aux water pump buzzing

[Roger Blassberg 0]

My word, Craigowl !! That is a very tidy looking under-bonnet appearance - unless you just polished that corner for our benefit.

 

Best wishes

 

RB

[craigowl 0]

Thank you, Roger, ever the gentleman. :)

I really need to get out more in the C.

[Supercharged 2]

I really need to get out more in the C.

 

Clearly you do! - drive down to the summer scorcher!

[herisites 0]

Ok guys, really want some help and advice please as im really worried!

 

My heater matrix blew last monday and so i had to run the car with it bypassed all week. This weekend i replaced the heater matrix with a genuine valeo one (what a BASTARD of a job :shock:). Now obviously i DO NOT want to have to replace the matrix again so i want to find out what i need to check on my car to make sure everything is running as it should do and wont blow my nice new matrix again or anything else for that matter. How would i know if my aux pump has seized? As this is what im worrying about now!

 

I dont know if this is dodgy but im pretty sure it is, after replacing the matrix we re-filled and coolant and bled it through getting the car up to full heat with the heaters on etc. The radiator fans kicked in a couple of times as we were bleeding it. But one thing i noticed when i went back in the car was that my heaters started off hot like they should but they cooled down again when the engine was really hot, even though they were still set to hot. It shouldnt do this should it? The heaters should stay hot once hot right? What could this be?

[craigowl 0]

Aux pump.

If you switch off engine when it is at working temp, then switch on ignition, but not enuf to start engine, you can normally hear the aux pump start, whirring and gurgling a bit as it does so, even from inside the car in the driver's seat.

The fact that the aux pump is not working is not as serious as your other potential problem IMO - my pump had not been working for an unspecified period - perhaps weeks, perhaps years - but I never knew until I saw blown fuse and replaced it.

(i never had any temp or overheating problems to give me reason to suspect anything was wrong with the cooling system, but then I dont abuse the engine.)

 

Cold heater matrix

Im not an expert, but I would say you have air in the matrix now. Presumably an air lock has worked its way round the cooling system and into the matrix.

 

Others on the forum know a lot more than me. with luck, they will come in and advise.

Good luck.

[RS VR6 0]

That VW aux pump is the biggest piece of crap ever. My brand new one failed in less than three years. Before it completely seized up...it sounded like it was grinding coffee.

 

Here is what it looked like.

 

From the looks of it, the grinding sound came from the loose impeller shaft...then it siezed when the shaft broke off. :fist:

 

I guess I got lucky when I found a new one for 50usd shipped.

[LukeManic 0]

Well I have now successfully changed mine :D , with the help of this forum though I wouldn't have been able to do it - I'm going to make a donation when I get home from work tonight.

 

RS VR6 - thats excatly what mine sounded like, not very nice.

 

Cheers all.

[Toad 0]

Had a thought over the weekend.

 

There are two fan controller units for the corrado, and early unit with one 50amp fuse and a late unit with the 50amp fuse and a 5amp and 20amp.

[herisites 0]

Aux pump.

If you switch off engine when it is at working temp, then switch on ignition, but not enuf to start engine, you can normally hear the aux pump start, whirring and gurgling a bit as it does so, even from inside the car in the driver's seat.

The fact that the aux pump is not working is not as serious as your other potential problem IMO - my pump had not been working for an unspecified period - perhaps weeks, perhaps years - but I never knew until I saw blown fuse and replaced it.

(i never had any temp or overheating problems to give me reason to suspect anything was wrong with the cooling system, but then I dont abuse the engine.)

 

Cold heater matrix

Im not an expert, but I would say you have air in the matrix now. Presumably an air lock has worked its way round the cooling system and into the matrix.

 

Others on the forum know a lot more than me. with luck, they will come in and advise.

Good luck.

 

Cheers for that. I thought maybe an air lock as well so we just kept on running the engine hot and adding more and more water whilst squeezing the radiator hoses to get rid of as much air as we could.

 

If the aux pump is seized would the fuse be blown? I checked the fuses you shown on the previous page and both are fine. Any others i should check?

 

Also from searching would mine have a heater matrix bypass valve or do new ones have it built in? When mine went my passenger footwell got wet and im led to believe the bypass valve is supposed to stop this happening?

[Kevin Bacon 5]

That VW aux pump is the biggest piece of crap ever.

 

They're not the best. An offboard Mezieres pump would be much better.

 

My brand new one failed in less than three years. Before it completely seized up...it sounded like it was grinding coffee.

 

Indeed. Mine often needs a thump to shut it up. Thinking of binning it altogether tbh....

[craigowl 0]

Herisites

 

Aux pump and 5amp fuse.

I am not an expert on electrics, but I guess such a low amperage fuse would have to blow when the pump's electric motor labours or seizes.

 

Matrix bypass valve.

Dont know about this, sorry.

[RS VR6 0]

Got this off the Vortex 12v forum.

 

[i:e4198]"In addition, an Auxiliary Electric Coolant Pump also circulates

engine coolant anytime the ignition is switched on.

 

The Auxiliary Electric Coolant Pump also runs when the engine

is switched off and the coolant temperature goes over 107