talltorontoguy

I'm stuck - I'm frustrated - I need help.

I've outlined the situation below including symptoms and what has been done so far to remedy.

Car: 1993 90s, Automatic

At Idle with fans on:

- car will slowly overheat
- upper rad hose hot
- lower rad hose cool

Run car at 3000 RPM with fans on:

- car cools back to normal and holds
- upper rad hose hot
- lower rad hose hot

Efforts to Fix:

- new waterpump
- new thermostat
- new radiator
- new thermoswitch (although have manually turned on fans)
- system flush (2x)
- bled system a million times (broken bleed screws, using heater core hose method - lower bleed screw stuck)

Thoughts?

- blockage somewhere in the system?
- bad thermostat / thermostat backwards (possible?)
- just not bled properly?

Brdman*

but for some reason everything works at 3000rpm when the WP is spinning faster. Did you mix two different types of coolant?

egp320i

cold lower hose means coolant is not circulating, ie. thermo is stuck

talltorontoguy

I didn't mix two different kinds of coolant. In fact there is brand new Audi coolant in the car following the flush, which included an engine block drain.

Would a bad thermostat open up under pressure?