Kenny Bradley

My turbo cooling pump has become increasingly noisy and has drawn my attention to how long and how often it runs. I was under the impression that it was supposed to run for 25sec after the engine was stopped and that was it?

I have noticed that my pump occasionally runs when I driving I notice it when I slow down at junctions and in the car park. It will run for several 25sec periods after I switch of the engine.

Is this normal?
Can anyone confirm the correct logic for the pump?

Please let me know what you think.

Cheers Kenny
1991 944turbo
Shetland

Mike B

It has it's own thermostat so that will open when the coolant reaches the right temperature...It is also supposed to run about 30 seconds after you shut the engine off to cool the turbo down...Mine is so quiet I don't even hear it.

Kenny Bradley

Thanks for the repy Mike.

I was aware of the thermostat and assumed the normal water pump would supply the turbo and the eletric one was only need when the engine was shut down.

I've looked over the rennlist archives and the circuit diagrams but can't find anything definate about the logic.

Cheers Kenny

ftanguay

I've check it myself whit a multimeter, and I found a strange diagram. the sensor wire seem to be connect directly to the timer. The strange thing is this wire is 12V+ and the other side of the contact on the timer is 12V- ??? so it sould be short for few millisecond before the timer operate. The timer is actualy a time delay relay. If you check in the fuse box you should see it (928.615.101.01). There is a drawing on the side. I hope this could help you a bit.

Mine seem toast, I was thinking about changing my timer for a Omron time delay, but it's much more pricy than the original module (50$ US).


PS: directly connect your pum wire +/- to the battery to check if it's really dead. but don't let it connect to long. You sould read about 0.3 AMP when the pump is on.