Don't know if anyone can help me but i'm pretty much getting to my wits end!!

 

Have a really annoying issue with my Octy vRS tfsi. When i'm driving it hardish with the throttle wide open, she drives great, no issues.  As soon as I have been driving it moderately with partial throttle, it wont boost properly and can some times go right up to 3500 rpm before WHOOSH in comes the boost...

 

Checked it in a vag com and its showed PO299 boost pressure below control limit, although this only logs intermittently and not all the time.  Checked all the usual stuff, no boost or vacuum leaks, DV is fine as revision D although I did check it, replaced the N75 valve but nothing has cured the issue.

 

Read somewhere on a GTI forum that it could be the intake temp sensor or MAF, tried unplugging the MAF first of all.  Took it for a run and the fault seemed to have disappeared, boosting like normal.  I took the maf and the intake temp sensors out and gave them a good clean with some brake cleaner.  Plumbed it all back together, and eureka all seemed to be well.

 

That was a couple of days ago and guess what, back to normal again.  I'm adamant it's an issue with one of these sensors as unplugging/cleaning seemed to help, but don't want to have to replace them both if I can help it.

 

Anyone had any similar issues? any help would be gratefully accepted!!

I can only offer sympathy. Your problems sound very familiar to many of us TDI vRS owners. I have never found a solution to why my car does a similar thing. It's weird that there are common faults shared between turbo'd petrol and diesel powered cars.

Gonna have to bit the bullet and book it in with someone that knows what they are doing!!

 

I live in Bolton, so close to Preston, Manchester, even Liverpool isn't a million miles away.

 

Anyone recommend a decent garage??

Gonna have to bit the bullet and book it in with someone that knows what they are doing!!

I live in Bolton, so close to Preston, Manchester, even Liverpool isn't a million miles away.

Anyone recommend a decent garage??

Awesome GTI in Manchester could help.

Ian Collins (ICA) in Garstang near Preston is very good, VAG specialist.

Thanks guys,

 

Ended up taking your advice and booking it in with Awesome in Manchester, glad I did too.....

 

Boost issue turned out to be an intermittent DV fault due to the way it had been fitted.  Once replaced they took it on a run to check everything was working and logging as it should, which it wasn't,  The car was mapped prior to my ownership, and as it turns out not very well!!

  

The timing was all over the place and It was running dangerously lean, to the point i'm very lucky I havent cooked it.

 

The guys at awesome lived up to the name and sorted me out with some discount on an APR stage 2 map which is like night and day. Really happy with the results, and although a little pricey much less expensive than a couple of melted pistons.

 

Cant recommend Awesome GTI enough. Top Service.