1998 BMW 528 coolant in engine compartment

AIN429

MEMBER
1998 BMW 528
6 CYL
2WD
AUTOMATIC
115,000 MILES

I have been having overheating problems for past few months. Changed the clutch fan and seemed to help but still gets gets hot once every few weeks. Inside the engine compartment there is coolant sprayed and I no idea where it is coming from no obvious leaks. Top hose gets hot but bottom take a while even after car is warmed up.

3 Replies

PEAR69

MECHANIC
1,482 POSTS

Does the bottom hose eventually get as hot as the upper hose?
If the coolant is sprayed all over, then there is an obvious leak somewhere. You could have a pin hole leak in the coolant hoses anywhere or the radiator may have a pin hole leak somewhere. A way to find this leak (without dealing with hot coolant) is to pressureize the coolant system with compressed air. This is done by installing a special radiator cap, with an air hose fitting, on the radiator and applying compressed air to the system.

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Wednesday, September 16th, 2009 AT 10:26 AM

AIN429

MEMBER
2 POSTS

I checked it when my wife got home and it was not as hot. As for the leak it doesnt leak all the time but looks like it might be under pressure when it does leak. Can it be clogged radiator or stuck thermostat causing pressure to build up. I'm trying to avoid changing all this and then find out it is head gasket or warped head. Thank you for replying

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Wednesday, September 16th, 2009 AT 11:26 AM

PEAR69

MECHANIC
1,482 POSTS

The best way to check the condition of the head gasket (without ripping the head off) is to do a leakdown test and a compression test on all cylinders.
The t-stat is probably stuck also -- causing a build up of pressure. This pressure is leaking out somewhere, worst case, it may be a head gasket -- but test to be sure.

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Wednesday, September 16th, 2009 AT 11:31 AM