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Additional cooling pump

Chumeta

Passed Driver's Ed
Location
Vitoria-España
Can the operation of the additional cooling pump be regulated in any way? In particular, that it always starts when the engine is stopped in order to cool the turbo. I think it would be advisable in all reprograming, since the boost in all stages is higher than oem and much more heat is generated. Base its implementation? Excuse me for my english. Thank you
 

GTI's

Drag Race Newbie
Location
MD
When coolant pump V50 does run after engine is shutoff it flows coolant in the opposite directions of normal flow of coolant when engine is running.
 

GTI's

Drag Race Newbie
Location
MD
I have not seen a lot of info on the auxiliary coolant pump V50 except for what is in SSP 821503



and from erWin

Coolant pump - V50-
❑ The direction of coolant flow in after-run operation is opposite the illustrated direction of flow
❑ The functions can be checked with Output Diagnostic Test Mode (DTM) ⇒ Vehicle diagnostic tester

I can tell you that the pump will turn on anytime the engine is turned off even if the engine is cold. It pump gets its power from a the auxiliary pump relay that is commanded on by the ECM.
 

GTI's

Drag Race Newbie
Location
MD
That is what it says but I have seen in Vcds looking at ECM measuring block 136-3 that the pump is off when engine is running but if you turn a cold engine off that field will show on for a second or so before Vcds loses com with ECM. Was not sure if what I was see was correct so I removed the plug from the coolant pump and installed an led test light and the same thing happened with the test light came on for a sec or two on a cold engine.
 

vwengineer

Ready to race!
Location
Switzerland
Oh ok, just briefly then? Could it be that some kind of control module responsible for the operation of this pump switches on when the engine is shut off and that it turns it off directly due to the engine being cold?
 

GTI's

Drag Race Newbie
Location
MD
Seeing that the ECM controls the relay for the coolant pump it must be the ecm that is in control. How the ecm goes about and for how long to run the coolant pump I have no idea. What I can tell you is that if you get the engine up to temp(190°) at a standstill and turn the engine off the pump will only run for a second or two.
 

Chumeta

Passed Driver's Ed
Location
Vitoria-España
Well, it only works for me when stopping sometimes, always when the day is hot and the car is very hot, if not, it doesn't work for me. Anyway, nobody seems to know what parameters the EMC relies on to give the signal to the additional cooling pump. Thanks
 

vwengineer

Ready to race!
Location
Switzerland
Seeing that the ECM controls the relay for the coolant pump it must be the ecm that is in control. How the ecm goes about and for how long to run the coolant pump I have no idea. What I can tell you is that if you get the engine up to temp(190°) at a standstill and turn the engine off the pump will only run for a second or two.
Could be oil temp or EGT? Not sure if US spec cars have the oil temperature sensor though since I think it's linked to oil level sensor. I heard mine run for some time after switching the engine off in hot weather. I cannot comment on how often it comes on because I only heard it when parked in a small garage (and I usually park in the street) but definitely not systematically.
 

GTI's

Drag Race Newbie
Location
MD
Well, it only works for me when stopping sometimes, always when the day is hot and the car is very hot, if not, it doesn't work for me. Anyway, nobody seems to know what parameters the EMC relies on to give the signal to the additional cooling pump. Thanks
Are you sure you are hearing the pump and not the after run cooling fans system kicking in. If you perform an autoput test on the coolant pump it is pretty much silent. The fans are like a jet plane.
 

GTI's

Drag Race Newbie
Location
MD
Could be oil temp or EGT? Not sure if US spec cars have the oil temperature sensor though since I think it's linked to oil level sensor. I heard mine run for some time after switching the engine off in hot weather. I cannot comment on how often it comes on because I only heard it when parked in a small garage (and I usually park in the street) but definitely not systematically.
Us spec MK5 do not have oil temp / level sensor so it not using that. I am beginning to think perhaps it tied into the after run system.
 

vwengineer

Ready to race!
Location
Switzerland
Pretty sure it was the pump, it was a very faint noise which I never heard before, only audible because the car was in a small garage.

Can the fans run with the engine off/car closed?
 
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Chumeta

Passed Driver's Ed
Location
Vitoria-España
I have heard it too, inside the garaje. The sound of it is a soft hum when turning off the car on hot days and with a hot engine.
No one can clarify in detail, on what parameter is the EMC based to turn it on and off? thanks
 
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