S3 210 overboosting!??

[DJ_Troopa]

Evening everyone

I've noticed recently i have a problem with my S3 210. When i give it a boot the revs seem to stop at let's say 4k for a couple of seconds and then carries on but without much boost?

Went to my VW teccy this evening and had it on the VAG-COM and it came up with, Charge Pressure: Maximum limit exceeded. After a drive logging at different speeds, the conclusion is my car running at 32psi! We had a look at the N75 valve and it's an 'F' version. Shouldn't i have a 'J' version? Does anyone know how i could resolve this and what the problem might be?

Appreciate it people.

Jay

 

[1animal1]

nope the J version is a mod, not sure what it should be though.....

 

[S3 Paul]

Ive got one from a 210 amk engine car in my locker at work... i will post part number and code in the morning if you wish? It was the standard one so will be the correct code for a 2001 amk 210bhp s3 if that helps.

 

[DJ_Troopa]

Ive got one from a 210 amk engine car in my locker at work... i will post part number and code in the morning if you wish? It was the standard one so will be the correct code for a 2001 amk 210bhp s3 if that helps.

Yes please Paul, that'd be brilliant. Really confused as to what's wrong with the car and why it's acting like this! My teccy thought maybe the wrong N75 is in there?

Cheers

 

[1animal1]

if he knew the engine he should know its not supposed to be a J valve..... that valve either works or gives you limp mode as its for a much older car

 

[DJ_Troopa]

if he knew the engine he should know its not supposed to be a J valve..... that valve either works or gives you limp mode as its for a much older car

Hmmmm i've got an F version in there? So is that the right one? Only got the car on monday and can't believe this has popped up already! lol grrrr!

 

[DJ_Troopa]

Been having a search for the past god knows how long and seen people stating it's the n75 valve or a boost leak?

Jay

 

[golf]

Overboosting is generally a sign that the N249 valve is not working properly. Ideally you'd need to get the car scanned on Vag-Com otherwise you'd be forever guessing.

 

[DJ_Troopa]

Overboosting is generally a sign that the N249 valve is not working properly. Ideally you'd need to get the car scanned on Vag-Com otherwise you'd be forever guessing.

We checked the car on VAG-COM last night and it stated, Charge Pressure: Maximum Limit Exceeded.

 

[DJ_Troopa]

Found this:

http://wiki.ross-tech.com/index.php/17963/P1555/005461


17963/P1555 - Boost Pressure Control: Upper Limit Exceeded

Possible Symptoms

• Reduced power output
• Limp mode

Possible Causes

• Boost Pressure too High
• Hoses/Pipes incorrect connected, disconnected, blocked or leaking
• Charger Pressure Control defective
  • VNT (variable nozzle turbo): nozzles stuck
• Solenoid Valve for Boost Pressure Control (N75) defective

Possible Solutions

• Check Hoses/Pipes to/between Components
• Check Solenoid Valve for Boost Pressure Control (N75)
• Check / Clean / Replace Charge Pressure Control
  • Check / Clean mechanism for variable nozzles

 

[MintyS3]

As has been said in previous threads abnormal boost levels, spiking etc can be caused by a dodgy n75. I would stick with the original i.e avoiding the J version.

 

[S3 CYP]

DJ Troopa,

This occured on mine not so long ago - It was a faulty N75 making the car boost to 1.5bar and then hit limp mode - mine was an F version. The N249 was fine in my case.

Chris

 

[DJ_Troopa]

DJ Troopa,

This occured on mine not so long ago - It was a faulty N75 making the car boost to 1.5bar and then hit limp mode - mine was an F version. The N249 was fine in my case.

Chris

Hey Chris, thanks for that.

So when you got a new N75, what did you ask for exactly? Just another N75 F version? So you're saying my N75 could be faulty and just needs replacing?

Thanks!

 

[S3 CYP]

DJ Troopa,

I took my car to Wak of Vagcheck after I got the same fault code. We did some data logging and found out the problem to be the N75 as the DV, MAF and Coils were all 1 week old.

Replaced the N75 (part No 058906283F) another data log while on the road and problem solved.

Now if your car is currently in limp mode I dont think the replacement of the N75 will resolve the problem without removing the fault via VAGCOM, I'm sure someone will confim soon.

Chris

 

[badger5]

Yes please Paul, that'd be brilliant. Really confused as to what's wrong with the car and why it's acting like this! My teccy thought maybe the wrong N75 is in there?

Cheers

dont J valves plumb differently, in which case that may explain your uncontrolled boost and max pressure exceeded

 

[Welly]

dont J valves plumb differently, in which case that may explain your uncontrolled boost and max pressure exceeded

It is easy to incorrectly fit a J valve. But if fitted upside down (Which is the only way you can fit them wrong really) it will limit boost to 5 PSI as boost will flow straight to actuator, rather than back into TIP.

Damaged/kinked actuator pipe maybe?

 

[1animal1]

best replacing what you have....bringing the J valve into the equation could skew the problem your trying to solve

 

[Welly]

best replacing what you have....bringing the J valve into the equation could skew the problem your trying to solve

Agreed, get a replacement identical valve. J valves can induce soft limp on their own, you might end up solving one problem and creating another!

 

[DJ_Troopa]

Thanks for the replies guys. So just replace it with another N75 F valve and go from there i guess?

Much appreciated.

 

[Welly]

Yep, do that and see what you've got. Fairly inexpensive at around £50 from Audi. At least you know the most likely culprit is good if the problem continues.