2.8 V6 Engine

[PlebbyChris]

Just a quick thread, can someone tell me what the idle speed for a healthy 2.8 V6 should be?

Mine keeps trying to drop down to about 400rpm and just wondering if it's that which is causing stalling and whether it needs resetting. If that's about right then I need a new throttle valve.

Cheers

 

[Rev-head]

ISV will need cleaning or replaced ISV =Idle stablization valve which controls the the idle speed

If you go on to www.audiworld.com click on resources-tech info-engine should info regarding cleaning ISV

cheers

 

[Rev-head]

just checked and guy has done write up under ICV a little confused he is but good pics and detail

 

[PlebbyChris]

Had a quick look at the article for cleaning the ICV, haven't had a chance to compare it to mine. Do you reckon it's exactly same layout for a 30v? As the article refers to a 12v.

I've looked on ElsaWin workshop manual and they say to clean/replace the throttle valve. I assume they're referring to the same item.

But out of curiosity, what should the stabilised engine idle speed be? Anyone?

 

[Rev-head]

800rpm i would say......should not be far off the same i would have thought.........yes same thing

 

[Drmatrix]

900rpm

 

[Drmatrix]

goes higher when you first start the car then settles down when the engine has warmed up

 

[PlebbyChris]

Yeah, mine jumps to about 1200rpm on first starting and gradually drops down. If it stayed at 800-900rpm then I think it'd be ok but it tries to drop it down to about 300rpm at times and so nearly stalls.

Cheers for your help peoples, much appreciated.

 

[timsp8]

Different engine but when I got my 2.7T (tip) it had intermittent slightly irregular idle (revs dropping to 400) and lurched occasionally when creeping in 1st or reverse manouvering out of my drive and in car-parks. Took it back to the independent who supplied it and they cleaned the throttle body. That made no difference. Found a suggestion online that the aircon was the "cause". I've found that if I switch the aircon off when manouvering I no longer have the "problem".

May have nothing to do with your 2.8 but worth a try if you haven't already.

Tim

 

[PlebbyChris]

Yeah I've heard a few likely causes, think i'm going to have to just experiment. I've given it a service, that seems to have helped a little. I've tried turning the air con off and it does help a little but problem is still noticeable. Think the throttle valve is most likely problem so at first possible chance I'm going to replace that rather than clean it. I've also heard that the coolant temperature sensor can create slight lurching problems if it has intermittent problems but not had any fault codes or anything to indicate that.

 

[Drmatrix]

Let us know what the results are dude

 

[PlebbyChris]

I've just tried a little test to help out. I've managed to get the engine to idle back at 850-900rpm without doing too much. The response when dropping back down to idle is still slightly iffy but it helps as a temporary repair.

All I did was remove the air intake hose just after the MAF section (while engine was off, otherwise it cuts out) and then sprayed a mist of WD40 down the hose towards the idle control valve. Then connected it back up and started the engine as quickly as possible afterwards to suck the WD40 through the engine. It has definitely helped, which would indicate that it is the idle control valve at fault, probably just gummed up.

It's a fair improvement on how it was but will still definitely need removing at some point for a proper clean out.

 

[PlebbyChris]

Have managed to stabilise the engine by replacing the throttle valve, couldn't believe how much oil there was in the old unit.

Is there anyone out there with same idling problems that is looking to replace their throttle valve? I've managed to clean out the old unit, it is fully de-greased and cleaned up, the control side is pristine and should work a treat.

£50? Any takers?

 

[jimp]

No thanks, man...

Is it fixed? - got a 2.8 myself

 

[PlebbyChris]

Yep, all fixed.

The problem was a layer of gunk around the disc in the valve, so when it actually dropped down to idle then the disc completely shut off the intake.

There is still a small shuddering that i believe is down the a dodgy oil breather hose, but still awaiting parts to replace that.