Hi folks, is it possible that a failing exhaust can cause intermittent problems with turbo not working fully/jerking/going into limp mode? I have just contacted the previous owner of the car who said he did not have any problems with the turbo but p/ex'd his car because it needed a new full exhaust/catalyst, so opted for a change in car (!?!?). It does not sound like it is blowing, although I have not seen underneath yet. Cheers folks.

Hi folks, is it possible that a failing exhaust can cause intermittent problems with turbo not working fully/jerking/going into limp mode? I have just contacted the previous owner of the car who said he did not have any problems with the turbo but p/ex'd his car because it needed a new full exhaust/catalyst, so opted for a change in car (!?!?). It does not sound like it is blowing, although I have not seen underneath yet. Cheers folks.

nothing to do with exhaust it sounds like n75 valve it is directly behind dump valve

nothing to do with exhaust it sounds like n75 valve it is directly behind dump valve

Also could be a dirty throttle body ,coil packs,can you explain a bit more whay exactly it is doing?

If it's gone into limp mode it'll have thrown a fault code. Get Vagcom diagnostic on it, & that should point you in the right direction.

Thanks for the info folks. My Octy 1.9tdi runs lovely when not using the turbo and runs great from cold, however, when engine starts to reach normal temp, my turbo struggles to kick in and, if i floor the pedal, it will go into limp mode, fixed only by recycling the ignition. I have changed the MAF but no fix. My N75 valve makes a lot of clicking noise (continually) if i recycle the ignition without starting the engine. I have also had a look at the EGR valve (some oil, not a lot, and no carbon build up and cleaning spray administered) but only when attached to the car as I could not get it off. Once it has gone into limp mode and been recycled, the car is great and turbo really does the job, however, if stuck in traffic for a while, the problem returns again. My hand held diagnostic tool found no codes once limp mode occurred. No smoke from exhaust, MPG around 38 in town, but i do get a funny squark/suction noise when car is about to kangeroo into limp mode. This fault is really playing with my head and I have been informed that a code may not appear with this type of fault so am dubious about sending it to garage. Any further ideas?

I have similar problem with 2002 2.5 TDI Superb Mk1,on about 150.000 miles had engine blow,fixed all,new heads,valves,pistons,new turbo because fragment of a exoust valve destroyed it.Went poor after that,went to other garage,guy played vith variable geometry of turbo-went superb for a day,than again sluggish with lot of noise,service changed hy presure hoose at intercooler because it cracked-went grate for a day,service say its vp44-fixed it-same thing only beter consumption. The newest finding i that it is probably the CAT,because it is hissing and cover for turbo-heat sheeld is black from soot. Sorry for bad english. Any apinion?

Thanks for the info folks. My Octy 1.9tdi runs lovely when not using the turbo and runs great from cold, however, when engine starts to reach normal temp, my turbo struggles to kick in and, if i floor the pedal, it will go into limp mode, fixed only by recycling the ignition. I have changed the MAF but no fix. My N75 valve makes a lot of clicking noise (continually) if i recycle the ignition without starting the engine. I have also had a look at the EGR valve (some oil, not a lot, and no carbon build up and cleaning spray administered) but only when attached to the car as I could not get it off. Once it has gone into limp mode and been recycled, the car is great and turbo really does the job, however, if stuck in traffic for a while, the problem returns again. My hand held diagnostic tool found no codes once limp mode occurred. No smoke from exhaust, MPG around 38 in town, but i do get a funny squark/suction noise when car is about to kangeroo into limp mode. This fault is really playing with my head and I have been informed that a code may not appear with this type of fault so am dubious about sending it to garage. Any further ideas?

You need to get it diagnosed with VAGCOM. If it goes into limp it will have thrown a code, but your code reader obviously doesn't recognize it. If you think it's temperature related that possibly points to a CTS fault.

Edited 21 August, 201114 yr by pauldazzle

As with Paul. Didn't you have a thread on a similar nature back in mid Feb?

Arh yes, a quick search has found me this:

http://briskoda.net/forums/topic/191127-turbo-problem-or-sensor-fault/

Did you ever get to the bottom of it back then?

Could be a boost pipe popped off or split

Sticky vane problem My link, click on vwtdi then VNT Turbo Rebuilds - Cheap! Gives a good discripsion of your problems