530i overheated..pissed out coolant.

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canada karl
Posts: 1065
Joined: Tue Jan 06, 2009 3:50 pm

530i overheated..pissed out coolant.

Post by canada karl »

I refilled the cooling system. I had drained it completly last fall. I forgot to bleed the system and went for a drive. The engine overheated and dumped the coolant out the resevoir tube.(all other hoses OK.)
I refilled the system and it didn't overheat again but I had the heater and auxillary fan on.
Would there be be that much air in the system that not bleeding would cause the overheating? I'm thinking maybe the thermostat has quit? The bottom rad hose did not seem very hot! I'l pull the thermostat and check it on the stove to see if its functioning.
I'd like to use the Mahle thermostat but I'd like to get the car back on the road ASAP without having to wait for one to be shipped from Maximillian. Is there cross reference for a generic common 80C thermostat that I can get from say Napa that will fit?
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Post by T.Hanson »

There is the radiator, water pump, hoses, heater hoses, 41 years old, or less depending upon maintenance variables. Perhaps you have read, heard a good way to transform an engine into a glob of scrap metal is to peg the temp gauge for a minute or two. If not a total glob, a very good oil fogger.
There is a procedure for cleaning the radiator. Usually the years want it removed, a cleaner flush used and the amount of crud viewed as an assessment of condition. After that, inspection of the other components and following the factory procedures for bleeding.
Final test is the temp gauge needle.
canada karl
Posts: 1065
Joined: Tue Jan 06, 2009 3:50 pm

Situation resolved....

Post by canada karl »

Turns out it was just an "air lock" caused by my not bleeding the system.It's all good now. I hadn't driven the car since last summer. Forgot how much fun they are to drive.
I pulled the gauge cluster out to replace the mph speedometer with a kph one and to change out a few burnt dash bulbs. I pulled the steering wheel for access and put red locktite on the steering wheel nut when I put it back. Should have checked if everything was working before reinstalling. Seems that the fuel gauge is giving a false reading and the warning light is on all the time! I have a spare fuel gauge I can swap in but it's a pita to have to pull everything out again. :roll:
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Locktite ?

Post by T.Hanson »

Where does anywhere recommend nut glue ? It's your steering wheel.

Tightening to snug plus a dab or the torque spec, besides the odds of coming loose being zero, you would feel it six months of thread turns before the wheel ever came off in your hands.

Locktite is good for needing way more torque to remove the nut, against the ignition, steering stop pin ? Very goofy.
CBradio
Posts: 283
Joined: Fri Apr 06, 2012 12:03 am
Location: Brooklyn

Post by CBradio »

i had the issue with the coolant bubbling over.....

after going crazy and even changing a head gasket:

It was the radiator cap! Did not hold pressure causing coolant to boil over.
1977 530ia
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