Poor running

[prowlerflyer]

So I just finished changing the OFHG (btw, far bigger PITA with the TS2) and start up the car and its running horrible. Symptoms; large stumble at idle and a high pitched whistle. Test drove the car and it pulls smoothly like a champ, but below ~1500rpm it starts getting lumpy. By the end of the drive, the idle had improved a bit (it at least idles now, although I am not sure if its all 6 cylinders), but the whistle hasn't changed.

I did degrease that side of the motor before starting the gasket replacement. So my thought on the rough running was water intrusion into a sensor or plug. Ran the scanner, and the car is not throwing any code other than the DME code 281E [10270] Variable air intake system: activation. Don't know what that is, but I assume its DISA, but with the TS2 I don't have a DISA valve.

The whistle I am at a loss for. I am pretty sure its not belt slippage (wrong sound, and all belts & tensioners are just a couple of months old). Double checked intake connections and everything looks connected properly. The whistle seems very throttle responsive and disappears as rpms rise. As I said also the car is pulling strong, so I am guessing I do not have a boost leak.

Looking for some wisdom and suggestions. Thanks.

Steve

[danewilson77]

What did you remove to perform the gasket replacement? I assume car was running like a champ beforehand.

"No flamesuit required"

[prowlerflyer]

Your tight Dane, was running perfect before, minus the oil leak. I removed intake/airbox, main belt tensioner, and alternator, and just moved the PS reservoir and pump.

With the TS2, the OFH has to be snaked out downward to get under the S/C drive shaft and then up and out through the airbox hole. The only electrical things I remember unplugging are two on the OFH by the VANOS line.

[danewilson77]

I would say your best bet is to give it a once over. You may not have gotten something seated right intake wise.

"No flamesuit required"

[JupiterBMW]

Yeah, I've got to agree with Dane here... I was immediately thinking some sort of vacuum line, but you said you checked everything. Who knows, give it a day and then go back and look at it. Sometimes a fresh start will help you find stuff you missed previously. Good luck, hope you get it running well soon, I know how that thing pulled when I drove it, would be so tough to not have that!

[prowlerflyer]

I have already met my frustration point for today Joop, and will re-attack tomorrow. Mulling my strategy over a beer, Elysian Bifrost, quite tasty.

I have to take the car in for the airbag recall Monday, and it would be embarrassing to bring it in running the way it does.

[danewilson77]

I'm taking mine in Monday as well. Absolutely cannot wait for "the list".

"No flamesuit required"

[JupiterBMW]

Glad to hear you guys are handling those recalls. Hate the thought of my brothers driving around with unsafe airbags...

[prowlerflyer]

Now I did find the hard line off this disconnected. I am not sure what it is, but if that is a vacuum line, it could affect the idle.

Any ideas on what it is and where it goes? The line's orientation would have it going backwards under the intake manifold.

[prowlerflyer]

Well, mystery finally solved.

The above part had a flexible line, a hard line and a electrical plug coming out of it. The hard line ended up getting pulled out of a larger flexible line coming out of the bottom of the S/C. I am guessing it was part of the idle circuit (oddly the part # on it does not come up in real OEM). Re-inserting the line cured the bad idle and the whistle. Real pain in the a** to get at the bottom of the S/C, ended up having to remove the aluminum under engine brace to be able to get my hands up in there.

Towards the end of this drama, my wife comes out to the garage. This is the following conversation as I am cleaning off the under engine brace:

Wife - Did you fix it?

Me - Yep. Almost done.

Wife - Was that part really dirty?

Me - No, just making it look nice.

Wife - Can you see it when its on the car?

Me - No, its under the car.

Wife - Isn't it just going to get dirty again?

Me - Yep.

Wife - Ok, do you need a beer?

Me - No thanks. I think I am going straight to whiskey when I am done. Thanks Babe.

[ELCID86]

LOL. Sounds like a great lady! Glad you got it solved.

[danewilson77]

Awesome!

"No flamesuit required"