adding frequently radiator fluid

[jalatorre57]

I see no leaks on the floor after the car is parked in the garage and I'm frequently adding radiator fluid.
what's the diagnoses from the experts?
1988 M5 - with 190K miles

[Bimmerguy2002]

2011
radiator fluid

I seriously hope you guys dont do this....


Check your engine for a milkshake, could be leaking out while its driving.

[Frybrid 524td]

head gasket

[Rich Euro M5]

I see no leaks on the floor after the car is parked in the garage and I'm frequently adding radiator fluid.
what's the diagnoses from the experts?
1988 M5 - with 190K miles

Just because you don't see coolant leaking onto the floor doesn't mean you don't have a leak somewhere.

First thing to check is the radiator cap, they can go soft and allow coolant to boil off only when the car is being driven. I'd replace the cap just to eliminate it. You should also check all the hose clamps on the various coolant hoses for leaks as well. Pay close attention to the hose which runs under the throttle bodies. There is a plastic tee fitting which can develop a hairline crack and leak. Also check the connection on the under side of the coolant reservoir.

[andy535iyes]

I was losing radiator fluid this spring and I couldn't find a leak or drip anywhere for about a month. I though it had something to maybe do with the flush I did earlier in the spring and an air bubble in the system. Anyway, I started to notice some dried white spots back on the firewall on the driver's side. After cleaning, driving and checking I found the source - the heater valve. I thought that maybe the heat cracked the plastic, but noticed that it was missing a washer inside allowing fluid to leak out the small holes. It also only leaked when I ran it hard. Not sure why it started leaking after 2+ years.

Good luck!

[Philo]

Mine eats water as well. I think the issue with these older cars and aluminum thermo housing, header pipe, water pump, is the end that attaches the hoses gets all pitted and just wont seal completely. A small amount of water seeps out as pressure builds and over time the coolant light comes on.

i own three thermostat housing and they all have really bad pitting on the hose ends. I took a dremel to one of them to smooth out the hose race and it seems to help... but the coolant light still comes on every 6 weeks or so.

Over time you'll be able to see the blue/white coolant crusties building up around the hoses where it leaks.

[pat46]

I just solved this problem in a 1985 535i with the same symptoms you are having. I kept adding antifreeze but no leaks-I thought it must be a head gasket (leaking into the cylinder and burning up). I decided to wiggle my fan pulley and sure enough the bearings were going out in my water pump - it was leaking while running and blowing away as I was driving. Had to also replace the lower alternator rubber bushing. Broke lower water pump bolt in the process, but PB Blaster saved the day. Good luck - this was an easy fix compared to a head gasket.

[Philo]

Yup.., just after I posted last my water pump failed due to the fan not being balanced. Some of the blades had pieces missing from the tips. So the unbalanced fan took out the pump.., which allowed the fan to move around and then take out the radiator.., and then the fan disintegrated. Now I have my new group buy aluminum radiator in the car, new water pump, fan belt.. and all is well. No water leaks