Just got my car back together and afte running it for a bit the turbo waterpump keeps going on and shutting off and then it goes on again and then shuts off. Its just keeps cycling. Any clues to what it could be. Ive replaced my DME relay. Could it be the temp switch?

Thanks
Brian

 

Check the temp sensor on the turbo water line...

 

How do I check it?

 

Water pump should immediately turn off when you disconnect it I believe... if it keeps running the problem is elsewhere... if it turns off and stays off you need a new sensor...

EDIT..sorry, it should run for 30 seconds give or take after being disconnected...

 

I disconnect it and it keeps running any other ideas of what it could be?

 

IIRC it should run 25-35 seconds once disconnected. Disconnect it and keep the wire from grounding to anything, if the pump shuts off and stays off you have found your problem.

 

Does the pump not stop running with the temp switch disconnected at all..it just keeps on running after the 30 second or so timer?

If so...Turbo cooling relay... pull it, get a replacement $176 from pelican, $191 from 944online, or seek second opinion, I would recommend second opinion before buying a 200 dollar relay (it has built in timer function for running the pump after ignition is turned off...)

 

i just found out that mine runs for like 8 minutes. sometimes less. tried different relays, same thing.

 

Maybe you have a misrouted line causing it to suck hot coolant through the engine... it should be pulling from the radiator, and dumping back into the reservoir...

Or you have the special 8 minute mod?

 

Well my mechanic says the temp switch doesn't look stock. I think it's a mod.

My mechanic just replaced my waterpump, belts, o-ring turbo and a few coolant hoses and also flushed the coolant and pressure tested my radiator. A full cooling system check up, and found no problems.

 

try disconnecting the temp switch and see what happens... They are cheap, relays are expensive...

 

maybe you have an air pocket in the system- the sensor sees a higher temp from the air and runs, then the coolant contacts the sensor, cools it down and it shuts off, then the air comes back to the top, comes back on, pumps the fluid till it cools it down...

 

Yeah that sounds right. that could be happening. what to do ?

 

Well, bleeding the system seems to be the obvious thing to do. Maybe that's even the origin of the phrase "the bleeding obvious"?