Fed up.....opinions invited.

[SKOOSH1970]

Good evening all, I wonder if anybody could shed some light on an issue with my 2008 tfsi cab.

Recently she started over revving at idle , sometimes upto 1200rpm in neutral, and the CEL would come on and stay on but I wouldn't notice any huge differences in performance as she was smooth and pulled strong. I plugged my basic diagnostic reader in and found no fault codes so I cleared the CEL, all good for a few days. It started again, so, after much research I decided to change the coilpacks to new red "R8" type , new pcv valve and gasket and still no change. Today, after more research, I bought and fitted a new bosch N80 purge valve, cleared the CEL and started her up. Initially she idled very lumpy but at 800rpm and after a while, settled down, excellent I thought.

My drive home from work is a 30 mile journey on A and B roads and all was well until a few miles from home and yes, you guessed it, CEL came on again and revs erratic at standstill. I've plugged her in again, found NO codes, reset the CEL and all seems ok apart from she feels like she' searching for revs.

Please somebody offer me some words of advice, besides plugging it into a proper diog reader as I need to try and sort it...!

Thanks in advance and anticipation.

Si

 

[Metalsmurf]

Mine was doing this. Sounds like a vacuum leak. My oil dipstick wasn't fully in. Silly really. Could be anywhere in your lines really. YouTube finding vacuum leaks. Could try a new pcv and diverter valve. You need it plugging into a proper code reader really.

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[Beardymat]

I got a PCV valve off ebay which started out okay but then displayed the symptoms you're having, changed the valve for a genuine one and problem was solved. The valve was supposed to be oem quality but clearly wasn't, It's so easy to sit at home in your underpants and click buy it now and have it delivered to your door but it's a habit I'm kicking!

 

[Charlie Farley]

Your best plan would be to get vcds run on the car , that way you can get a more indepth overview on what is actually going on, basic code readers are just that, basic , to get a more indepth starting point you need to run vcds and see what the log has stored in terms of errors etc and also a realtime over view.
One can just keep on second guessing what the problem is and never get to real cause and never resolve the problem.

 

[SKOOSH1970]

Chaps, thanks for the replies........ it appears that after replacing all the parts that I did without improvement, I needed to give the MAF a really good clean with carb cleaner..... no lights, no judder and a nice 800rpm tickover.

 

[Metalsmurf]

I've just ordered a new pcv and DV. My CEL comes on sometimes. When they arrive I'm gonna fit them and clean the MAF also as you suggest. Not bothered which is the actual fix as I don't think they've ever been replaced anyway. Thanks for actually finishing a question with an answer dude.

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[Metalsmurf]

Chaps, thanks for the replies........ it appears that after replacing all the parts that I did without improvement, I needed to give the MAF a really good clean with carb cleaner..... no lights, no judder and a nice 800rpm tickover.

Quick question and it might sound stupid but how did you clean the MAF. I looked and it looks pretty enclosed when it's removed from the intake pipe.

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[Ash_mtb]

Cant you remove the sensor from that housing? Ive gota clean mine too

 

[SKOOSH1970]

Chaps, false alarm, cel came on again, reset it and she's idling rough but revs hold at 800rpm. She's being plugged in properly in the morning but as she's running so ****** smoothly I suspect a minor issue but will post the outcome.

With regards to reoving the maf, it's only 2 fixings and 1 connector. Remove, spray liberally with carb cleaner, allow to dry for a few minutes and refit.....simple task.

Si

 

[SKOOSH1970]

Morning all, right, had a proper diag test this morning which revealed 2 fault codes....00051 and 08583.......let my searching begin.......!!!!

 

[SKOOSH1970]

I got a PCV valve off ebay which started out okay but then displayed the symptoms you're having, changed the valve for a genuine one and problem was solved. The valve was supposed to be oem quality but clearly wasn't, It's so easy to sit at home in your underpants and click buy it now and have it delivered to your door but it's a habit I'm kicking!

Bang on advice....... bought Audi part, fitted and she now runs sweeter than she's ever run.... !!!!

 

[Charlie Farley]

Get rid of the PCV altogether and it is even better.....