Hi all,
Am currently having my 60k mile cambelt change on my 03 Passat PDi. I have just received a call from the garage to inform me that I need a new viscous fan pully bearing (I think that is right?). Could someone explain what this is and why I might need a new one? Or whether the guy is making things up!
Thank you in advance.
R
Edited by Dynamic Dave on 19/11/2007 at 12:30
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The 03 Passat PD Tdi (& Skoda Superb ) has a mechanically driven cooling fan driven by the fan belt via a viscous heat controlled clutch mechanism so that the fan doesn't spin much when cold. If the pulley (the bit driven by the fan belt) bearing has failed then YES it does will replacing.
You need to make sure that you are having a full cambelt kit fitted complete with belt & pulleys. A replacement water pump(driven by cambelt) whilst you are passing can also be a good idea.
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Thanks Big John,
The garage in question has up until now always been pretty good. They service all our vans etc for work. I figured I would have to bite the bullet and pay for it to be replaced. All the belts and pulleys are being replaced for the cambelt change (apparantly they all come in a kit now anyway - not as individual items). Annoyingly I asked for the water pump to be changed but they haven't done it as there was no note of it on any of the paperwork and it would involve having to take the cambelt off again. Not good. I guess it would be okay to leave it until the next cambelt change, though not ideal?
Cheers
R
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As I said on a recent post, my Passat TDI 100ps water pump was changed for the first time at 105,000 miles. No visible deterioration when I looked at the pump- garage only changed it reluctantly at my request.
The tensioner damper WAS in a bad way though.
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Be careful of model years - the early PD engines had hopeless tensioners - a 2003 PD will have the later (better) friction damped type.
Whilst I'm obviously pleased that your water pump was undamaged (and hope you don't mind the cost of its replacement), their track record is not good. I have known the plastic impeller to either come loose on the shaft or break up at fairly low mileages. Rozza - as yours has not been changed, keep an eye on the coolant thermometer. It climbs very rapidly as the engine is revved if the impeller is loose.
659.
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"the early PD engines had hopeless tensioners "
Well until I spotted this on my car , no one had mentioned the potential problem on this site. The water pump problem was pointed out to me several times.
So what other secret well known problems are there? ;>)
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Problems with cars come to light as they get older - time and mileage are great testers of a good design.
659.
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Thanks for all the replies. Just another quick question. What is the potential likely damage of a water pump failing and is the temperature guage the only way to tell whether is has gone/ or is on it's way out.
Thanks
R
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If the pump impeller breaks up, the pump can seize solid and strip teeth from the cambelt which drives it. This then causes expensive engine damage. If the impeller does not jam but either breaks up or becomes loose on the water pump shaft, the engine will overheat.
Due to the wonderful thermal efficiency of the PD engine, not a lot will happen at low revs but the coolant thermometer will climb rapidly as the engine is loaded at higher speeds (more fuel = more heat produced). If you keep an eye on the dashboard gauges you should spot this, but there is always potential for engine damage in these cases.
I have been told (no first-hand experience) that the heater output becomes erratic when the pump impeller is loose - not even the gizmology of the climatronic can compensate for this.
659.
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