Arg - Rough idle..

**Bigglezworth** · April 23rd, 2015, 02:20

Happened on the way home and came out of no where. No CEL and no immediate codes on autoscan. Great at wide open throttle. Sounds like my old Chevelle running a solid lifter cam with .560 of lift w/ 260deg duration at .050. lol Lopey

Place your bets...
SJP
MAF
Vacuum hose

I will scan select measuring blocks on the weekend. Time to pull out reserve #2 in the mean time.....

**s8prtotype** · April 23rd, 2015, 03:00

on my car it was the cam chain tensioners haha, partly maf seals... so hard to tell with these cars... break out the smoke machine!

**4everRS** · April 23rd, 2015, 04:43

I'm going with mafs. One of them shit the bed.

Did you scan it?

**RSoverAll** · April 23rd, 2015, 04:50

I wanna play, my guess is Maf(s)

**ScottW** · April 23rd, 2015, 12:13

I'm going with MAF. I just had the same problem.

Replaced one MAF, pcv valve and hose, compression and smoke test, intercooler pipe and a few other bits.

Car is finally running as it should. Finally.

**ben916** · April 23rd, 2015, 16:25

I will play, eh!

It's the hoser, ya hoser!

**Other_Erik** · April 23rd, 2015, 16:39

I'll play! My money is on electrical gremlin, no actual part(s) problems.

**Bigglezworth** · April 26th, 2015, 00:15

And the winner is......

Not the MAF's. They were reading just fine between 3.5 & 5.0. Rough idle was sporatic and after I took it for a quick drive around the block noticed the illfated stiff brake pedal. Confirm with a simple spray of Simple Kleen MAF sensor cleaner down near the PCV valve that the engine RPM's rose noticeably which confirms vacuum leak.... Damn. lol

I would have preferred it being a simple MAF issue.

**RSoverAll** · April 26th, 2015, 00:35

Ahh, well can't guess them all correctly.

I thought a vacuum leak initially but figured it would cause a lean code as well.

**kruat** · April 26th, 2015, 06:52

Least it was a somewhat easy find.

**4everRS** · April 27th, 2015, 03:11

Icky.

Can you hear it?

Sounds like you might have to pull the intake....

**ttboost** · April 29th, 2015, 01:43

It's probably the air leaking past the MAF's. Stupid O rings...I just wrapped black tape around my MAF's, shoved them back in...lasted for years...but I had my MAF's disconnected from my MAF's too.

**rs6BC** · April 30th, 2015, 21:46

There is a 3 way intake valve that will affect your brake pressure and idle. Just had mine replaced. $20 part, 9 hours labor

**A4V8swap** · May 10th, 2015, 00:59

hey rs6BC. My car I believe is having this issue. It was idling weird and then a few miles later no brake pressure at all. I can hear a large leak under the intake it seems like. I pulled the carbon box with MAFs, tried to look around but nothing.

I fear I may have to pull the intake as well. Just wondering if your issue sounded like this. Also need to look into a DIY for removing the intake manifold. Anyone have any insight on this? How horrible is it?

**4everRS** · May 10th, 2015, 02:55

Originally Posted by A4V8swap

hey rs6BC. My car I believe is having this issue. It was idling weird and then a few miles later no brake pressure at all. I can hear a large leak under the intake it seems like. I pulled the carbon box with MAFs, tried to look around but nothing.

I fear I may have to pull the intake as well. Just wondering if your issue sounded like this. Also need to look into a DIY for removing the intake manifold. Anyone have any insight on this? How horrible is it?

Yes, you will unfortunately need to pull the intake. It seems like quite a job. Brav did a diy a while back. There is a plastic valve under there that can apparently crack.

**A4V8swap** · May 14th, 2015, 05:31

RS6 help please! Need help. Have a broken piece under my intake manifold (huge vacuum leak and no more brake booster hard as hell). I've isolated it to this with brake cleaner to test for a leak and a common problem apparently.

Anyone she's basically off. And I'm normally a pretty self sufficient guy don't ask for much help but I think I may need it. Basically removed. Bi pipe. Fuel rail, anything associated top of it. Wiring harness blah blah. At the back of the manifold there's the charge pipes back there with quite a few lines and hoses that I don't want to remove. I have tried to gently pry this off with the bolts removed but there is a dowel almost where the piece sits on the intake and I can't get it to slide off. Other then that I should be golden to get it off.

Anyone ever remove an rs6 intake manifold? Thanks.

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**A4V8swap** · May 14th, 2015, 05:41

Well looks like I just need to stop being a weiner because from the photos Brav had the same issue and just pried it. I just really don't want to break anything.

http://www.rs6.com/showthread.php/23...ugh-idle/page4

**A4V8swap** · May 14th, 2015, 07:15

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