S3 Problems

[psycosonic]

Hello,

My S3 ('03) is giving me some serious headaches..

It fails a lot when i smash the accelerator, and giving me misfire problems in all cylinders. Already changed the sparks, DV, cleaned the TB, new fuel filter..

I think the MAF is not ok either.. could the 4 coilpacks be mad?

Bad coilpacks... bad MAF... ? The turbo only does about 0,3 bar boost..
N75?

Here are the vag-com results:

5 Faults Found:
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16688 - Cylinder 4 Misfire Detected
P0304 - 35-00 - -
16686 - Cylinder 2 Misfire Detected
P0302 - 35-00 - -


Thanks,

Best regards,
John M.

 

[Dani_B19]

Change all four coilpacks for geniune items and then take it from there also log you MAF readings and then that will give you an idea if thats out or not.

 

[psycosonic]

Change all four coilpacks for geniune items and then take it from there also log you MAF readings and then that will give you an idea if thats out or not.

Could the coilpacks influence the boost pressure? I'll start by changing the four coilpacks... thanks !

 

[Dani_B19]

Have you checked all the main boost hoses and clips?

 

[psycosonic]

Have you checked all the main boost hoses and clips?

Yep, they all seems to be OK. Are there differences between 1.9TDI PD 150hp MAF and 1.8T MAF ? At least the housing is the same.

 

[psycosonic]

Hello again,

New MAF, new coilpacks and new sparks. Cold start problem solved.
The problem now is when the car starts to boost, when i smash the accelerator pedal, it fails. Like... hesitating.. if i don't smash the pedal, it runs fine.

Starting to be sad...

 

[voorhees]

remapped ?

 

[psycosonic]

Stock file... already checked that.

 

[voorhees]

temp sensor ?

 

[golf]

I have the same kind of problem with mine, still unsolved.

The turbo, N75, diverter valve, N249 valve and the MAF have all been changed by the previous owner. The problem is still there and the it's intermittent; sometimes the car will boost as normal and there'll be no problem but other times it's like driving a 1.8 NA at high revs until you change gear and the boost comes on. It's driving me mad!

 

[voorhees]

I had the same problem thats why I have replied,overnite I still have a half second hiccup.
must be another trait !?

 

[psycosonic]

Now i've made a reset with vag-com (Engine module, adaptation, 00, save)... misfires started again... god!!!!

 

[psycosonic]

What should be the requested boost? S3 1.8T 225hp... 1.1bar?

 

[psycosonic]

Cold start problems are here again! Crank sensor? N75 could cause cold start problems?

 

[Pinola]

Stock file... already checked that.

how do you check if your car has been mapped or not?

 

[[Dave B]]

Maybe it's time to stop 'smashing the accelerator'....? But more seriously I have no idea what it could be.

Uselful, I know.

 

[psycosonic]

how do you check if your car has been mapped or not?

I don't know if it has been remaped or not.. but i know that the ecu has the original file.

News.... this happends after i do this at VAG-COM:

Engine - Adaptation - Channel 00 - Read - Save... this should do a reset.

 

[psycosonic]

The car doesn't misfire now.. but it only does 0,35bar boost.. when the ecu is requesting 0,85bar. N75?


EDIT:

Just found out this:

But i don't know if the leak is that big..

 

[Broken Byzan]

SMIC top hose is leaking by the looks. Have you cleared the codes, as you could be in limp mode.

 

[psycosonic]

SMIC top hose is leaking by the looks. Have you cleared the codes, as you could be in limp mode.

Engine codes? It has no errors at the moment... so i made no clear..

 

[Dani_B19]

That the drivers or passengers SMIC?

 

[psycosonic]

That the drivers or passengers SMIC?

Drivers. Leak fixed, problem still there.

 

[fran-s3]

I had similar problems to this, my car would always missfire on full accelerator... Replaced MAF, sparks, coil packs etc... and checked VAG and looked for leaks.

Turned out to be my fuel pump failing! It was fine when non-mapped, but it bough it out. Check to see if your car is running really hot after a run, I mean roasting under the bonnest as that's a classic symptom. VAG-COM won't show it, least it never did on mine! Worth checking, it drove me insanse! It'll be something mate, take it to a professional garage like I did. APS eventually found the problem after they to replaced every sensor under the sun.

 

[millwrx]

as per last thread my one does the same will be checking the fuel pump,i have a new fuel pump but not sure if its the right one

 

[cabby86]

My car had the same problem when I purchased it, it turned out the car was mapped, which I wasn't aware of when I purchased it, had the standard map put back and I have not had any issues since. The specialist I took it to thought it might have been the coilpacks struggling with the extra power, but that was just a guess.

Chris