Aux Water pump

[Dub Style 0]

I know the aux water pump is there for a reason system design etc. What if it was removed, the reason i say this is when the pump on my vr was connected the temp would climb in traffic and generally be higher. Now when i changed my coilpack i noticed that the plug for the pump may have broken at some time and somone put two spade connecters to make em fit so i disconnected this thinking i will get the proper plug off cut loom. 6 mths down the line now and i still havnt sorted it but the temperature has never climbed at all not even in summer its sits exactly at the thicker white mark after 70 i think it may be 90 but its exactly half way.

[Rpmayne 0]

I thought the idea of the aux water pump was to keep the coolant circulating after the engine has been turned off to reduce localised heat soak etc which could warp things if very hot. Don't think it's intended to 'boost' the operation of the main water pump. Don't get how the pump working increased the engine temp though.

[OK VR6 0]

Ive noticed that my temp is very close to being on 100 when in traffic, is there anything that can be done to reduce the temp?

[Dub Style 0]

Right following this thread i found this pic on the forum, me thinking i now i know which wire goes where and all i need is a plug, i just checked the colours of the wires on my car and one is brown and the other is red/black.... :( :mad: ........can somone please tell me whats goin on, my cars an L plate

 

 

Edit wrong pic

[Kevin Bacon 5]

The aux pump should run permanently when the engine is running, it's also there to cool the engine after it's stopped as RPMayne says.

 

The main and aux pumps work in unison to cool the engine, so both need to be working to maintain the proper operating temperature.

 

OK VR6, 100 is fine. People sometimes forget that water in a sealed environment has a much higher boiling point than 100 degrees. 100 degs is barely over the half way mark on the guage and is't really nothing to worry about. So long as the rad fans work, everything is under control.

 

If temps in traffic concern you, wire up a switch on the dash to manually over-ride the 3rd speed, which will reduce the water from 100 to 80 degs in 30 seconds :-)

[Dutch24V 0]

Err, Kev, 100 is fine? Mine normally sits at 70 and NEVER goes above 90, ever, even if stuck in traffic for an hour in the middle of summer. I wouldn't be happy if mine sat at 100 put it that way.

 

Also, after talking to Chris (RW1) I'm sure the aux. water pump should not run just by switching the ignition on/off as you say.

 

/Quote

My 1995 Corrado “does not”/”never has” run the aux. pump unless either the ignition is on, engine running or not or….. when the ignition is turned off AND the engine is hot, ie. the yellow sensor has tripped on. In the latter condition it runs, as soon as the ignition is switched off, the rad fan and aux pump until the yellow thermo switch trips off. Turning the ignition on & off does not trip the pump on when the engine is cold.

Quote/

 

The aux. water pump keeps the coolant circulating when the ignition is off, engine is hot AND the fans are on. As I have found out without an aux. pump, the ignition off cooling cycle is very ineficient as the fans are only cooling the water in the radiator, which is kind of pointless and can lead to warping of the head in the worst case as the coolant their is can stay very hot for a long time.

 

Dutch

[Dub Style 0]

Can somone please shine some light on the plug issue i have from what i have read it appears there are two types of aux pump early/late the one in the pic what is that e or l and pleasssseee can somone please check their car. Like i said i have two wires 1 brown and 1 black/red......the pic above shows red and green wires on the plug

[Dutch24V 0]

I've just checked the Bentley and the wires should be Brown & Red/Black, so yours are ok. :)

 

As far as I know there is only one type of aux. water pump accross the VR models, but the new one I got from VW last week is slightly different than the original I took out! The actually motor body is shorted than the orginal and there is a larger plastic sheath around the bottom. The bottom rubber holder will not fit over this plastic sheath. Mine now hangs on just the top holder. Other than that they are the same though.

 

Dutch

[RW1 0]

Beat me to it Dutch, a bit more detail.

 

There are two water pump wiring circuits. Both the same but the fan controller changes and the aux. pump wire colours differ.

 

Early August 1991 to July 1993 (Upto 50PK012000) has a pump with supply wire red/black and earth as brown wire.

 

Later is about August 1993 onwards (chassis 50RK000001 onwards) which has a red/black supply wire and brown/green earth wire. This loom standard has also been made with uprated wiring.

 

Not quite sure where the chassis split is as it differs in different documents but your Corrado has an early type fan controller circuit with 50amp fuse only hence the colour of the wires. See this topic..... http://the-corrado.net/.archive/forum/viewtopic. ... 0&start=30

 

The auxiliary water pump is the same for both circuits although the part number suffix has been updated over time.

 

.

[Dub Style 0]

DutchVR6, RW1, do any of of you have an actual pic of the plug (early type brown black/red wire), i've now determined that the red/black is + and the brown is - but i dont know what is + or - on the pump because all i have is two wires i need to see the plug. The plug can only go on one way so looking at the colour of the wires i'd know + - on the pump

 

thanks for the help dudes.

[dazzyvr6 0]

so should the aux water pump be running when the ignition is turned on,i know on mine it does,as when i took it for an mot the tester was looking at me trying to work out what the noise was

[andy 0]

so should the aux water pump be running when the ignition is turned on,i know on mine it does,as when i took it for an mot the tester was looking at me trying to work out what the noise was

YES! all the time the ignition is on

[Dutch24V 0]

I'm wondering if you maybe you connected your aux. pump the wrong way!?

 

This might explain the higher temps. when running as the flow from the aux. pump would be against the flow of the main water pump.

 

Just an idea. You can buy the connectors from VW still so maybe an idea to get one to prevent it being connected the wrong way in future.

 

Dutch

[dazzyvr6 0]

i disconected my aux water pump for approx 6 months with no problems,i was working under the bonnet with the ignition on and the noise was doing my head in so i dissconnected it and forgot to reconnect after

[Dutch24V 0]

Mine wasn't working for a couple of months too, and normally it's not an issue, but as said in the worst case if the engine is very hot when switched off it could lead to problems.

 

Dutch

[Dub Style 0]

Vw do not list the plug on its own, does any one have any part numbers?????

[RW1 0]

They do!

 

Connector housing - 357 972 752

 

Repair wires with end fittings fitted - 000 979 133 - 2 required. 93p + VAT

 

TBH it's such a common connector, on all VW & AUDIs, it would be worth going down the scrapper and looking. Snip off with wires and just join on.

 

.

[Dub Style 0]

Right bought the plug as per the above numbers and firstly its the wrong one!!, the plug i was given has two little locater type notches cut out the one off the car is supposed to have one.

 

With a bit of moddin with a dremel i sorted that but heres the real problem, connected it all up and turn on the ignition and nothing no sound at all!!, checked with my 12v tester and the ignition on there is no current in the red/black wire, took the car for a run and back and checked the wire again with the ignition off still no current.......

[RW1 0]

Is the plug actually stamped with that part number I wrote above?? (Surprised it's not the correct one)

 

Red/black wire goes to the fan controller. Is the 5 amp fuse in the controller clear capped set of three OK? This is the fuse for the aux pump red/black wire.

[Niges16V 0]

I read this thread with interest as I also found out that my aux wp was dead. I didn't think I had a problem with the temps as it sat at around 80-90° with the odd 110° when sat in traffic in the summer.

 

Fitted a new pump and the temp has dropped by a good 25% so now sits just above 70° and best of all, in these cold dark winter days, the heater starts blowing warm air within a mile of driving!

 

A worthy fix, even though a bit pricey.

[DanA 0]

I've just checked the Bentley and the wires should be Brown & Red/Black, so yours are ok. :)

 

As far as I know there is only one type of aux. water pump accross the VR models, but the new one I got from VW last week is slightly different than the original I took out! The actually motor body is shorted than the orginal and there is a larger plastic sheath around the bottom. The bottom rubber holder will not fit over this plastic sheath. Mine now hangs on just the top holder. Other than that they are the same though.

 

Dutch

 

Just about to fit a new pump to mine, the old one started leaking quite a bit. Managed to get a new (Bosch one) from Eurocar parts, its the same size too. Was around £70.