The infamous audi a4 pull back problem, or not.

[sammydfp36]

Hello lads and lass im knew here, not sure if this is the right section to post for this but im pretty sure the a4 had 4 wheels last time i checked, bit of back story before we begin.

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.

[Sam]

Hello lads and lass im knew here, not sure if this is the right section to post for this but im pretty sure the a4 had 4 wheels last time i checked, bit of back story before we begin.

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Thread moved to A4 B5 section.

[sammydfp36]

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Close but...

Thread moved to A4 B5 section.

Ahh sorry bout that mod, diden't see the class specific zone hopefully I can get the help I need here.

[leighmagill]

Check the vacuum hoses first, replace with silicone, only costs a few £. Then I'd look at cleaning the variable vanes of the turbo. I did this with oven cleaner. Search on here, I wrote a thread on it.

[sammydfp36]

Sorry for the delay was looking into the problem.

So I've done as advised and replaced the pipe from the actuator which should of been nice and solid as it was a vacuum pipe, but it litteraly fell to pieces in my hand. Also it had several pinprick holes along it's length and I think I will replace all the other pipes to and from the sensors as they look in similar condition.

Now a question if I may : What is the purpose of the valve which sits atop the rocker cover ? I think it's called the PCV valve, the reason I ask this is upon looking at it's joining pipe there is gaping hole in the pipe that connects the PCV to a small "filter " type pot, since this is linked to the air system I take it , it won't do any good.

For now I have just put tape around it till I can identify what it is and where I can get a part and it definetly feels like it pulls better. Beforehand I left out a important detail about the cars performance, I can accelerate to 60 and beyond in 3rd with no issue currently it's 0-60 flat out in about 9-10 seconds , better but not as good as it was. ( 7 seconds ) However when I stick it in 4th to roar off at mid speeds it just laughs at me.. so this HAS to be a boost problem caused by vacuum ? - lol well lack of vacuum *

A last note, having looking at the leak of rail pipes, their frayed and look a bit dubious.. but I can't smell any diesel so I guess they are ok ?

Cheers.