MAF sensor, knock sensor....???

chris039

S3-A quality driving experience
Joined
Jan 27, 2008
Messages
6
Reaction score
0
......or just a coil pack!!!!

I recently had trouble with my S3 running rough almost misfiring, after vag-com pointing towards maf sensor and knock sensor i decided to start with the first, after replacing the mass air meter with a genuine new one i found no difference.
Back to basics, stripped the engine covers and checked all pipe works for leaks to find nothing.
After getting my mate to look at it with a fresh set of eyes he sugested checking coil packs, un-plugging one by one hey presto un-plugging number 3 made no difference!!!

Lesson of the day.... use vag-com as a direction not a diagnostics. :)

oh and if anyone needs a MAF sensor i have a cheap one going!! :happy:
 

SiGainey

Registered User
Joined
Sep 29, 2003
Messages
491
Reaction score
13
......or just a coil pack!!!!

I recently had trouble with my S3 running rough almost misfiring, after vag-com pointing towards maf sensor and knock sensor i decided to start with the first, after replacing the mass air meter with a genuine new one i found no difference.
Back to basics, stripped the engine covers and checked all pipe works for leaks to find nothing.
After getting my mate to look at it with a fresh set of eyes he sugested checking coil packs, un-plugging one by one hey presto un-plugging number 3 made no difference!!!

Lesson of the day.... use vag-com as a direction not a diagnostics. :)

oh and if anyone needs a MAF sensor i have a cheap one going!! :happy:

PM me about how much you want for the MAF sensor :)
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
Joined
Sep 14, 2008
Messages
24,813
Reaction score
6,048
Welcome to the world of diagnostics my friend :)

VAGCOM is a great tool but as you have found out faults found by it aren't always true faults but the result of another fault that may not always be picked up...

Lesson to anyone here using VAGCOM is to interpret the results and think logically about them...

Interested to hear what made you think it was the MAF... did it throw a fault code or was the airflow readings low when you logged?

<tuffty/>
 

Welly

335D Driver :-)
Joined
Aug 5, 2009
Messages
10,703
Reaction score
141
......or just a coil pack!!!!

I recently had trouble with my S3 running rough almost misfiring, after vag-com pointing towards maf sensor and knock sensor i decided to start with the first, after replacing the mass air meter with a genuine new one i found no difference.
Back to basics, stripped the engine covers and checked all pipe works for leaks to find nothing.
After getting my mate to look at it with a fresh set of eyes he sugested checking coil packs, un-plugging one by one hey presto un-plugging number 3 made no difference!!!

Lesson of the day.... use vag-com as a direction not a diagnostics. :)

oh and if anyone needs a MAF sensor i have a cheap one going!! :happy:

In fairness, a misfire will cause knock from the engine. And that MAF sensor error could have been a historic one. Did you reset them first and then drive it to see what came up?
 

Welly

335D Driver :-)
Joined
Aug 5, 2009
Messages
10,703
Reaction score
141
At least it's fixed though! :thumbsup:
 

chris039

S3-A quality driving experience
Joined
Jan 27, 2008
Messages
6
Reaction score
0
Hey guys been away for a while so not been on here, I did reset the codes and drove the car which kept throwing up MAF sensor faults as well as knock sensor, dissconnecting the maf meter should resort back to standard settings, however this didnt happen but i could get one readily available so thought worth a try and loads of threads on how they are tempramental made go stab in the dark and give it a try.
Anyhows, back to the basics fixed it in a short time so im happy and i'll get rid of the MAF meter and sort a sticking hydraulic lifter.
 
Top