Overheating Woes

[julielewis]

My 1989 520i Bmw is overheating still. The thermostat, radiator, fans, water pump and fan clutch are all working fine. When I start the car, the temperatuture needle moves past the 12:00 mark and heads for the red.I first noticed the overheating when I was driving in traffic. I stopped the car as soon as I noticed that the guage was close to the red zone. Help!!!!!!!

[Bill R.]

m50 motor available in 89 in the 520, I would venture to guess that you have a plastic impeller water pump on your 89 520 and that the impeller is broken or slipping, it will look fine from the outside and will spin fine from the outside but the pump won't move much water and the car will overheat. Remove your water pump and inspect it.

My 1989 520i Bmw is overheating still. The thermostat, radiator, fans, water pump and fan clutch are all working fine. When I start the car, the temperatuture needle moves past the 12:00 mark and heads for the red.I first noticed the overheating when I was driving in traffic. I stopped the car as soon as I noticed that the guage was close to the red zone. Help!!!!!!!

[julielewis]

m50 motor available in 89 in the 520, I would venture to guess that you have a plastic impeller water pump on your 89 520 and that the impeller is broken or slipping, it will look fine from the outside and will spin fine from the outside but the pump won't move much water and the car will overheat. Remove your water pump and inspect it.

Bill, the water pump has a metal impeller and it seems fine. What do you suggest?

[Bill R.]

cracked head or head gasket seems most likely.

Bill, the water pump has a metal impeller and it seems fine. What do you suggest?

[632 Regal]

Has it been properly bled? Are the hoses rock hard when it's running? (indication of bad head gasket/crackhead)

[Bill R.]

29.4 pound pressure relief on the cap, so if it warms up the hoses are going to be rock hard whether its got a blown head gasket or not at 29 psi, especially when your used to a 13 or 14 pound system on an american or japanese car.

Has it been properly bled? Are the hoses rock hard when it's running? (indication of bad head gasket/crackhead)

[julielewis]

Has it been properly bled? Are the hoses rock hard when it's running? (indication of bad head gasket/crackhead)

It has been bled over and over. The top radiator hose is hot and the bottom radiator hose is cold.

[Dan in NZ]

Sounds like you're having flow problems... When you say the radiator is fine, what do you mean? Have you had it flow tested to make sure it's not blocked?

Is your coolant expansion tank attached to the radiator, or seperate next to the firewall? If it's near the firewall, the line between radiator and tank can clog causing overheating.

[uscharalph]

Sounds like you're having flow problems... When you say the radiator is fine, what do you mean? Have you had it flow tested to make sure it's not blocked?

Is your coolant expansion tank attached to the radiator, or seperate next to the firewall? If it's near the firewall, the line between radiator and tank can clog causing overheating.

If it's the original radiator, it might be time to replace it. I was having cooling problems and decided to overhaul the cooling system. New radiator, water pump, thermostat, hoses and belts. It was under $400 in parts and we did it ourselves. No more cooling problems.

[grave77]

heating up that fast might be a cloged radiator, but this engine cracks the head faster than you would expect, especially if you tried to cool it down by adding water while still hot. check the coolent for any chocolate colore fluid also notice the hoses if they are expanding like a snake then for sure the head is blown or the head gasket.