Mk5 GTi Hesitation? Low power?!

[DJ_SI]

Hey Guys Love the forum!

I recently bought a 55plate Mk5 GTi from the VW Stealers, absolutely love it to bits, However it has a strange problem with power.
I'm going to explain this as best I can.

Sometimes when you put your foot down, it goes really well, like it should, other times it will go well until about half throttle, then when full throttle, the car doesnt increase speed, sometimes even appears to slow down. . . when the throttle is released slowly, the car almost seems to speed up again. The turbo also seems like it goes quieter under full throttle than half and seems to make no difference to the speed of the car.

I know this sounds a bit vague, maybe like im going mad   But its really bugging me, sometimes it feels alot slower than my old 1.8t  

Things to note:

It doesnt seem to be all that good on petrol anymore. I run it on High Octane, get about 210 miles out of 40 notes. I drive it slowly most of the time so should get over 30mpg?!


The wires and plug of the accelerator are exposed... I thought maybe this means there has been trouble with the accelerator before? could be again??

It is lumpy when idle when the car is warm, sometimes feels like a slight misfire.

it has done just under 38k and has recently had a full service at VW including cambelt.

Hope someone has some Ideas to why this is. I dont want to give it back to VW for a week for them to tell me they cant find a problem.

Thanks again!

Simon

[Top Cat]

Welcome to the forum DJ SI 

A common fault on these cars is the DV splitting which would fit with some of your symptoms. Creating a boost leak.
Also the wires are exposed on the loud pedal on all of our cars so dont worry about that.
If you recently bought it from a dealer then i would take it back and ask them to take a look. Its got to be better than us lot taking a punt.
Where do you live. 

[DJ_SI]

Hi TC

Thanks for the reply. Its going back to the dealers next week as it has the dreaded rear wiper problem (comes on when car starts).

The DV is fairly loud when you let off, gives a half decent pssst sound! Not a chattering sound like the plastic one used to on my mk4 before i got it changed tho.

Is there anything else I can do to diagnose the problem?

Im in Gloucestershire at the moment.

Cheers

Si

[Rich]

I have that lumpy feeling sometimes when the engine is idle...

I've had mine remapped... that might be why...

Be interesting to know if this might mean there is a problem...


Will look forwards to reading other people's answers to these problems...


I'm sure plenty will reply 

[Top Cat]

Hi TC

Thanks for the reply. Its going back to the dealers next week as it has the dreaded rear wiper problem (comes on when car starts).

The DV is fairly loud when you let off, gives a half decent pssst sound! Not a chattering sound like the plastic one used to on my mk4 before i got it changed tho.

Is there anything else I can do to diagnose the problem?

Im in Gloucestershire at the moment.

Cheers

Si

You can take a look at this list of people with Vag- com   http://www.mk5golfgti.co.uk/forum/index.php?topic=120.0

they could check for fault codes which will help with diagnosis.  
Everyone on the list will be willing to help you out if they have time. Have a look and if someone is near you i will send them a PM for you if you want.  

[DJ_SI]

Come to think of it, She does whistle sometimes when you open her up. Could well be DV or boost leak.

Glad I fought for 2 Years Warranty!

I will book it in with VW to get it looked at next week and report back about the lumpy Idle. Means i will have to have the Derv Polo Courtesy car again, which actually pushes you back into the seat!, unlike my GTi lol

Vag-Com would be ace, I have the version which works with all the older OBD-II Cars like the Mk4, But not the new CAN-BUS Version for the Newer Cars etc.

[joesgti]

ive had loads of problems with my dv and had symptoms like you have said.

the first thing id do is get the car up on a ramp or axel stands and check the DV out, take it off and re fit it, also make sure its mounted propably as awesome fitted mine sideways!

[SteveS]

i get quite a whine when i put my foot down and the turbo spools. i thought that was normal?

[ub7rm]

From my mk4 days the MAF is another likely culprit for this type of behaviour and until it completely fails doesn't throw up any fault codes.

[Phil Mcavity]

i get quite a whine when i put my foot down and the turbo spools. i thought that was normal?

K04's are louder then the K03's steve  

[TomB]

It sounds very much like my GTI at the minute.

The dealer looked at it the other week and said the turbo wastegate has gone, but I think he meant actuator as he said the replacement was only £18.

[greent2]

Hi
 
I have the same hesitation, some times lumpy at tick over then under acceleration the power becomes a bit washy. Has anyone had there motor fixed yet ?

[Corum]

Hi all. My first post here!

I have had a 55 plate GTI DSG since new. Been an excellent drive until recently when I started to get an occasional lack of smooth power under load. Very noticeable on hills or the open road when you have a chance to accelerate.
You can see the rev counter falter and it feels like a fuel problem. No different noise that I can hear.
Main dealer could find nothing on diagnostics. Changed coils/plugs.
Local indy VW specialist (a few days later) said car reporting fault in air intake manifold motor and in turbo. Replaced motor - total £280. Management light is off/on, and the economy seems down a bit.
Changing the intake manifold motor has made no difference.
Before I replace turbo (ouch) and ideas?
Talk of MAF sensor but neither garage has found a fault?
Help please.....

[Aas]

I have exactly the same symptoms as the original poster and I have ordered a new diverter valve from vw should pick it up tomorrow. I done quite a bit of research on the forums and it seems quite common, so worth a try for £54 prob cost that to have it plugged in at a dealer.

[martziniuk]

Lumpy idle, general poor running..... I would check the PCV.