Cooling problems 92 525 e34

[kzpuck]

Replaced water pump about six months ago, didnt have problems again until about a month ago. Replaced upper hose which was leaking, still had overheating problems. Replaced thermostat, still loosing fluid and overheating.
My mechanic pressure tested, said need new radiator. I replaced radiator, still have to put fluid in everyday. I bled the sysyem every time I replaced anything. Dont know what to do now. Could it be the heater core? any input
would be much appreciated, thanx.

[uscharalph]

Could be the heater core. Maybe a stupid question, but did you replace the radiator cap?

[kzpuck]

New radiator did not come with a cap so I just used the old one, I'll check that out.

[uscharalph]

Radiator caps should be changed after a while, especially after overheating problems.

[Dave M]

HOw much coolant are we talking about here? I'm assuming that since you've been through all these part replacements, and the system has been pressure tested, you haven't identified an external leak. If you're filling the resevoir daily and its headed straight out the heater core, you should be aware.

With the heat on, do you smell coolant (sweet smell)?

Does your windshield fog up or get a thin moist film on it just above the vent?

Is the carpet at the footwells damp/wet?

Is there a chance its leaking onto something hot enough to evaporate it? Its doubtful as the M50 exhaust is nowhere near coolant hoses and it sounds like you're losing quite a bit.

Its not rocket science, coolant doesn't travel any further back than the heater core, so if you don't find signs of an external leak, you might want to start thinking (and I hope you don't have to) about that coolant heading out your tailpipe or into the oil. Check your plugs for crusty white deposits, check the oil for frothy, milkshake like appearance (on the dipstick, under the oil filler cap or under the valve cover). This could indicate a failed head gasket/cylinder head. For now, just let us know how much you're losing and what other things you've seen.

Dave M
Dave M

[Ferret]

HOw much coolant are we talking about here? I'm assuming that since you've been through all these part replacements, and the system has been pressure tested, you haven't identified an external leak. If you're filling the resevoir daily and its headed straight out the heater core, you should be aware.

With the heat on, do you smell coolant (sweet smell)?

Does your windshield fog up or get a thin moist film on it just above the vent?

Is the carpet at the footwells damp/wet?

Is there a chance its leaking onto something hot enough to evaporate it? Its doubtful as the M50 exhaust is nowhere near coolant hoses and it sounds like you're losing quite a bit.

Its not rocket science, coolant doesn't travel any further back than the heater core, so if you don't find signs of an external leak, you might want to start thinking (and I hope you don't have to) about that coolant heading out your tailpipe or into the oil. Check your plugs for crusty white deposits, check the oil for frothy, milkshake like appearance (on the dipstick, under the oil filler cap or under the valve cover). This could indicate a failed head gasket/cylinder head. For now, just let us know how much you're losing and what other things you've seen.

Dave M
Dave M

Roll a knackered white sheet out under the car overnight and leave it.

If you've got a proper external/heater core leak, dirty water will land on it and/or stain it blue.

Does the car stumble at startup first thing in the morning?

I'm getting visions of my last M50 head gasket change here... as dave says, pull your spark plugs and see what they look like~!

[dacoyote]

Before you worry a lot... change the rad cap... and let us know how much you are loosing a day.