Volkswagen Passat - Acceleration goes down on motorways

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Tue 13 Mar 2012 14:00
Volkswagen Passat - Acceleration goes down on motorways - asim

My VW PASSAT S TDI drives well around town but when I go on motorways, specially if its uphill, you feel a clear damp in the acceleration as someone has applied brakes on it and then its just no power in the engine. I put my foot down on the floor and it takes ages to get from 60mph to 70mph and it doesn't go above 80mph, I remember it has gone up to 120mph and the engine use to give a nice whistle like sound when I use to accelerate hard but not any more.
I noticed 1 pipe going from the MAF meter to the engine that was broken, I repaired it and it worked well for a few days but now I am having the same problem again.
According to my mechanic its the turbo or the clutch thats gone but I dont believe that as the car drives well around town.
Any idea what it could be?

Reply | Report as offensive | Link
Tue 13 Mar 2012 14:51
Volkswagen Passat - Acceleration goes down on motorways - craig-pd130

How was the pipe from the MAF meter broken, was it split? How did you repair it? Sounds like the repair has sprung a leak.

That's the main inlet air duct, if there's a split / hole after the MAF it will throw the fuelling right out because the engine management computer will not be able to accurately calculate how much air is going in.

Repairing the inlet pipe is really only a temporary measure, it needs replacing. I'd try another mechanic, too.

Reply | Report as offensive | Link
Wed 14 Mar 2012 09:48
Volkswagen Passat - Acceleration goes down on motorways - asim

Thanks Craig-pd130

I dont know how it broke but I believe it was during the service because this problem started right after the service and I noticed it a few days later and put a tape around it which worked well for few days but I think I should take your advice to change the whole pipe and will let you know if it worked.

Thanks

Reply | Report as offensive | Link
Tue 13 Mar 2012 16:32
Volkswagen Passat - Acceleration goes down on motorways - ChannelZ

Replace the fuel filter.

Reply | Report as offensive | Link
Tue 13 Mar 2012 22:37
Volkswagen Passat - Acceleration goes down on motorways - Avant

Moved to Technical.

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide