996 Idle Issue

[kj217]

at traffic lights, the rpm goes down to 200 rev for a second or two then the idle goes back up to normal.

i have cleaned throttle body and MAF but didn't fix it.

my car is MY00.

What is this?

Edited April 15, 2010 by kj217

[Loren]

have you checked for fault codes? You may have an air leak or a bad MAF.

[kj217]

have you checked for fault codes? You may have an air leak or a bad MAF.

there is no CEL,, do i still have to check the codes?

i have once unplugged the MAF and the symptom popped up again,, i guess this eliminates the MAF,, and the leak,, right?

Edited April 15, 2010 by kj217

[Loren]

Yes, you could have pending codes and if your scan tool allows it check to see the MAF voltage. It should be stable at idle and increase with RPM.

[kj217]

Yes, you could have pending codes and if your scan tool allows it check to see the MAF voltage. It should be stable at idle and increase with RPM.

some said that my AOS is going out,, what do you think?

i tried once to remove the oil filler cap while the car running,, didn't stall but it idled roughly,, is that something??

what is the ideal idle rpm? mine idles @ around 700,,

[Loren]

Could be - the pending codes would say if you have an air leak and the MAF test would say if your MAF is bad.

[kj217]

Could be - the pending codes would say if you have an air leak and the MAF test would say if your MAF is bad.

Is there anything else can cause this problem?

[Loren]

I asked you to look at the codes because they will tell what is going on. That along with other built-in tests give techs an idea what is going on. That is why Porsche put the faults and test measurements in the cars.

Anything else (without the diagnostic facts) is frankly just a wild guess.

Most people would look at a car with a flat tire and say 'you need a new tire'. A good tech would say 'lets look at the tire, the wheel, and valve - and find out what is the real fault cause'.

We try to give educated and analytical answers here - we try NOT to guess.

End :soapbox:

[kj217]

sorry i for the tons of questions,,

I needed help since my local dealer doesn't seem to be helpful on this,,

Thanks.

[kj217]

an update,,

i took the car to the dealer,,

they found no codes,,

cleaned the MAF,,

reflash the ECU,,

checked all possible causes,,

chraged me $200,,

later at the same night the car was out,, it happened again and the RPM dropped to 200 revs and back up again,,

i am out of ideas,, please, please, help!

:@

[phillipj]

Loren,

The 2000 996 is e - gas so there is no idle valve.. Is that correct?

[Loren]

Loren,

The 2000 996 is e - gas so there is no idle valve.. Is that correct?

Correct.

My guess is he still has a dirty throttle - likely behind the butterfly.

If not I guess it could be an intermittent throttle positioner - which would mean a new throttle body.

[kj217]

Loren,

The 2000 996 is e - gas so there is no idle valve.. Is that correct?

Correct.

My guess is he still has a dirty throttle - likely behind the butterfly.

If not I guess it could be an intermittent throttle positioner - which would mean a new throttle body.

i have removed the throttle body completely that day to clean it inside out,,

is there a way to test the positioner?

how much is the TB?

[Loren]

You can test the postilioner with a PST2 or PIWIS tester - not sure about Durametric.

997.605.115.01 Throttle body -- US MSRP $324.04

[kj217]

i tapped the issue for a clear view:

http://www.youtube.com/watch?v=4Taz4CJiSnw

my local stealer still can't do anything with it :(

Edited April 29, 2010 by Loren
made video viewable here

[philooo]

any news on this problem ? did you solve it ?

it sounds really close to my problem here

[kj217]

any news on this problem ? did you solve it ?

it sounds really close to my problem here

mine is solved already,,

it was the fuel tank breather valve going out,,

my car never stalled under any condition,,

your problem sounds like a dirty throttle body or an intake vacuum leak somewhere after MAF toward the engine,, check the air intake pipes and manifold gasket,,

there is a slight possibility that the excess oil has reached areas further than the throttle body where they may easily reduces the air flow to the engine,,

if possible,, take off and clean throttle body, MAF, air box, intake pipes and manifold,,

keep us posted,,

KJ