Ooohhh noooo big problem

[thompa25]

Looks like I have fudged the car while out having a play today. Went over a hump in the road, landed pretty harshly, but I'm not sure of that has any thing to do with the issue, as this appeared about 10 mins after. Basically, the car is really jerky acceleration, like massive power, no power, massive power again, almost like its not getting enough air or something, and the car won't idle, as soon as you take the revs off, or take it out of gear, it dies. It sounds healthy enough when it revs standing still, but I've got a sneaking suspicion it is something to do with the cai I have on it, the idle has always been slowly jerky since I out that on, but nothing major, does anyone have any ideas as to what this might be, I've just sold my other car, and now if broken this one

thanks in advance

 

[Jonathaan]

What car?

 

[thompa25]

Whoops forgot to put that in, it's a 2008 s3 running stage 2 with a hpfp, cai, and miltec exhaust

 

[Ron burgundy]

Boost pipe popped off?

 

[thompa25]

The intake pipe on the cai kit is made from metal, and is absolutely scortching hot, like almost can't touch it, do you think that could be part of the problem, the air is too warm so a lot less dense, messing with the maf? Because it is 24 degrees here, hottest day of the year probably

 

[thompa25]

I had a quick look, couldn't see any loose pipes, I'm going to sound like a moron, but where are the boost pipes, obviously connected to the turbo and the intake, but I'm not even sure where the turbo is haha, front right of the block?

 

[wuta3]

Have a ganders down behind the headlights at the bottom, sort of last thing before the undertray down that gap. or get under and take your undertray off. big massive black pipes with circlips going in to your intercooler.

 

[wuta3]

Im such a great guy, I even amaze myself. I made you a picture:



Where to look from your engine bay, what to look for at the bottom. Somebody might tell me im wrong however.

 

[Sandra]

Im such a great guy, I even amaze myself. I made you a picture:

View attachment 33762

Where to look from your engine bay, what to look for at the bottom. Somebody might tell me im wrong however.

And you are what makes this forum such a helpful and friendly place for taking the time out to help another member. Thank you. x

 

[nluk100]

I would say either the lower boost pipes or maybe you cracked the weld to the turbo flange on your downpipe?

 

[DarkBunny]

Loss of boost pressure wouldn't kill the idle.

Also, it would be permanently down on power - rather that being "on-off".

 

[Ron burgundy]

Loss of boost pressure wouldn't kill the idle.

Also, it would be permanently down on power - rather that being "on-off".

Mine was on and off when the pipe to the egr was half out but your right idle wasn't affected at all when I think back..

 

[thompa25]

Thanks for all the help, and thanks for the picture, it seems to me like the dump valve is constantly dumping the air , or something is letting all the boost out, maybe the diaphragm on the dump valve is gone? But can't imagine that it would affect the idle, as mentioned before. It isn't constantly down on power, just sometimes it won't rev properly, then it will and then it's hesitant trying to rev, if you get what I mean.

 

[S3_Mat]

Do you have access to anything that can scan for fault codes?

ps lol Wuta3.

 

[S3 AEX]

Could it not be the coil packs? Crankshaft sensor/ camshaft sensor?

 

[Yonner]

Sounds like pcv valve to me , mine did somat like this a few weeks ago , I had a slpit in my DV and the seal on the pcv was full of oil , £99 for both parts , me sure you get a new seal for the pcv as well

 

[wuta3]

Sounds like pcv valve to me , mine did somat like this a few weeks ago , I had a slpit in my DV and the seal on the pcv was full of oil , £99 for both parts , me sure you get a new seal for the pcv as well

IIRC the PCV from Audi comes with the gasket. 5 minute job, and does result in erratic idle, but not a massive loss of power. Would be weird to have PCV and DV failure in one go?

 

[Yonner]

IIRC the PCV from Audi comes with the gasket. 5 minute job, and does result in erratic idle, but not a massive loss of power. Would be weird to have PCV and DV failure in one go?

I must off been unlucky because my car runs awesome since both replaced , it was idle lumpy and loss of power , awesome gti sold the gasket separate ,

 

[thompa25]

Well from what im reading from you guys, and else where, it looks like it could be a combination of the forge dump valve failing, and the pcv needing changed, what do you think? Just a stupid question here, the diverter valve is used in conjunction with the oem dump valve, so having a forge DV fitted, i dont have this anymore, is that correct?

 

[Yonner]

Check my posts in this thread mate , you can clearly see the hole in the dv , the oil seal on the pcv also , http://www.audi-sport.net/vb/showthread.php?t=212239

 

[Yonner]

The signs I had to show the pcv had gone was oil near the top of the engine near the coil packs , it sprays there apparently ,

 

[thompa25]

did you have the oem diverter valve, because i have a forge one, not sure if that will have gone, dont want to change just the pcv if the dv is ****ed, because it will happen again, but dont fancy shelling out the money for the forge dv if its not needed.

 

[Yonner]

I had oem mate , check under engine cover for bits of oil ,