After run pump - when should it be on?

Westy

Registered User
[Dave B];1972082 said:
So, I'm curious about the after run pump on the S3. I can hear it come on when I turn the ignition, but it doesn't always come on after I've been out in the car. Does it only come on if the cars in a given temperature range or something, or do I have a problem?

Mines the same. Sometimes if I just turn the ignition on but not the engine it'll run. Other times I can start the car on te drive to put it in the garage and the pump won't come on!
 

Vex182

1x S3 and 3x Fiestas.
Agreed, mine is nearly always on when the car has run and sometimes even when the engine has not been turned over, runs for around 10 minutes or so.
 

jojo

Looking for Boost!
Staff member
Moderator
It should run 5-10 minutes(never timed it) every time the engine is switched off by the keys in the ignition.
 

Sam_

Down under
It seems hit and miss for me, even with a known good pump. Some days it runs, others not.

Is it loud? Mine was loud pre-clean. It's easy enough to take it off and clean it out. 4 screws to remove the "turbine" section and then they'll be bits stuck to the magnets which are behind the plastic housing. Hard to explain but you'll see once you have it apart. Cleaned mine up and it's whisper quiet but runs intermittently.

I have another brand spankers replacement to go on tomorrow. I got this one: Mopar Electric Auxiliary Water Pump 2007 2009 SRT4 Dodge Caliber 05047003AB | eBay (best offer $50 accepted) It's Bosch and brand new. Marginal difference in the hose tail sizes (19mm vs 20mm VW) but for the price difference, can't complain. I'll fit it tomorrow and let you know if it changes anything.
 
Y

Yohan87

Guest
On my Bora 4motion even if you turned the ignition on but not the engine, then turned it off again the pump would run.
 

vrbob

Thats no Moon, Thats a space station!
Yup mine goes for 10mins or so everytime you turn on the ignition (engine does not need to start)

Quick warning to anyone wanting to service their pump, my original one was leaking so bought a cheapo second hand one off ebay for £20. It was defo in better condition than mine so put it on and its ok so decided to try and clean up my old one as a "backup" The 4 screws are a pain in the bum to remove as they become one with the plastic casing through corrosion and the heads snap off very easily!
I managed to hack my old one apart with a hacksaw in the end and now have some bolts holding it together if I need to use it again.
 

Scullies

Registered User
I would remove the connecter plug and test it for voltage while the ignition is on and when its turned off. Would also do this test a few times to see if it an intermittent problem with the wiring. If all is OK then remove and check the pump or supply voltage direct to the pump terminals. Be warned though the inlet and outlet are probably brittle and might break off while you try to remove the hose.
 

Westy

Registered User
One of the 3 green fuses on top of the battery is for the pump and these can also have mucky connectors. Mine stopes working completely once and it wa down to a poor connection at the fuse.
 

superkarl

MAN OF STEEL
Perhaps theyre a bit more complex than 'they should run after every running of the engine. Maybe it depends on other things and sensors etc, no one seems to know exactly
 

Sam_

Down under
I agree Karl, I don't think it always has to run. It might be temperature based. It'd be good if there was some solid evidence either way really.
 

Westy

Registered User
I was swapping my brake light switch yesterday on a stone cold car an I was cycling the ignition. Pump was comming on so it's definitely not temp related!
 

Dani_B19

Audi-sports own special child.
The after run pump should run whenever the keys have been in the ignition and primed, even if you dont fire the engine the pump will run, I bought a brand new pump and prior to that it would be intermittent like some of you guys are getting.
 
It'd be good to get a definitive answer on this, although I don't know quite how we'd do that. I've had a look in the owners manual but there's nothing in there (as you'd expect I suppose). I haven't been out in mine since so have nothing to report. It definitely comes on and stays on when the ignition has been turned on and off though.
 

Sam_

Down under
Fitted my new $50 Bosch after run pump for a Dodge Caliber SRT4:

IMG_4051.jpg


The downside is it has 19mm tails rather than 20mm but the hoses clamped up fine and haven't leaked. Seemingly it's been on after every drive now so maybe the old one was infact knackered? The one that was on there (the one I made out of two good pumps) did run when I moved the car out of the garage to fit the new one but who knows. I'll check when I get into work tomorrow morning and see if it runs.

A bargain if anyone needs one:
Mopar Electric Auxiliary Water Pump 2007 2009 SRT4 Dodge Caliber 05047003AB | eBay
 

Scullies

Registered User
If it doesnt run, how is the turbo going to get coolant to cool it? Now go have a beer and think about your answers :)

I used a pump from a A4, it turned out the flow was the opposite way round. So if you get an aftermarket pump or retrofit a pump, make sure you check the flow direction. You dont want the pump not suppling coolant to the turbo.
 

Sam_

Down under
By driving at a leisurely pace before shutting off I guess. I try not to thrash it to death and then just stop and turn off. Always a good few minutes of granny driving. The pump would also render a turbo timer pretty useless wouldn't it?

That Dodge one is the same flow wise as OEM. Just way cheaper like the Vauxhall ones in the UK.
 

vrbob

Thats no Moon, Thats a space station!
The dodge pump linked above is a bit costly to us UK peeps due to the cost of postage p0lus any import tax they whack on.

So just found this BOSCH additional electric water pump for engine cooling/car heating/ 0392020034 | eBay on Ebay and looks like the same thing for £55 delivered (basically half price of a Audi one) plus it has 20mm outlets like the OEM one so could be a good alternative.

Also I spotted in another thread regarding these pumps that they think the CTS has something to do with the pump running on the car but I cant confirm or deny this
 
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Sam_

Down under
That looks ideal! The 19mm tails thing seems like a minor issue anyway but better to stick with 20mm. The other thing that can be different is the connector. It varies what type they have but the one you linked looks spot on.
 

vrbob

Thats no Moon, Thats a space station!
Yup comes from Latvia and takes a few weeks to get to the UK but for the price it looks good so as my second hand one is working (all be it a tad noisy) I think I will take a punt and get one as have the bracket off my old pump to use so should be good to go :)
 
Great find, it'll be interesting to see what difference it makes, if it's significantly quieter let me know as I might invest in one for that reason and to have more confidence in it.

I was out in mine yesterday and had a listen at a few different times to see if it was on. After a very short run using hardly any boost I stopped the car and it wasn't on, after a long run with plenty of poke it was on, both when the engine was running and when the engine was turned off......the system is either intermittent by design, or the pump is on its way out because of age or there's some other electrical gremlin at work.
 

Tooks

Registered User
The pump should run after removing the key from the ignition, even if the engine hasn't run, but assuming ignition was turned on.

Mine used to stop working intermittently too. If I tapped the pump with a hammer, it would often start which pointed to it being a dodgy pump.

I picked up up a new pump from TPS last week, fitted it and now it runs every time the key is removed.
 

Sam_

Down under
Yep, can confirm as above. Mine seemingly runs after every drive or ignition on/off. It's way quieter too.
 

Scullies

Registered User
A bit off topic, OK OK completely off topic :)

The pump would also render a turbo timer pretty useless wouldn't it?

for me the turbo timer just allows everything to "cool" down while the engine idles for a few minutes. Had a look at the EGT last night, normal driving around town the EGT was just above 600c. So if I turned the car off, the turbo, exhaust mani, and head would be fairly warm. After the turbo timer ran for 3 minutes the EGT was down to 385c when the engine turned off. Will try 4 minutes to see if it can cool down anymore.
Just trying to save my turbo for as long as possible, plus it make me look so Gay-DM :)
 

Sam_

Down under
It is kinda on topic since the after run pump is an OEM equivalent to a turbo timer to cool every thing down after the engine has been shut off. Turbo Timers aren't legal here anyway. Well, leaving your car running unattended isn't and you'd look a bit of a dork waiting for the car to shut off standing next to it. It's probably a little different there in Dubai but I'm pretty sure I don't see 600c poodling around town and the UK barely gets above 25c so no problems there ;)
 

jojo

Looking for Boost!
Staff member
Moderator
Most effective way of preserving your turbo is to coast home/drive off boost the last mile, than rely on a turbo timer/coolant pump!
 

vrbob

Thats no Moon, Thats a space station!
Well just had a message saying my Latvian pump is on its way :)
 

jojo

Looking for Boost!
Staff member
Moderator
Is there a trick to doing this? I find it very hard to cruise anywhere. The motorway is about the only place I cruise as there are cameras everywhere.
As soon as I get off the motorway its.....

View attachment 21282

Just drive normal, not fast for the last mile home, how hard can that be? Surely you warm your car up before you cane it, you just cool your car down with a bit of short shifting driving. No accelerate = no boost = no heat generated on turbo.
 

vrbob

Thats no Moon, Thats a space station!
*Update*

Righto, Had a bad back the last few weeks so not been doing much on the car at all but my Latvian Bosch generic after run pump had arrived earlier this week so I was keen to fit it.

The pump itself is identical to the OEM pump it just does not come with the little bracket/holder that goes around the motor and attaches it to the car.

So as I know its a quick job and am not in too much pain at the mo I gave it ago this afternoon. Took about 20mins to swap over (car was almost cold) and quick check with ignition off and then on again (no engine start) pumps runs lovely and quiet.

So all in all for £55 delivered compared to the Audi OEM price its defo worth doing if your pump is noisy, intermittent, leaking or broken

Link to the pump on ebay BOSCH additional electric water pump for engine cooling/car heating/ 0392020034 | eBay
 
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Searider

Registered User
Evening all,

where does the after run pump live? I've never been aware of mine running and it's always ****** hot under the bonnet in comparison with the S4 and RS4 I've owned.

As an aside, on the S4 and RS4 the auxiliary coolant pump only comes on when the ignition has been turned off and the coolant is above a certain temperature. A common mod is to change its sensor for a lower temperature one. The coolant flow is in the opposite direction to the normal coolant flow.

Is there an S3 self study guide from Audi, for their technicians, as there is for the 2.7twin turbo engine in the S4 and then another for the RS4? Those explain how all of that stuff works.
 

vanilla_ice

Registered User
I know this is an old thread...

I replaced my after run pump with a Bosch pump approximately 5 years ago.

More recently I noticed it had become very intermittent and eventually stopped working. Someone suggested checking the green fuses above the battery. I could see the plastic below the left hand fuse had gotten warm at some point, so the fuse holder was replaced with an original used part without any apparent damage.

Since then the after run pump has begun working again, but it is intermittent when it runs and it's running speed fluctuates. Is fine when powered directly from battery.

I'm convinced there is a link between having the climate control on and the pump not working. As in it seems to run more often when the heating hasn't been used. Not ideal this time of year!

Can anyone shed any light? I also have comms errors when scanning the HVAC with my VAG-COM. Could this be linked somehow?

Thanks.





so hopefully still 'good'.
 

s3mad_dude

Noggies ruuuule!
It's my birthday
My pump was replaced a few years ago and it runs even if I start the car, move it two inches and then turn the engine off. It runs for about five mins or so after turning car off.

Sorry, I can’t help with the pump speed issue though.
 

Nick8l

New Member
Is it possible for a faulty pump to cause the turbo to shut off?
I can drive my car chill for hours and have turbo but as soon as I actually use the turbo properly it usually shuts off within 10 mins or so.
I've got the replacement pump ready so guess I'll find out.
And maybe a dumb q but should you drain coolant a bit before doing this job or not necessary?
 
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