84 bbi dumped coolant...

Could be over full or a bad cap that doesnt hold pressure. Possible the engine is running to hot or it needs a head gasket. So, there are several posibilities. Check the level is correct and you arent running too hot, if it continues have the cap tested and go from there.

 

My car doesnt run over 90C ever and never dumps coolant. If the cap isnt holding pressure it will run hotter and dump coolant during driving and moreso when shut off. You need a pressure tester with a cap adapter, it should hold the rated pressure on the cap itself such as 12psi or 14psi, whatever the cap is rated for that you are using.

 

mine does this also...works fine while running but dumps when the engine is shut down!

i want to see who has the solution here...btw...mine has a brand new rad cap.

 

It could just be overfilled? Once the car cools down how is the level in the overflow tank ?

 

check the level, how hot does yours run? You might have to run the level slightly lower than spec if you need the room for expansion (which is what the tank is for) and since its the higest point in the system running a little less will have no effect on cooling but allow for hotter temps without dumping if you live in a hot climate.

 

My BB512i runs between 85c and 90c most of the year. It will nudge a needle width over 90c in July 95f+ weather if I get caught in stop and go traffic

 

Paul,

she runs at 100 degrees c and I do check it each time I use it. I have often taken off the cap to see if the coolant is rushing through the system and it always appears to be.

How full do you run yours? when cold, how far do you fill up the expansion tank? I may be running too much coolant?

pcb

 

frank, when the car is shut down and cool, the expansion tank looks empty. does yours as well?

 

No, even in the hottest Georgia weather the level is always about 2 inches below the overflow tank neck

 

I run about 25% BMW coolant and 75% distilled water in mine and it will only exceed 90c on a 95f+ summer day in stop and go traffic. Check to see if your fans are running at full speed. A few years back my Boxer started running 95c+ and believe it or not it turned out to be my alternators needed to be rebuilt...while the fans were turning, the alternators weren't putting out enough to turn them a full speed. After the alternators were rebuilt,the fans started turning noticeably faster and the temp went down to 85c to 90c...you could now fly a kite over the front vents in my Boxer the fans push so much air! Stop by a Pep Boys or AutoZone and they will test your alternators for free...

 

Another elusive problem can be coolant to water ratio, too much coolant to water (over 70% coolant) will make a car run hot. I can see the coolant in the tank when hot but its low, cant remember the last time I checked it cold so I cant tell you where its at then. If the car is running 120 C I would want it cooler and verify first that it is actually running the temp the gauge says it is. If its running that hot you have to have it checked and start with the basics because chances are its simple once you find it.

 

If its running 120c, you need to turn it off and flat bed it to the shop...otherwise you will be in for some real expense!

 

100 c is where she runs at. fans are working perfectly.

 

sounds like you need to bleed the cooling system, Boxers are very picky about this my car did the same spilling fluid when parked after a run until I got all the air out

There is a small bleeder valve on top of the radiator mine is in the right side top you crack after the thermostat opens and water circulates, keep bleeding until air is gone, there is also a bleeder on top of the motor but I didn't need to use it, don't forget to open the heater valves as well

 

All 3 fans turn on at the same time on my BBi, one only is not right.

 

All three fans should only be on when the A/C is on. If the A/C is off, only the two black fans should be on...the yellow fan is for the A/C.

 

You have a problem with the fans or wiring. The two black fans should come on once the temp sensor in the radiator reaches a certain temp...about 80c if my memory is correct....(the OM does have that temp listed though so check my figure to be sure). Those two black fans cycle on and off as the fluid in the radiator temp changes due to how hard you're driving the car, outside temp., as the thermostat opens and closes, ect. The yellow fan only comes on when you turn the A/C on. 100c is too hot unless you're really dogging the car on the track in the summer...80c to 90c is the normal everyday temp the car should run...

 

Well then someone modified mine for the better, mine all come on at the same time. Ill look into it but couldnt find anything noticable but more importantly mine never goes north of 90C.

 

It surely won't hurt for all three to come on at the same time I suppose...not necessary as mine only runs 80c to 90c with the two fans, although I do have my A/C on from March to December so all three do run a lot anyway. The correct sequence info is in the OM though.