View Full Version : Air Flow meter

05-11-2007, 02:18 PM
I have a 1996 Passat tdi which will not rev beyond 3000. If revved to the max when stationary 3 or 4 times in succession it throws out a lot of thick black smoke and then will not run properly - but I switch off and start up again it is perfect. Mpg is good. I have been told all different things by garages ranging from a faulty air meter or turbo. A diagnostic showed everything was all right although I noticed the air mass meter reading went haywire briefly which the garage said was nothing to worry about and they reckoned the turbo was leaking oil internally. The car can also sound very throbby Can anybody help

07-11-2007, 11:33 AM

You can usually check if the air sensor is the problem, just unplug it's electrical connector, and drive the car. It should run ok but with less power than normal. This is 'limp mode'. The engine should rev past 3000 no problem in lower gears, but may struggle a bit due to reduced power.
Where are you located, some american cars had an extra injector at the catalyst, this fires to increase the cat temp, but can also cause smoke?

10-11-2007, 09:04 AM
Thanks for your time - I`ll try that