Passat - John
Recently posted another thread here before and i was wondering if theres any help for another problem ive got for my Passat. The rev meter seems to go up and down just slightly everytime the car is at a stand still, what would cause this problem and whats the fix!??

Thanks in advance
Re: Passat - mike harvey
Known as hunting in the trade. Possibly faulty idle speed control valve, depends on how old the car is, petrol or diesel, which fuelling system?
Mike
Re: Passat - John
Its a S reg, petrol 1.6, how much do u think it will cost to fix??? It only has 13,000 miles on it! Does anybody know how this is caused???
Re: Passat - Andy Bairsto
Passet 1.6 are plagued with problems ,the ecu ,injection system and many unknown other problems they are called garage cars in Germany.If you get it to run properly call VW they would love to know how you did it
Re: Passat - honest john
This might even be normal as the ECU adjusts the engine speed to maintain a clean emission idle.

HJ
Re: Passat - John
While the cars at a standstill,and the revs meters doing that, the gearstick is also shivering and that shouldnt happen
Re: Passat - Bill Doodson
John

All rotating equipment, which includes the engine in your Passat has a critical rev range. This is a range of revs that causes vibration far higher than you might expect for the engine speed. All of the components in your car also have a critical or sympathetic vibration mode. If your engine has a critical vibration that matches your gear sticks sympathetic vibration then it WILL vibrate. When I was an engineer in the merchant navy many of the motor ships I sailed on had signs saying "don't run this engine between say 68 and 71 revs per min or 89-95". At these speeds these engines could cause themselves major damage in a short period of time. This was easily demonstrated by the amount of stick (throttle) that you had to put onto the engine to quickly get it through the critical revs. The NVH Engineers (Noise Vibration and Harshness) at all of the car companies spend a large amount of time tuning cars so that this doesn't happen at speeds where it would detract from your driving, at idle its just a small annoyance.

By the way large marine diesels DO run at speeds from 14 to 120 rpm. Their thermal efficiency knocks the newer car diesel engines into a cocked hat. A TDI Passat doing 50 mpg on a run would I guess do 75 if it had a similar efficiency. I will be happy for more upto date folk to contradict me on this.


Bill
Contradictions. - David Woollard
Contradict the "genius and master architect", I think not.

David
Re: Contradictions. - Bill Doodson
David,

I was waiting for someone to spot that one. It was one of the reasons I moved to NTL, everyone else seems to have an embargo on using greek mythical names. But them I am an Engineer, not so much the Architect, it depends on which translations are used I suppose.

Bill
 

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