# Rough idle no CHECK ENGINE LIGH!! grrr



## BIHrocco (Aug 13, 2003)

So here is the deal, my 1999 audi A6 had a bad water pump, I purchased, timing belt, tensioner, idler, waterpump, and thermostat.... i used a OEM timing belt alignment tool along with the crank pin lock tool.... a case of beer and started dismantling the front end... when I turned the crank to align the timing mark with 0, i noticed the camshafts did not align, the passanger was dead on, but drivers side was off by a tooth or 2... i also noticed the timing belt was very loose so I figured hey maybe the slack cause it to look OFF, or it might have jumped a tooth no big deal. 
long story short I changed all the components and put the new belt on, spun the engine over a couple times to ensure proper belt seating... reasembled everything and fired her up... the car took a while to start like it was flooded... blue smoke came out of the tailpipe in the beggining (probbably from sitting, I got in to the car for a test drive and noticed the car was idling very rough like a constant missfire.....
i checked all the sensors to ensure I plugged everything in... went back inside and drove around the block, suprisingly the car drove better than before the timing belt change, not sure why, it ran smoother and it felt like way more power... but the rough idle was still there... I drove around hoping the check engine light would come on but nothing... 

its been 2 days now and no check engine light, the car runs very good if the RPM is above 1000, but anything below it shakes... 

my question is if for some reason the cam alignment was set wrong by one tooth would the symptoms match mine?
also if anyone else has experienced something similar to this what should I look at... I checked all the vacum lines, checked all the wires for spark even at idle and pulled all the plugs they all seem to be in good equal condition.

thanks


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## Slimjimmn (Apr 8, 2006)

*Re: Rough idle no CHECK ENGINE LIGH!! grrr (BIHrocco)*

The cams never come into alignment perfectly, you usually have to put it in one cam and then push down (or up) to lock it in the other cam. The 2.8v6 engines have a lumpy idle, its normal even new ones with 10miles idle like that.


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## BIHrocco (Aug 13, 2003)

*Re: Rough idle no CHECK ENGINE LIGH!! grrr (Slimjimmn)*

the weird part is it started doing this after timing belt... no check engine light


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## mwebb (Apr 19, 2008)

*Re: Rough idle no CHECK ENGINE LIGH!! grrr (BIHrocco)*

[color:blue] scroll through ADvanced measuring blocks and look for test 094 
IF there is a value in one of the fields that shows "test Off" 
IF there is no "test off" in the 094 measuring block , ignore this , it does not apply to your engine 
then get to 04 basic settings and run 
- basic settings test 04 094
and the other 04 basic settings test for the intake cam range 
=======================================
what are the values in 
Measuring block 032 ? 
what was intake vacuum at warm idle before and
what is intake vacuum at warm idle now ? [/color]


_Modified by mwebb at 6:16 PM 5-25-2009_


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## jollespm (Aug 18, 2000)

*Re: Rough idle no CHECK ENGINE LIGH!! grrr (mwebb)*

I've been battling similar problems with my 2002 Passat. I noticed that when I forgot to connect the PCV connections up, the car idled very rough, but seemed fine at higher RPM. Maybe check all the connections? Especially the one hidden under the throttle body.
Now if only I can figure out the camshaft position sensor error and misfires I've been getting...


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## Slimjimmn (Apr 8, 2006)

*Re: Rough idle no CHECK ENGINE LIGH!! grrr (jollespm)*

what is the cam code? IS it cam position sensor fault, or cam shaft b1, b2 out of adjustment?


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## mista808 (Apr 30, 2000)

Try cleaning the throttle body with some cleaner.. I mean, taking off the intake tube and get in there with a shop towel and cleaner and get down... have someone step on the pedal for you and clean as much as you can around the butterfly. I had this similar problem. There is actually a TSB for this problem, it happends when over time dirt builds up in the throttle body, so the computer has to constantly program itself to compensate in trying to keep the idle at the right speed. When you disoonnect the batter, that memory gets whipped out and now you gotta reset with a, what the dealership calls a "basic setting"... but to get around that just clean the TB really good.... my 2.8 avant runs a whole lot better since I cleaned mines....


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## BIHrocco (Aug 13, 2003)

*Re: (mista808)*

the codes were (bank 1 rich and bank 2 rich) the thing is since I cleaned the maf and the TB it would sometimes work, sometimes wouldnt, and funny thing is I cleared the check engine light because I needed to pass emissions here and drove it like that for 2 days without triggering the light, and was able to pass emissions. 
but not even 2 minutes after emissions the light came back on (i got lucky), now the car idles super bad, and i have smelled the burning/rotten egg smell before at idle, so I got a new MAF and still the same. wtf? 
also the auto transmission goes into LIMP mode and stays in 3d gear, if I scan the transmission it gives me a code saying the ECU Sent the wrong VALUES.
i will get the exact codes later today.


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## BIHrocco (Aug 13, 2003)

*Re: (BIHrocco)*

so I found these on my computer trying to find the saved codes, anyone see anything wrong?


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## Slimjimmn (Apr 8, 2006)

*Re: (BIHrocco)*

yea, 10.2 gm/s is WAYYYYYYYYYYYYYYYY to high for maf sensor flow at 700rpm. you should see 10.2 @ about 1500rpm. Normal idle gm/s for the maf sensor at idle is about 2.8-3.8gm/s. I would say either you have a pretty good vacuum leak after the maf sensor, the timing is off on the intake, or the maf sensor is bad.


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## BIHrocco (Aug 13, 2003)

*Re: (Slimjimmn)*

well the thing is I put in a new MAF OEM and the numbers got higher at idle??????????? and it runs extremely rich, to the point where if i run it for a minute it smells like rotten eggs, but if I drive on the freeway with keeping the rpm higher it runs good, no smell, no check engine light, its when I slow down that I get a check engine light for RICH-Bank1 and Bank 2, I guess i will try another MAF.


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## webster426 (Jun 23, 2009)

Where do you get VAG-COM?


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