Lack Of Top End Performance

[FamilyWagon]

Hi all,

 

After my recent spate of dealer intervention - they changed the main power boot relay due to intermittant failure and they reset the ECU, I seem to struggle a little to get past 70mph in 5th gear. Where as the Galaxy would easily cruise up to and beyond 70, I seem to have to make the engine take me to this speed and the accelerator is almost planted to the floor.

 

The only other thing I have noticed is that the engine seems to be a little...well how can I say... lumpy...not as smooth as it was before all this happened in all gears.

 

Please could someone tell me the most likely culpret so I can go to the dealer with a list of things to check as the car is still under warranty.

 

I was thinking maybe the MAF is on it's way out, but don't these normally go on the TDI's? Or is this fault also common on the petrol engines? If it is the MAF does it log a fault code?

 

If it is not the MAF does the Gal need new air filter, plugs and leads?

 

Many thanks,

[Andrew T]

You do have a MAF, but not the same type as that on the Diesel. It costs about

[El Dingo]

Andrew is right - something has been disturbed, maybe in the ECU/engine management.

 

It could be MAF...

 

If the engine is lumpy it would suggest that you still have engine management issues... Or maybe a dodgy coil pack? Be careful as this kind of thing can damage the cat.

 

A lack of power suggests poor fuelling at higher engine speeds or weak ignition. Another problem could be a blocked up cat (partially blocked exhaust) - give the exhaust a gentle punch - does it rattle/sound like it's full of loose bits.

 

But all this is guesswork. I wonder what a diagnostic plug-in would show up?

[FamilyWagon]

Thanks for your replies.

 

If I take the Gal to the main dealer and tell them the symptoms, would they have the ability to conduct an accurate performance test, maybe on a dynamo or something like that as opposed to just getting one of the mechanics to take it out for a burn? - which they did when it went in last time.

 

The thing is, I know how the Gal drove before they changed things and it is definitely different now - the change is very slight but it has changed all the same. All they will want to do is see if there are any error codes and if not then they will tell me that all is fine - but it is not.

 

Thanks for all your help.