zogster

I think the water pump for the turbo isn't working on my car, but I'm not quite sure how to check and fix it! (To be clear, I mean the small electric pump that supplies cooling water to the turbocharger)

Situation: testing and shaking down after several weeks of extended replacing stuff and reassembly... clutch, engine mounts, oil pan gasket.

Engine appears to be running fine (have started and run it a few times so far, one short test drive), but each time I've checked the turbo water pump, even with the engine hot, it's not running.

How can I troubleshoot this?

edit: the fuse for the pump hasn't blown

fejjj

Check to see if it is running after you turn the engine off while hot.

cruise98

It should run for about 30 seconds each time you switch off the ignition. It also runs off of a thermoswitch.

Dave951

There are a couple of things you can check.

1) Relay; the pump is controlled by a relay and if this goes bad you can get some unusual behaviors.

2) Thermoswitch; you can measure the resistance here. At room temperature the switch should be open then at 190F (not 100% sure on the temp) it should be closed.

3) Aux Pump; if you can directly attach a 12v power source and ground you can test to see if the pump is indeed working.

michael7810

Also - when the pump is working you should see water moving in the plastic overflow tank

zogster

Groovy - that should give me enough to troubleshoot, thanks.

Unfortunately on my first proper test drive I found hesitation/bogging down under acceleration, and now the engine dies immediately after starting. So I probably need to track down an electrical problem or a vacuum leak.

And *then* I can figure out what's going on with the turbocharger pump

zogster

Looks like it's the pump itself. Which surprised me a little, just because it seems like an odd coincidence that the pump would go when I fix a load of other stuff... but I guess it has to fail some time.