04 TDI....help needed!

[white_lightning]

I am loosing power and the emmisions warning light is on. The power is usually ok when i start the car but the more I drive the worse it gets. The turbo is also there at the start but once the car goes into a sort of limp mode, even with my foot to the ground i get little power. This problem is most noticable when I go on the motorway. After I reach about 65mph something sorts of cuts out and I can barely keep up with HGV's especially on hills.

I replace the Air Flow Meter but no joy so I took it to the dreaded local dealer where they diagnosed it was an N75(wastegate bypass regulator valve) I got this replaced to the sum of £90 but it has not cured the problem with VW saying that it is unfortunate and will have to try something else......

I cant keep shelling out good cash on parts that might not be broken or might cure the problem.

Any suggestions or help please .................................

[white_lightning]

Can anyone help?

I know other users had similar problems but not alot of people mentioned what was causing there problems after they got there car repaired.

[stevegrass777]

Well it could be the turbo not operating properly. The turbo is variable boost and the valve that operates this could be sticking.
Also have you replaced the fuel filter as if this is blocked it will starve the engine of fuel.
i believe there are more than one n75 valve and they are cheap from anywhere but vw! see link.
https://sslrelay.com/s74326199.onean...dex.shopscript
really you need someone with vag com to diagnose and do an output test on some of these part's..
What area do you live and what car / engine is this . pd 1z avb
age of the car?

[GFMALAN]

Hi, White Lightning,

Was this ever sorted?
Sounds like my problem, and most things point to sticky vanes...

[chrisvrscrx]

This happened to my car shortly after the turbo blew! what is the millage? Is there any noise coming from the turbo??

[GFMALAN]

Mine 206 000km, there is a slight whistle for thepast 50 000km, but nothing other than that!

My car drives the past month as if there is no turbo,
Sometimes when driving, it is as my turbo kicks in but only between robots, then i have a normal 1.9Di (T missing!)

[chrisvrscrx]

Mine had a whistle too. When you first start it in the morning run round to the rear and see if there is quite alot of smoke coming out for 30 sec or so. This indicates to me that is is buring the oil from the failed turbo (if it is failed!!) If the engine starts to run away with its self (while driving producing white smoke) and you can't turn it off stall it straight away (stop and put it in 5th gear and apply ther brake). This means the engine is running off the oil from the turbo. This happenened to me and if you don't stop the engine it will self desruct.

I dont want to scare you but just preparing you for the worst. Let us know how you get on.

[chrisvrscrx]

https://www.vwaudiforum.co.uk/forum/s...ead.php?t=9209



This is what happened to mine.

[GFMALAN]

I don't think thats going to happen to mine....

My car never smokes, not even when put pedal to the metal, my problem stated when i was pulling away at traffic light and in 3rd or 4th gear then it is if there was a slight dead spot, and then the boost continues, this happend twice in one week, then it got worse and in the beginning it helped to reset the ECu in the driving, but then according to the forum, maybe th MAF was faulty... I've started by cleaning, and the replacing the MAF, then still nothing. Sometimes it will boost sometimes not, the past month it is like i drive 1.9 without turbo, it doesn't go into limp often, and sometime when i'm lucky it works for one minute or so.. I did replace the hoses (vacuum) just because.. but that was the only thing that looked funny.

VAG software say i have a overboost, I also tested the n75 valvue and the other one for egr (n8 something) both work and the vacuum is there when neede, I can cycle the acutator on the turbo. If i do it with my hand it is a bit stiff at some point (the beginning and end, but in the middle its fine)

2 weeks ago I removed the turbo (nearlly) but only the bottom oil pipe was still attached, then I had to reassemble everything because i needed my car. Bummer...

I really out of a technical perspective say that stickey vanes cause my problems, the only way i can find out is by cleaning/opening and see, but i'll do that on a day i feel like getting dirty again..

my compressor wheel/blades inside look clean and spins easy with no tollerance, and the overboost tells me it has something todo with the vanes and not the blades ect.

Here is a very cool article to clean the turbo as stickey vanes seems to be a freq. problem. http://www.technologie-entwicklung.d...t15-turbo.html

Hope it help someone, I'll post my answer asap... I feel like getting dirty +- Saturday this week, hope the weather permits!