2.7taudi

scanned my car today and got some misfire codes: 2001 a6 2.8 FWD 97k
2 Faults Found:
16684 - Shareware Version. To Decode all DTCs
P0300 - 35-10 - Please Register/Activate - Intermittent
16689 - Shareware Version. To Decode all DTCs
P0305 - 35-10 - Please Register/Activate - Intermittent

ROSS TECH DEFINITION: 16689/P0305/000773 - Cylinder 5 Misfire Detected
16684/P0300/000768 - Random/Multiple Cylinder Misfire Detected


it says something about camshaft position is this timing belt related? i got the belt changed professionally at 89k the car now has almost 97k. if it was timing belt related would it take 8k miles to detect it?

i changed the spark plugs at 75k but the mechanic i got it changed from said the cheap plugs would be OK to use so he bought some cheap copper ngks single tips i believe. i havent been back to that mechanic after he changed the plugs and did not get my belts replaced by him.


the car runs like normal no loss of power no check engine lights. i just scan my car every week to see.

last month i had 16825/P0441/001089 - EVAP Emission Control Sys: Incorrect Flow
but i cleaned the purge valve and lots of black crud came out and the code went away.

i also had the code (last month) 16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold
but i was low on oil so i thought since i park on a steep hill the oil went into the cats and blocked the holes. so i started parking it in my garage and after a long drive the code was gone (and used some stp fuel injector cleaner) AND i had the oil was only 2k old and i changed it my self and made sure it was full multiple times but it became low and i had to add about 700ML. the oil could not have been lost from leaks because i had my leaks fixed.

i wrote my old fault codes so maybe someone can make a connection (if any?)

ALSO since the code was intermittent is it OK to drive the car? i drive the car to work which is 5 miles away and 5 miles back. ill be using my 2.7 for long trips for now.

ALSO noticed when i started the car from cold the rpms were bouncing around 100rpms for a couple of seconds and then normal. i read a thread that a guy fixed his P0300 by replacing the oxygen sensor. this doesnt seem like it would help to me what do yall think?

2.7taudi

update: from this morning i drove the car 40 miles and i just now scanned it again and no fault codes were found. does this mean the ecu just tripped a code?

so in cylinder 5 the misfire i had i can rule out the timing belt issue or it would have caused the whole bank to misfire i think. if the code comes back im thinking its probably a bad spark plug or the wire from the distributor cap to the plug (coil pack?) or maybe a dirty injector.

But what does the p0300 mean? does it mean all the cylinders are misfiring? if it does why would it just specify cylinder one and not the others?

i could use any help. car is at 97k and this is the 1st misfire.

ezveedub

P0300 always shows up when a misfire is detected, so in your case, its P0300 and P0305. It will have the P0300 and what ever cylinder is detected to have a misfire.

jseklund

If the codes are clearing themselves, and the car is running fine...it's tough to say if you even have a real problem.

90% of the misfire codes we see on these boards are related to coil pack failures...move your coil pack from cylinder 5 to another cylinder and see if the misfire code changes to whatever cylinder you put it on.

If you never get the code again....it could be hard to tell.

I don't know if you can do this with the free version of VCDS but if you had the full version you could look at the mifires as they occur. They don't always trip codes if they are not severe. On my mom's 2.7T I recorded around 50 misfires on one cylinder once with no codes even being stored. Seeing if it's just one cylinder misfiring or a couple will give some more insight maybe...

rsadamsB5

My car is missing aswell under load. The only codes i pull are EVAP codes could this cause misfire???? I changed the coil pack, wires, and plugs 2000 miles ago.

2.7taudi

I think i can check the misfire on the free version but ill have to check which group its in. in the free i can check from group 1-25. i recall seeing it before but never paid attention because i didnt have the problem lol.

But the code did not clear themself. i cleared it with the vag and scanned it after driving it for 40 miles and the code did not come back.

2.7taudi

Oh ok so the p0300 will show up under any misfire.
so when rosstechs def is multiple misfire i only have one misfire which is cylinder 5 correct?

i will be changing the plugs this weekend and hope it fixes it.

thanks for the help everyone!

jseklund

The plugs probably aren't the problem, but it's a start. The coil pack is the first place I'd look. Just pop the coil pack off of the misfiring cylinder and move it to another. If that cylinder starts missing, you know it's the coil pack.

I belive it's group 15 and 16 in the VCDS.

2.7taudi

alright i will check that out and report back! thanks for your help.

4Driver4

The 2.8 does not have individual coil packs.

My guess is valve cover gasket leak into the spark plug wells.