Scott at Team Harco

So the achtung light came on as I was nearing my destination two nights ago. It was for high coolant temperature.

I messed around and put more coolant in and called it a night. The next day - yesterday - we headed out with some extra water in case of a repeat. Didn't get very far - the needle climed to the top of the gauge. Stopped, opened the pressure relief screw and topped off the coolant. Proceded to go through this routine about 6 or 7 times to complete the 10 mile trip to our farm.

I assumed it was a stuck thermostat. Since these are impossible to check or remove when in the vehicle - I ended up breaking the thermostat open so it would flow coolant. This did not correct the problem.

I am now thinking the remanufactured waterpump that I installed, just this past spring, has failed. Based on the speed at which things heat up and get hot - I am thinking that the pump is not pushing water at all. How does this happen? Is it possible the impeller is not spinning on the shaft?

Jfrahm

I had this happen, the impeller can spin on the shaft as you suspect. It is tempting to tack weld or roll pin it but that wrecks the core.

MooreBoost

could it be the belt slipping on the pulley or maybe a bad headgasket? check the tension on the belt by the water pump

J Berk

I had a similar problem coming home from Hershey a few years ago. The PO had put one of those non-OEM cheap waterpumps in the car. It had a plastic impeller and the vanes had actually worn enough that it was no longer moving a sufficient amount of fluid....so if I drove below around 70mph it would be in the red zone.

It was a FAST drive back to NJ and the pump was replaced with the (much more expensive) new OEM unit and has been good since.

GL!

Joe

Scott at Team Harco

Definitely no on the belt slipping. Highly unlikely on the head gasket.

Scott at Team Harco

That seems to be the logical explanation. Sure doesn't seem very logical though.

xsboost90

so where is the water going? overflow tube? Seems like if it was just getting hot that you wouldnt need to keep refilling the coolant....

Scott at Team Harco

Yes - it must be going out the overflow.

944S2IFISH2

I had a similar (Identical?) experience with my '90 S2. The factory original pump failed at IIRC 50 ~ 60K miles. It had a plastic impeller which began to spin on the shaft. I believe that it is press-fit from the factory and that the heat cycling / age cause it to eventually loosen. On mine, the pump vanes looked perfect, the shaft/bearings had no excessive radial or axial play, there wasn't a drop of coolant leaking, but when I got the pump off it was obvious - with the pulley held stopped the impeller spun easily.
Good luck with it!

Scott at Team Harco

I got the pump out yesterday. The impeller was loose on the shaft and it came right off when I grabbed on to it.

Ordered a new (rebuilt) unit. Will need to very careful with regard to belt tensioning with the auto-tensioner. It may have been too tight.

J Berk

Curious why you went the rebuilt route?

When I did mine a few years back, it was only about $100 cheaper than new....and when you add in the labor if it **** the bed.....I sprang for the new one.

Also curious...was the one that failed the non-oem with the plastic impeller?

Scott at Team Harco

Rebuilt is $99. New is $330. That's a lot more than $100 difference. The extra $230 can be spent on other things.

Yes - it had the plastic impeller. I don't know that is was non-OEM. It's very likely that it was an OEM pump. It was not that important to me to fully investigate whether it was or was not.