[Captbudman33]

2008 Redline 2.0 Turbo. 59000 miles
Problem:
Idle warm - varies between 780 and 810 not smooth
Idle 850 and above idle is Smooth and Stable
AC on Idle. Drops to 765 at AC start
Then goes up to 793 to 810 but rough
Cold start idle speeds do bounce 50 rpm or so dropping thru the warm up process.

Numbers. MAF 5 to 6 Lb min at idle
Map. 43. KPa at idle
Fixes tried :
1). Belts changed Steering was tight
2). Air filter changed
3) Plugs changed AC Delco Iridium .32 gap
4) MAF cleaned
5). MAPs cleaned
6. Techron added to 92 octane Fuel thinking injectors
7). Had a P0011 Code come up so change out the Cam sensors both intake and exhaust. Codes cleared.

Has anyone had this type of problem ? Lookin for Help and some advice on where to look next. I’m old school for a problem like this give me some carb cleaner and mixture and idle screws this would have been fixed in 5 minutes.
Thanks

 

[BlueRL]

Yeah, I am old school also. Back in the carb days I knew juust what to twist. BUT, I do remember that I spent many a weekend "twisting". Now with the Fuel Injection, I dont open the hood often enough to even know where to look for the carburetor.......

 

[Captbudman33]

Yeah, I am old school also. Back in the carb days I knew juust what to twist. BUT, I do remember that I spent many a weekend "twisting". Now with the Fuel Injection, I dont open the hood often enough to even know where to look for the carburetor.......

You Bet !
I just sold my last Classic Opel GT and decided it was time to get into my Wife’s Redline.
Geeze was that a mistake ! Normally I would just take it to the Dealer but my last encounter with a Chevy Shop and $1800 later figured out they didn’t have a Clue how to handle this car So back to the mechanic I trust ME ! Tried to talk to the ECM but it just laughed at me. This was the first car my wife ever bought so I’ve got to get it right. Besides it’s a Opel GT in Europe.
Thanks for your interest 👍

 

[bioburner1]

Could be a coil going bad. Try google and will find that a rough idle is #1 or 2 symptom of bad coil. My little ford 2.0 with Mazda engine had same issue. A laser temp gun can help spot which hole is having bad fire

 

[TomatoSoup]

Coupla things... the throttle body butterfly can get gummed up and sticky: Pull off the rubber intake tube beneath the throttle body and squirt TB cleaner up and into the body around the butterfly.

Two, may be a misbehaving coil pack, but you (apparently) have no misfire codes, so I tend to doubt that.

 

[bioburner1]

Dirty MAF can lead to rich low idle. My Jeep had this issue. MAF cleaner is not that expensive to rule that out

 

[sahein]

I wonder what the difference is between MAF clean and Brake clean. I have used brake cleaner before without detriment. Brake cleaner is usually a lot cheaper.

 

[bioburner1]

Google it.
Im not going to be the test subject over 5 bucks. CRC is top shelf products for electrical

 

[Captbudman33]

Ok Guys time for me to get back to work. First please understand that I am working without a shop manual
so I might ask stupid question! So what I’ve found on my quest to find the throttle body on our turbo 2.0.
i traced the filtered air duck down to what I would suspect is the throttle body and removed the duct because the clamps were loose. Inside the inlet to the turbo there was a bit of oil on the bottom of the inlet. But inside there was a free wheeling impeller but couldn’t feel a throttle butterfly plate. So I stopped there to make darn sure I was dealing with the throttle body and not the turbine blade. I’ve attached a couple pix of the duct and inlet. Gets more interesting and TomatoSoup thanks for your 2012 post on the check valve attached to the duct. Guess what ! My inlet nipple has in fact cracked off so another job to do when the 3/8 fuel line tool comes in. So here’s where I’m at ! If in fact this is the throttle body it needs to be cleaned out but I’ve read posts that say to pull it off before cleaning so as not to damage the turbo or the engine. True ? Or is it better to run a cleaner injection thru it while running. Pix are attached. Thanks for all your ideas and help 👍
Bud

 

[TomatoSoup]

You are on the completely wrong side of the engine You've been looking at the turbo.

Move over to the DRIVER side and follow the (aluminum) intake pipe from the intercooler, back to where it transitions to the rubber hose. That rubber hose bends up vertically at the rear where it joins the throttle body at roughly the midpoint of the engine. That that rear end of the hose off and squirt your cleaner up into the TB. Leave the engine off while you do it, and wait until the cleaner has fully evaporated before you reattach the host and start the engine.

UPDATE: I searched for a picture... at the middle/bottom of this pic, you can just see the forward end of the rubber intake tube that mates with the TB - just to the left of the brake reservoir. I, ahem, should've maybe mentioned that the TB is quite buried underneath the intake manifold.

 

[Captbudman33]

Awe man I was afraid your were gonna say that but couldn’t believe they would send unfiltered air direct into the intake. Your right this one’s not gonna be fun. Thanks

 

[TomatoSoup]

... couldn’t believe they would send unfiltered air direct into the intake. Your right this one’s not gonna be fun. Thanks

I'm not sure what you mean... The air is filtered through the big air filter box at the from/middle of the engine, then into the turbo to be pressurized, then across through the intercooler to be cooled (and made more dense) and then into the TB.

Don't get too worried about the picture, although it can be a pain to get to the worm bracket to take the hose off, once removed it should be easy enough to get access into the TB with the cleaner. Of course, you may have to make a small blood sacrifice to the God of Mechanics.

 

[Nasher]

 

[TomatoSoup]

^^ Oh, well spotted!

 

[Captbudman33]

Holy Crap !!!
Never even saw that you have to be working with young eyes ! Hose will be replaced tomorrow!
Finally took some time and went thru the intake box and ducting to the turbo and TB. Starting to make a lot more sense now. Thanks
Hope to get into the TB tomorrow also but thinking to loosen the mounts on the aluminum inlet pipe to get a bit more wiggle room. Do-Able or not ?
Bandaids are on the bench for the Blood Letting !!!
Let Ya know how it goes.
Thanks to both of you 👍

 

[CoopSky]

Once again proving why I love this site so much!

 

[Captbudman33]

Idle update !
Throttle Body cleaned. Loss of Blood minimal !
Cracked vacuumed hose fixed
Turbo duct valve nipple rebuilt
Outcome !
Idle has Stabilized but still not smooth especially when AC is on.
If I could get the ECM to give me 25-50 more Rpm it would be perfectly smooth.
Is there anyway to do this ?
Or just live with it
Thanks Again for all the help !
Bud

 

[sahein]

Idle update !
Throttle Body cleaned. Loss of Blood minimal !
Cracked vacuumed hose fixed
Turbo duct valve nipple rebuilt
Outcome !
Idle has Stabilized but still not smooth especially when AC is on.
If I could get the ECM to give me 25-50 more Rpm it would be perfectly smooth.
Is there anyway to do this ?
Or just live with it
Thanks Again for all the help !
Bud

 

[Captbudman33]

Ok so my Kobra OBD2 and Dash Command say my idle at 167 degree coolant temp is 750 and stable but
still rough and with AC on drops to 725 then picks back up to 750 but rougher than it should be.
So what am I missing ? How do I get the idle back to 800 and smooth?

 

[bioburner1]

R

Ok so my Kobra OBD2 and Dash Command say my idle at 167 degree coolant temp is 750 and stable but
still rough and with AC on drops to 725 then picks back up to 750 but rougher than it should be.
So what am I missing ? How do I get the idle back to 800 and smooth?

Right foot(insert smart ass emoji)