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Tintop problem
Humbug - 27/2/07 at 11:37 AM

1999 VW Passat estate 1.8 petrol (non-turbo)

Symptoms: feels like driving with the handbrake slightly on, i.e. for any given speed, have to accelerate more and/or be in a lower gear.

Latest: going along the motorway with a steady throttle pedal, it will suddenly slow down a bit (say 5mph) for 5-20 seconds, then speed back up again.

Any ideas for things I could check before paying someone to clock up hours of investigation time?

Cheeyaz

macnab - 27/2/07 at 11:42 AM

have you checked if any of the wheels are getting hot. A sure sign that a brake is binding.



[Edited on 27/2/07 by macnab]

locoboy - 27/2/07 at 12:12 PM

Fuel pressure regulator/pump, possibly not managing to maintain pressure or regulate pressure consistently.

westf27 - 27/2/07 at 12:43 PM

blocked exhaust?

bartonp - 27/2/07 at 12:46 PM

Forgot to unhitch trailer? (Look in rear view mirror)

MikeR - 27/2/07 at 12:48 PM

if its light throttle, idle valve playing up / throttle body covered in oily deposits - i'm amazed the difference cleaning mine has made.

lambda sensor sending poor readings (although i'd expect the engine management light to be on for this)

I'd be tempted to agree with the fuel pressure suggestions.

If it was BMW i'd say when was it last serviced, heard from this forum that the engine automatically reduces power as it gets close to (or maybe goes past) service time.

russbost - 27/2/07 at 01:14 PM

Believe they are known for tps (throttle position sensor) problems, will cause slight hesitations, delayed pickup as throttle is applied - if it's this should always happen at around the same throttle openings but will not be revs dependant.

Humbug - 27/2/07 at 01:41 PM

quote:
Originally posted by russbost
Believe they are known for tps (throttle position sensor) problems, will cause slight hesitations, delayed pickup as throttle is applied - if it's this should always happen at around the same throttle openings but will not be revs dependant.


Thanks all for the suggestions. Russbost - this sounds like the symptoms I am seeing - happens when I have the throttle pushed a fair way down, i.e. when accelerating, or when maintaining cruising speed. I will give the wheels a check just to see if it's the brakes, then back to the garage.

Edited to say that no warning lights are on

[Edited on 27/2/07 by Humbug]

britishtrident - 27/2/07 at 02:09 PM

Classic Fuel flow problem symptoms, ---- pump, filter, regulator, blockage in line, free floating debris in tank.