# VW 1.8 Auxiliary water pump (Beetle)



## Bluestream (Jul 16, 2011)

This engine has an electric water pump to cool down the turbo after the engine is shut off. I s the auxiliary water pump to run every time the engine is shut off, or just after coolant reaches certain temps? I have jumped 12V to the pump and it runs, but I have never heard it run on its own. 

What sensor turns it on, and any way to test it?


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## AmIdYfReAk (Nov 8, 2006)

it will kick in if the motor gets hot enough, and stay on for a little after the car is off. 

The pump is for all 1.8T Automatics listed for warm climate.


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## Bluestream (Jul 16, 2011)

AmIdYfReAk said:


> it will kick in if the motor gets hot enough, and stay on for a little after the car is off.
> 
> The pump is for all 1.8T Automatics listed for warm climate.


 Thanks, I think is in a 5 speed Beetle. What is the sensor, or module that turns it on? I think I should have heard it run at least once, but nothing. Lots on contradictory info in the archives.


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## jeeprnovru (Jun 24, 2011)

im also interested in what cars have this AWP...i have an 04 jetta 1.8T with a manual trans....do i have this? so the K03s is water and oil cooled?


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## AmIdYfReAk (Nov 8, 2006)

If i was able to get into Etka, i would show the screen shot of it stating Automatic warm climate only. 

Beyond that, you are correct, there is a lack of information about it. 

In fact, i can remember a thread a while ago where people said it was the wrong car, or aftermarket. 

Anyway, the only reason i looked into it was because my 1.8T was from a Tiptronic Mk4 that had the pump. 

its still in my basement.


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## carlb79 (Mar 21, 2011)

I just went through this. If the aux pump isn't coming on every time you shut down then replace it. My pump would work when the motor was cool but not when it got hot. I replaced it and now it comes on after _*every*_ shut down.


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## l88m22vette (Mar 2, 2006)

It is because the k-series turbos are oil- and water-cooled, it will come on when you turn off your engine regardless of trans or what not; our turbos are tiny, and as a consequence produce a ton of heat.


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## AmIdYfReAk (Nov 8, 2006)

l88m22vette said:


> It is because the k-series turbos are oil- and water-cooled, it will come on when you turn off your engine regardless of trans or what not; our turbos are tiny, and as a consequence produce a ton of heat.


I could see that, 

Though, why its on the automatics and not the standards is beyond me.


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## l88m22vette (Mar 2, 2006)

l88m22vette said:


> *regardless of trans*


:wave:


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## Bluestream (Jul 16, 2011)

I jumped the pump again and this time nothing. I:banghead: tapped it with a small hammer and it started running. Tried the jumpers again and it runs on an intermittent basis. I taped a bit harder with the hammer and it ran real strong. I guess I am looking at a new pump, or a motor rebuild.

My question, is this pump really needed if other 1.8T models don't even have one?


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## l88m22vette (Mar 2, 2006)

ALL 1.8Ts HAVE THEM :banghead:

They are known to fail or run too long, try replacing the relay first, with VW/Audi electronics almost always fail before the mechanical part does


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## AmIdYfReAk (Nov 8, 2006)

l88m22vette said:


> ALL 1.8Ts HAVE THEM :banghead:
> 
> They are known to fail or run too long, try replacing the relay first, with VW/Audi electronics almost always fail before the mechanical part does


No, they do not. 











Manual Equipped cars did not have it, and not all Automatics had it either...


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## Bluestream (Jul 16, 2011)

l88m22vette said:


> ALL 1.8Ts HAVE THEM :banghead:
> 
> They are known to fail or run too long, try replacing the relay first, with VW/Audi electronics almost always fail before the mechanical part does


Not sure how a bad relay would cause the pump to run when tapped with a hammer???:facepalm:


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## carlb79 (Mar 21, 2011)

Replace the pump.


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## radlynx (Jan 4, 2007)

agree, replace the electric pump.



carlb79 said:


> Replace the pump.


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## Jayj (Jul 1, 2011)

l88m22vette said:


> ALL 1.8Ts HAVE THEM :banghead:
> 
> They are known to fail or run too long, try replacing the relay first, with VW/Audi electronics almost always fail before the mechanical part does



If tapping on the motor causes a change then this statement is obviously wrong. I would also disagree with your opinion that vw/Audi electronics are subpar.


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## Bluestream (Jul 16, 2011)

The pump has been running like a Champ in the week since I taped on it. I check it 3-4 times per day and it is always on for 10 after shut down. Until that changes its staying in


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## groggory (Apr 21, 2003)

l88m22vette said:


> ALL 1.8Ts HAVE THEM :banghead:
> 
> They are known to fail or run too long, try replacing the relay first, with VW/Audi electronics almost always fail before the mechanical part does


Not all 1.8t's have them.

My 2000 AWW GTI 1.8t 5spd didn't have one

My 2002 AWP GTI 1.8t 5spd doesn't have one

My brother's 2003 AWP GTI 1.8t 5spd doesn't have one

...just for instance


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## marcelozaupa (Sep 8, 2008)

*Auxiliary pump*

Not sure about only automatic having the eletric pump, my 01 beetle 1.8 t, auto DOES have the pump. My buddy 00 1.8 t STICK shift, DOES have the pump as well. I personally looked at it and is there.


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## radlynx (Jan 4, 2007)

yes, don't remove it. it's there to avoid hotspot on the engine and turbo and helps it cool the engine down. it runs for 10 minutes after engine shutdown.



Bluestream said:


> I jumped the pump again and this time nothing. I:banghead: tapped it with a small hammer and it started running. Tried the jumpers again and it runs on an intermittent basis. I taped a bit harder with the hammer and it ran real strong. I guess I am looking at a new pump, or a motor rebuild.
> 
> My question, is this pump really needed if other 1.8T models don't even have one?


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## o2bad455 (Aug 22, 2003)

While I agree that not all cars seem to have them, ETKA does show different part number pumps for different applications (above and beyond the above-quoted part for 2003 Jetta with 5-speed automatic trans). For example, a quick check of ETKA indicates that *ALL* 2002 New Beetles sold in USA had "additional water pump" "251 965 561 B" instead of the previously mentioned part. Unfortunately, I can't post a pretty screen shot due to running a virtual machine under Windows 7, but it's definitely there on my '02 Beetle Turbo S (6-speed manual trans). 

My main question is whether it/they have sufficient flow and correct routing so that I can jumper it to cool the engine temporarily with a failed main water pump. I didn't find any posts on that point, but I might just give it a try. If not, I see high flow remote electric water pumps available from several racing distributors with flows from 20GPM to 50GPM (and current draws of just 6-7 amps) that should work until it gets warm enough outdoors for me to tackle the main pump job. I'd just have to pick the right pump or adapters, and figure out the best hose to install it in. I'm thinking in the lower radiator hose would be good after warm-up, but not sure if that would be okay when cold (thermostat closed).


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## reneparedes (Apr 24, 2016)

*Gray or blue smoke at the tailpipe could be a not functioning auxiliary water pump*

Just clean the connector. It will work again. My 04 AWP Tiptronic Jetta 1.8T, it was not working, and that was causing overheat at Turbo, so it start experiencing some sort of dilatation, starting to flush some oil to the exhaust manifold troug the turbo o-rings (I think), getting big clouds of gray-blueish smoke, and the dash was marking a 90° temp at the gauge. Since I was able to find the auxiliary water pump was not starting (anytime), because of a lack of electric contact at the connector, the smoke problem stopped. I tihink it was due to a dilatation of the turbo, that was not recirculating coolant. 

If cleaning the connector terminals is not starting the auxiliay water pump when the car is turned off, try wacking it softly with a hammer and a screwdriver, hitting the metal on it. Sometimes, the electrical contacts made some kind of carbon (the pump is operated with a brushless, so it uses carbons). When the carbons are starting to die, the carbon debris were covering the whole metal parts inside the pump generating a lack of contact, so, wacking the metal assembly will undo that carbon deposits at the terminals, and there will be contact again.

As a plus: Follow the line that goes to the auxiliary water pump, and attach a LED at the red "L" connector (just above the passenger headlamp), so you run a line that ends on the dash, just to know if it is working or not while I'm driving. I have a pair installed (one for the auxiliary water pump, as I stated before, and another one just to know when the radiator fans are working).

Hope this helps.


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