horn not working????

Try flushing your cooling system to make the car run cooler.

The horn is located just behind the front grill. It is easy enough to unplug it and hook it up to the battery to test.

I found in my Saabs I can lower the engine temperature by running the AC. The aux. fans kick in when the AC in on. In the Classic 900s you would switch thermostats - one set for summer and one set for winter.

Some not so highly recommended methods for dissipating heat:

1. Run the heater - the heater core becomes a second radiator
2. Buy a windshield fluid pump/tank and use it to spray water over the radiator. Ever notice how much efficient the AC is in a rain storm???
3. Modify the hood with an opening like a hood scoop and use an electric fan to get the heat out of the engine compartment, but keep water etc out

If the cooling system is functioning properly, coolant won't circulate to the heater core when the engine is overheating.

John

How so, John?

You probably meant "isn't functioning properly". But even that is not true I don't think. The water pump discharges to two outlets, (three outlets if you have turbo) the main one to the radiator, a second tubing feeds the heater core inside the cabin to supply heat. Let's say your thermostat is blocked, I think the heater circuit still flows because coolant returning from the heater core goes to the block to the suction side of the pump forming a circuit.

Dave,

I don't have my Bentley manual at hand, but as I recall, flow to the heater core is stopped at high temps in order to divert all coolant to the radiator, which is a far better heat exchanger.

I think Grunff will back me up on this...

John

Hm, that's surprising and counterintuitive. Seems to me, that any heat transfer when you're getting overheated is better than no heat tranfer.

The way I _thought_ it worked, was first the coolant is just engine and heater core, then when it gets above opening temperature, goes to engine, heater core, and radiator.

Dave

What mechanism stops the flow of coolant to the heater core at high tempearture?

The heater core coolant circuit is complely unblocked by any device, at least on a 9000 it is so. Coolant in that circuit is pumped as long as engine is running.

I don't think there is a device to block that flow in _any_ situtation.

Right. The engine/heater core get the heat first, so the passenger gets heat before excess heat is dumped into the radiator.

Since Brother Grunff has not entangled himself in this thread yet, I'm going to go ahead and entangle him:

John

"When the engine is really hot, all coolant is pushed through the radiator, to achieve the greatest temperature drop."

The statement is wrong and inconsistent with both the heater core coolant circuit and the turbocharger coolant circuit, on a turbo equipped unit, both being unrestricted and unimpeded in coolant flow. Of course majority of flow is being pushed through the radiator by virtue of the relative size of discharge pipes on the pump outlet.