My 87 924S started overheating. Replaced water pump, thermostat, Pressure tested, replaced head gasket, oil cooler seals, radiator, No smoke from exhaust. No oil in water, no water in oil. Can not detect any more leaks, pressurized cooling system to 16 lbs, replaced radiator cap with 16 pound cap. Coolant never gets warm in reservoir. purged cooling system but I do notice bubbles in turkey baster when system is topped off from bleeder screw on top of cylinder head while engine is running. It will continue to loose water with bleeder screw open. Cleaned all grounds, checked temperature gauge and replaced sending units, radiator fan switch relay and blue sensor on cylinder head, low speed and high speed cooling fans do kick in and continue to run till temperature creeps toward upper portion of scale, 1/2 to 3/4. I have not let it run into the red zone yet. Ready to pull the head again and send the head out. Any more ideas?

 

Bump, he needs help...

 

I have the same problem, and would love to know a solution as well...but nobody can seem to figure it out.

 

make sure the water pump is turning...i only use brand new pumps and factory parts.....make sure your thermostat is opening as well.....

 

While running are both upper and lower hoses similar at temp ? ( feel with Hands check for flow )

Aslo jack up the front of the car and bleed again , ( pinch hose at resivior and blow into coolant tank , this will force the water out of the bleed hole . ( removing air ) Dp951

 

Been there done all that. With the radiator system pressurized cold engine off the cooling system holds 16 lbs, heater on too. With car running and temperature comes up repeatdly bled system. air bubbles still coming from bleeder , continue filling system and air bubbles still present. It appears as if I am getting drops of coolant from the back side of the drivers side of the engine. drip every three or four seconds. It is not the heater control valve, heater core or hoses, heater control valve flange. I do not see any leaks coming from the edge of the head gasket either, It appears to be heat related when the engine comes up to temperature and the head starts getting hot. Both radiator hoses are the same temperature, water pump verified, thermostat, gasket and shims double checked, radiator swapped out, oil cooler resealed. Head gasket replaced. I am wondering if there is a freeze plug on the back of the head or block that is starting to weep or if the head gasket and or head is warped. When I replaced the head gasket I untorqued it in stages working from center to outside edges, same when I reinstalled the head. Did not notice anything obvious with the head when I had it off, cracks, corrosion, etc....

 

is the car really running as hot as you think....just a thought...

 

the blue sensor is for the fuel injection not the guage....

 

Gotta ask it. Did you ever check to make sure your radiator/ condenser fans are spinning the right way? You can always test easy with a sheet of paper, should always suck in from grill to engine, not push hot engine air through rad. Just a thought. Have had simlair problems in past, body shop cars are notorious for messing up grounds and wires after and accident repair, good luck