flat spot mk4 tdi 130

**ashatum** · 06-07-2009,10:25 AM

hello to all. i have a problem on my beloved gt 130tdi. had the car for about 18months now but in the last few months a flat spot has developed. normally you can feel the turbo comming in at about 1500rpm then really kicking in around 1800+, but now its REALLY flat until over 2000rpm. this only happens for the first 5mins or so of driving when suddenly the car is back to normal! doesnt seem to matter if the engine is hot or cold. if i leave the car to go into the shop or something and get back in then its flat again. its like a torque tug of war with my emotions lol. please help??? many thnaks
ash

**Crasher** · 06-07-2009,10:55 AM

Take it to someone with fault code reading equipment, it will probably give code 17965, overboost.

**ashatum** · 06-07-2009,12:48 PM

thanks for that. If i got that code then what woul be the next course of action to correct the problem?
thanks for your quick reply
ash

**Crasher** · 06-07-2009,01:15 PM

Usually it means the turbo is clogged with carbon and needs cleaning which can be done chemically although this is not always successful and the best way is to remove, strip and clean the turbo. Occasionally it will be down to a faulty vane actuator but this is quite hard to diagnose with the turbo on the car. If this code is stored, the operation of the system needs to be check using the diagnostic computer in Basic Setting 04, Main Group 011 and the operation of the actuator observed. If it is moving freely the problem is a build up of carbon internally, if it does not move it may be solid with carbon or have a failed actuator. Very occasionally 17965 is down to a failed Air Mass Meter but I have only seen this once.

**ashatum** · 06-07-2009,08:49 PM

thanks very much for your help, i will take the car to have the code read at some point then let u know
cheers
ash

**ashatum** · 13-07-2009,03:40 PM

hi again. any one know how to chemicaly clean out the turbo as crasher said in the previous reply? thourght id try it first if it was just a matter of putting some additive into my tank. any advice appreciated. cheers
ash

**Crasher** · 13-07-2009,04:38 PM

It is a little more complex than that, it is a three stage chemical process that two of the stages have to be pumped into the exhaust side of the turbo once the downpipe has been removed, the third stage is added to a new and empty fuel filter.

**ashatum** · 13-07-2009,07:32 PM

thanks mate you seem to know a lot. do you know anyone in my area you could recommend to take a look? im too scared to take it to vw dealer after hearing too many bad reports. im in the dudley area of the west midlands.
thanks again

**herby0001** · 13-07-2009,08:59 PM

Originally Posted by ashatum

thanks mate you seem to know a lot. do you know anyone in my area you could recommend to take a look? im too scared to take it to vw dealer after hearing too many bad reports. im in the dudley area of the west midlands.
thanks again

Book it in with Crasher and take a day trip to Nottingham. He's the daddy. This chap knows what he is talking about.

**ashatum** · 14-07-2009,10:36 AM

ye may have to do that, its not that far realy and would be worth it to get it sorted. iv been told of people who have unbolted the actuator and wiggled the lever forward and back to loosen the veigns and it seems to work, ive also read that the temp gague can affect the running of the car if its not working correctly, mine isnt! i have a new one but havent fitted it yet but to be honest i carnt see how it could cause the problem. anyway going to have a got at these couple of things then see about getting a pro to have a look. cheers guys