I know this unit a truck forum but I have and 89 318. When I got it the motor would puke all of the coolant out into the resivour. I replaced the water pump, hoses, and radiator. Drove it 700 miles to Florida. Here lately it has started doing it again except it puts it on the ground. It only does it after you turn it off and it set for about 10 minutes. I have replaced the radiator cap several times. Blew air through the resivour hose in both directions. I’m no master mechanic but I do work on all my own vehicles and I’m a fairly proficient mechanic. The motor is bone stock. The smog u it is not hooked up but I don’t think it is part of the problem. I’m gonna do a compression test today or tomar. It doesn’t run hot but it does seem to have excessive pressure in the cooling system. Cracked head? Blown head gasket? It runs really smooth and there is no water in the oil. Or vice versa. Any thoughts would be appreciated. Yes it is a throttle body.
