A few TDI Problems - What to try next

[mrapoc]

Hey.

I serviced it about 5 months ago. Havent had decent mpg since owning it tbh. I have a feeling that the map on the intercooler/boost leak may be what im looking for...

[mrapoc]

Right an update

Changed the MAP sensor on the intercooler (thrust) and PSI adjusted my actuator as it was overboosting (still is tho..)

Also had it mapped to see if it was a bad map. Hard to say if its any better.

Only thing I can think of now is if the manifold is blocked up (would a clogged manifold really fook up mpg?)

Also maybe something more serious like loss of compression, i dunno.

The way i describe it is, once i get to a speed like 70, i should be able to hold that speed, but it starts falling in speed once i get a decent mpg. To hold it I have to accelerate back up, hence losing the mpg

[scarr89]

Wow, very strange symptoms...Really hope you get it sorted mate. Scanned it for any codes? Perhaps do some date logging while running the car, see what reading your getting on all variables? 

[kennedyuk2001]

If your car is struggling to maintain 70 without giving a little extra then maybe you have a sticky caliper?

[mrapoc]

Wheel seemed to spin quite freely. But yeh it is almost like it needs that extra acceleration as it won't just hold it there.

No faults over than when i get it to overboost (full throttle)

MAF is ok. Boost is ok (apart from full throttle). Best way to check for sticky caliper?

[kennedyuk2001]

Check all four wheels, get it in air, push brake then spin a wheel, should roll fairly easy and not have much resistance and roll to a steady stop not too suddenly. Check all wheels, as could also be sticking handshake issue.

[tdi_blu]

Hi Im not that clued up on engines etc but I thought I would mention my fault that I had as at least you could check it.My own car not to long ago had issues where it was crap on mpg and losing power and eventually as things got worse the car would cut out completly.I changed all sorts of things and we could not find the problem and at one point I just felt like setting fire to it  Anyway by sheer chance when it was in the garage a vw tech was also there picking up a car and asked what the problem was we explained and he went straight to the back seat had a look under at the fuel pump and explained that the in and out on the pump was the wrong way round and the car was being fed fuel only through the drip rail is it something like that.Apparantly its a very common fault on mk4 golfs and it happens why its being built in the factory whats mad really is that the cars can run perfect for years but then at random start to play up.Could well have nothing to do with your fault but I just thought its worth a mention,stick with it you will get to it in the end 

[mrapoc]

Fuel pump is correct but cheers mate

I have tried wheels but ill try again after pressing brake pedal

[mrapoc]

Blocked cat or timing maybe 

[sprout99]

is your EGR stuck open?