318ti overheat and Radiator leak

[mymelody807]

I have a 1995 318TI automatic, the car start overheat few weeks ago and the radiator leak. I order a new Behr radiator and replace it by myself.

I followed the instruction (http://www.318ti.org/forum/showthread.php?t=18066) to change the radiator and coolant. I only change the radiator, upper hose, lower hose and fill it with new coolant. I also followed the procedure for bleeding air out of it, I fill the expansion tank until fluid begins coming out of the bleed screw and at the same time the expansion tank with almost full of coolant (Isn't it suppose to fill it to the COLD mark?).

After I put the bleed screw and cap back, then I start the car and run it for awhile, the upper hose started warm to hot but the lower hose still cold and I squeeze the hose but I don't feel it full of coolant, is it normal? Then the coolant started leak from the bottom of the expansion tank that attached to the side of the radiator. I want to know if it is possible my car cause the leak or the new radiator defective.

[cooljess76]

There's more to bleeding the cooling system than just filling the expansion tank with the bleed screw off. Was the car running when you did it? Did you have the heater on full blast? Was the car parked on an incline with the nose angled up? Yes you're supposed to fill the expansion tank to the top when bleeding the system, it'll level off at the cold mark after you drive it. It usually takes several attempts to get all of the air out of the system. This requires you to repeat the bleed process, letting the engine reach operating temp then cool off several times.

[cooljess76]

Does coolant still leak from the bottom of the expansion tank? It's possible that the drain plug may not be tight or perhaps coolant spilled down the side of the radiator when you were filling it. If it continues to leak, it's possible you may have received a defective radiator, but behr usually makes good stuff.

[mymelody807]

Originally Posted by cooljess76

There's more to bleeding the cooling system than just filling the expansion tank with the bleed screw off. Was the car running when you did it? Did you have the heater on full blast? Was the car parked on an incline with the nose angled up? Yes you're supposed to fill the expansion tank to the top when bleeding the system, it'll level off at the cold mark after you drive it. It usually takes several attempts to get all of the air out of the system. This requires you to repeat the bleed process, letting the engine reach operating temp then cool off several times.

The car was not running when I bleed air out but I have the heater on full blast. The car was not parked on an incline with the nose angled up. What I am concern about it if it is possible the pressure in the radiator or expansion tank cause the leak from the bottom of the brand new expansion tank.
Also how I can find out if the fan is work fine? And the lower hose is cold when the upper hose is warm to hot, is it normal? Or is it mean the coolant didn't go through the engine? Thanks for your reply.

[cooljess76]

Originally Posted by mymelody807

The car was not running when I bleed air out but I have the heater on full blast. The car was not parked on an incline with the nose angled up. What I am concern about it if it is possible the pressure in the radiator or expansion tank cause the leak from the bottom of the brand new expansion tank.
Also how I can find out if the fan is work fine? And the lower hose is cold when the upper hose is warm to hot, is it normal? Or is it mean the coolant didn't go through the engine? Thanks for your reply.

If the car was not running, then the water pump was not spinning. Therefore there was nothing pushing coolant through the engine, heater core or radiator. Bleed it PROPERLY. Follow these steps:
http://www.318ti.org/forum/showthread.php?t=27983

[mymelody807]

Originally Posted by cooljess76

If the car was not running, then the water pump was not spinning. Therefore there was nothing pushing coolant through the engine, heater core or radiator. Bleed it PROPERLY. Follow these steps:
http://www.318ti.org/forum/showthread.php?t=27983

I have tried to bleed it many time, looks like the engine still overheat and blow out all the coolant from everywhere it can such as the gasket ring of the expansion tank and the radiator cap. I think it is too much pressure inside the radiator once it overheat. Also even the engine overheat but the lower radiator hose still cold, is it possible the water pump problem? And how can I test if the radiator fan is work?

[keoniti]

you may have a stuck thermostat -
had that happen to mine - started with fluctuating temp readings - then thermostat got stuck and engine overheated.

Didn't get in the red zone and changed it out the next day - runs fine

[bullmand]

If I'm reading your posts correctly and you're saying that when the car is running it's causing the coolant to leak out of the expansion tank in multiple places you may have warped the head and you're now blowing compression past the head gasket and into the water jacket of the head/block. How badly did it overheat originally?

[mymelody807]

Originally Posted by bullmand

If I'm reading your posts correctly and you're saying that when the car is running it's causing the coolant to leak out of the expansion tank in multiple places you may have warped the head and you're now blowing compression past the head gasket and into the water jacket of the head/block. How badly did it overheat originally?

It wan't that bad when it first overheat, but it got worse day after day. After I found out it leak, the temperature go to RED and steam came out from the radiator, I decided to change the radiator. After replaced with the new radiator and the engine run to normal temperature, the coolant start leak out from the expansion tank and overheat again. I thought maybe defective radiator so I exchange another one, same thing happened. Also I found out the radiator fan not running but I don't know how to make it run all the time. It looks like the coolant getting hot and expand, it cause a crack in the old radiator and leak. With the new radiator, there is no crack and the coolant just blow out from gasket ring and the radiator cap. I don't know it is because the temperature sensor problem so the fan won't kick in or the water pump fail so the coolant won't circulate or maybe like another said thermostat stuck. I have no idea.

[anthony318ti]

Originally Posted by mymelody807

It wan't that bad when it first overheat, but it got worse day after day. After I found out it leak, the temperature go to RED and steam came out from the radiator, I decided to change the radiator. After replaced with the new radiator and the engine run to normal temperature, the coolant start leak out from the expansion tank and overheat again. I thought maybe defective radiator so I exchange another one, same thing happened. Also I found out the radiator fan not running but I don't know how to make it run all the time. It looks like the coolant getting hot and expand, it cause a crack in the old radiator and leak. With the new radiator, there is no crack and the coolant just blow out from gasket ring and the radiator cap. I don't know it is because the temperature sensor problem so the fan won't kick in or the water pump fail so the coolant won't circulate or maybe like another said thermostat stuck. I have no idea.

Is the coolant coming out of the exhaust?

[sunbrn]

You need to take it to a mechanic or have a friend that can help look at it.

[mymelody807]

Originally Posted by anthony318ti

Is the coolant coming out of the exhaust?

I don't see any coolant come out from the exhaust

[anthony318ti]

Originally Posted by mymelody807

I don't see any coolant come out from the exhaust

Oh well at-least we know you don't have a major problem with the head! I guess you should seek assistance as stated above.

[Junk]

replace thermostat and check waterpump, then bleed again (properly). I have seen rusted away water pump blades, completely gone. Lower hose isn't getting warm, water is not circulating.

[AyseOne]

i have the exact same problem as you did with the overheating, leaking from the expansion tank, cold lower hose, fan not working anymore, etc.
everything exactly the same.
i replaced the thermostat, am considering replacing the radiator. want to change the water pump but cant get it out of the block, seized, seems to work though.
did you ever figure out what was wrong and fix it? i would love to know what you learned.
thanks.