could be usefull cause bro and girlfiend have Audi's and me and other bro have Passats.....spilt cost maybe!!

Sorry for jumping on your thread daveg!!