Hello lads and lasses im knew here, I would like to give a bit of back story before Im given the much needed help im after, so bare with me and this long thread.

My dad and I own a audi a4 1999 1.9 tdi ( 81kw/ 110 hp ) , and when we first got drove it, it would not go over 40 mph ( foot flat to floor ), we then learned that this was due to over boosting and ended up changing the relevant MAF sensor and managed to get to 60 and beond , but the car still felt like it was lagging.

After this we then discovered that there was massive amounts of oil in the cooling system as in, thick crude black oil in the over flow tank and dreaded the worst. ( cracked head ) A garage said it could possibly be that its cracked OR that it was the oil cooler that was causing the issue, thankfully it was the latter. Since disconnecting the oil cooler, and flushing the system several times it now runs clear and the temperatures are sane again. ( all the oil in water diden't help to cool )

Which leads to the next problem, the car accelerates and can get to 80+ on the motorway , but it takes it's sweet time in doing so. Before this however when it struggled to get more than 65, I had a look under the bonnet and noticed several of the vacuum pipes where off and I reconnected them accordingly to what I thought was right and for a day or so it was absolutely brilliant , 0-60 in about 7-8 seconds flat out. Now however its foot to the floor nearly just to get to 60, it will go higher but the pedal needs to be depressed and held there, not like before where I could just touch it and be off.

So thats that, a mouth full I know. Im thinking my sudden lack of power is do either do with another faulty sensor, since there about 5 of them or there is a leak in the vacuum system. If I remove the MAF sensor connector and take it for a spin, it won't go past 40 foot flat out.. so i guess that one is ok.

A final thing worth mentioning is that the engine sort of " growls " and not purrs like it used to when it was " absolutely brilliant " , so maybe I have the vacuum pot pipes or the turbo's actuator pipe the wrong way round ?

If someone could give me some advice id' appreciate it.

 

Just a note, most people on here are from 'Murica and we never got that engine in a B5 over here. However, we did get it in Jett'as, and I had one before.

Actually, my symptoms were very similar to yours. Took me a while, but I figured out the MAF was bad. After that, it would finally move.

However, the vanes in the tubro were not operating very well, so I would check into that. And this is of course assuming audi's have a similar variable vane turbo like the jetta did

 

Cheers for the info appreciate it , the B5 does have the same turbo vanes as the jetta or very similar.

MAF has been changed a few times so I don't think it's that , I know there are other sensors too but seems a little suspect that their dead also.

I think the issue is the vacuum pipes.. the only trouble is finding the leak.

 

The third generation VW's Jetta 1.9 TDI is virtually the same as the audi's first generation post-face lift series, so I would assume the vanes are identical nearly or very close so i'll look into getting them cleaned.

 

Yeah get the vanes cleaned out. I can almost promise you they are carboned up BAD. Also, look into the intake manifold. Those too are known for massive amounts of carbon deposits.