No coolant flow after new WP install
 

Hi,

'87 S4 Auto Euro

I have just put the front of the engine back together after replacing the water pump, TStat, belts and dist caps/rotors.
I filled the rad through the bottom hose, reconnected the hose and topped up at the coolant reservoir.
It took only 8 litres of coolant.(It was fully drained from the rad plug and 2 plugs under the engine.

With the internal heater blower on full I started the car.
It runs for 10mins then the temp gauge goes into the red.

The internal blower is blowing cool air and the hose connecting to the bottom of the rad is cool.
Could this be air in the WP or a stuck thermostat or something more?
The car is on an approx 2% incline should this effect its ability to self- bleed?

Any ideas on how to move forward?

Many thanks,

Wavey.

Thermostat
 

Did you replace the thermostat also? Sounds like you have air trapped.
You could try to run the engine again keeping the reservoir cap off to see if any air can come out. Or remove the temperature switch and see if you get a consistent flow of antifreeze coming out

Also park the car on the incline so that the reservoir is higher than the radiator

If you squeeze the hoses, do you hear water or get bubbling in the reservoir? I always fill mine from the reservoir tank (maybe 5 or six times now) and have never had any problem. But yes it sounds like there isn't any water in the water bridge thus not heating the thermostat. Could try loosening the temp II sensor and seeing if you get air.

The system takes approx 14 litres of coolant after a TB/WP job as I recall so something seemingly not right. I always fill through the expansion tank and like to remove the radiator vent line until I know it is flooded.

Even so no idea why you have the result you have- I doubt a slight incline should cause any grief.

I have the cap of the expansion tank, fill the system and always "pump" both front radiator hoses with my hands, burps the system well from air. Keep topping up in the expansion tank until it stays at half full. Then start the engine for a short while with the cap off and let the residual air escape. With the cap on, you should then be good to go. If your thermostat and other things are good that is...

I always prepare a sacrifice before vehicle maintenance.

So for, the Gods have been happy.

...can't hurt to try..

https://cimg5.ibsrv.net/gimg/rennlis...b324b1c4bd.png

To get my GT to finally bleed, I jacked the front of the car up, removed the radiator cap, started the car and just let it idle while squeezing the radiator hoses every now and then. It self-bled with no problems afterwards.

Ended up topping up the water bridge through the Temp sender port and running on an off for an hour or so.
Finally got the air out and she is perfect now.

Had a terrible feeling that the newly installed WP impeller was not turning somehow!

Back on the road after a month.

This:

Airlift refill kit

Airlift refill kit

... UView 550000 Airlift suction refill kit. It uses a shop-air venturi pump to suck most of the air out of the cooling system, close a valve and watch for a stable vacuum, then switch hoses to a 5-gal bucket with about 15L (4 gal) mixed coolant and open the valve. It sucks the bucket dry in about 30 seconds, done.

Goats are probably cheaper, however.

I used to dread cooling system work before getting the AirLift tool, especially on my GMC Sierra Pickup where it was a nightmare to release the trapped air. This thing makes it literally a one and done proposition. I've used it on 928s, 997s, a 944, an Audi Q5, and the GMC.

Loosen the top rad hose, swing it up, and fill the system with coolant from there as well as the expansion tank

You will get 15 L total in, and there's no need to bleed anything

I bought that product. Used it once and it was great.

After that It would not hold vacuum. Tried to get it ait tight and in the process broke the brass fitting.

I reached out to them get it looked and they wanted almost as much as paid for it to fix it.