M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: arcter on March 24, 2010, 05:14:18 PM
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Hey guys, I think I'm noticing some coolant loss and I'm trying to figure out where it's going. I recently had the radiator completely replaced because the shop noticed a small leak. Anyway, I just filled up the coolant to the halfway mark last week and it's already taken a pretty big dip (about an inch). I don't notice anything on the ground and I don't notice anything in the engine bay that looks wet. Car runs fine. Also don't notice anything milky on the dipstick or oil cap. Any ideas?
By the way, I noticed the suggestion to have the cap open and let the car warm up with heater fully on. My heater doesn't work so I skipped that step this time. Should I try it without the heater?
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Could be an improper bleed or maybe one of the hoses under the intake is leaking a bit. Why doesn't your heater work? Hopefully its not a heater core leaking, although I'd think you'd see some coolant drops on the ground from the drain.
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Could be an improper bleed or maybe one of the hoses under the intake is leaking a bit. Why doesn't your heater work? Hopefully its not a heater core leaking, although I'd think you'd see some coolant drops on the ground from the drain.
I'm not sure about the heater, it may be the heater core. I don't notice any drops though. The car leaks nothing onto the ground except for a drop or two of power steering.
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Still no drops on the ground but it's still losing coolant. Nothing in the oil.
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My coolant leaks a tiny bit from somwhere under the intake manifold, I think it is the small hose coming out of the cylinder head. Anyways, it lands on the "shelf" of the block and puddles temporarily near where the transmission meets the engine, then gets burned off after the car runs just a few minutes. If you don't look there specifically when it is leaking you'd never notice it except that it leaves a chalky residue on the "shelf".
I'd wait to see if it keeps leaking, it took mine a couple of weeks to stabilize at the "kalt" line after I changed my coolant. I couldn't tell you why though. Maybe I bled it wrong, I'm pretty new at this, but haven't really had any problems since (except for my tiny leak which I can't seem to correct)!
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Thanks for the response. I keep adding a bit to get it up to the kalt line but after a few days it goes down a couple of inches. Hopefully it's just a small leak and nothing serious... I've been having bad luck recently. :(
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Yikes, that's a lot. Do you ever smell it? I guess if it's not dripping on the ground it's either ending up somewhere it shouldn't or being burned off by landing somewhere on a flat part of the engine.
I'm really a novice but I filled my expansion tank to the filler cap basically in order to get the air bubbles out and over the course of a couple of weeks it got down to the kalt line and stayed there. There's probably something wrong with mine though because the level doesn't drop when I turn on the heat for some reason. Probably didn't bleed it right but my remperature gauge stays in the middle so didn't mess with it anymore.
I'm curious what it is though in case you find it...
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I don't know if I ever smell it. I smell mostly exhaust, been meaning to look into that soon. Not the "sweet" smell usually associated with coolant. I recently had the radiator replaced because my shop said there was a small leak. Ever since then I've been noticing the coolant level dropping... I'm going to bring it into them tomorrow if I can and have them check it.
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If you're certain there's no coolant in the crankcase and you don't have a perpetually steaming exhaust, I'd say the shop didn't observe the proper coolant capacity for your car and under-filled it. Air bubbles are finding their way back to your reservoir and your coolant level's dropping accordingly.
I've found that pumping (repeated squeezing) on the upper radiator hose near entry into the engine while it's running and warm is a good way to get air out of the system. It takes repeated pumping and filling to get the full capacity in there, and leave your heater on while you do it. If your car is an e30 it should take just under 7 quarts to fill the system (including heater core) to it's proper level.
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If you're certain there's no coolant in the crankcase and you don't have a perpetually steaming exhaust, I'd say the shop didn't observe the proper coolant capacity for your car and under-filled it. Air bubbles are finding their way back to your reservoir and your coolant level's dropping accordingly.
I've found that pumping (repeated squeezing) on the upper radiator hose near entry into the engine while it's running and warm is a good way to get air out of the system. It takes repeated pumping and filling to get the full capacity in there, and leave your heater on while you do it. If your car is an e30 it should take just under 7 quarts to fill the system (including heater core) to it's proper level.
Ryan,
Yeah, I'm not noticing anything coming out of the exhaust. How do I become certain there's no coolant in the crankcase? I haven't noticed the 'chocolate milk' oil in either the oil cap or on the dipstick. I think your explanation makes sense though, because I didn't have this problem at all before the radiator was replaced.
But I'll have them look at it tomorrow since they'll probably do it for free anyway. By the way my heater doesn't work so that's another potential suspect from what I hear?
Thanks!
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If your heater doesn't work I'd say they definitely bled it wrong. I'd keep it away from them and do it yourself.
Next time you flush & fill (After draining the coolant from the radiator, engine drain and heater core hoses):
Make sure your heater is set to full hot.
Pull both hoses off the engine, fill them both up as far as possible.
Pull a heater hose & fill that up too.
Button it all up & run it. Helps to have the nose pointing up...use a steep driveway, hill, jack stands or even ramps.
While it's running I loosen the radiator bleed screw (very carefully with a large straight-bladed screwdriver) until the coolant flows out with no bubbles.
If you have coolant in your oil you'd know it very quickly, it's very easy to see. Better that you checked though...some find out about it after they spin a bearing or throw a rod.
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Hey guys. Thanks for all the replies. Shop did a pressure check and everything came back fine, it held pressure. Only leak is the power steering. Am I imagining my problem?
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Could it just be some loss to some steam escaping? or maybe just an ambient temperature change causing the level to change some? I know my 530i has a phantom coolant leak that causes the coolant low light to come on every few months or so. I cant find the leak anywhere, so I just figured it was escaping as steam from an overflow or pressure release valve or something like that somewhere in the system.
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If you have no heat the car isn't bled properly. Should be exactly like it was before the radiator was replaced. It'll hold pressure just fine, but if you don't get 99% of the air out the heater will not work. The heat should be uncomfortably hot from the vents if the system is in good shape.
Hopefully the shop did it right this time. I don't want to come across as a hard-ass here, but this particular BMW is a PITA to bleed and if it overheats for more than ten seconds you'll need a new head.
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Well my heater hasn't worked since I bought it months ago, and this radiator was changed a few weeks ago and the heater still does not work.
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Maybe it's the valve then. If you look next to the gas pedal you can see it under the dash, right behind side of the center console. There are two types, the metal and pastic ones. They're not that hard to replace, maybe just a bit tedious. Here's a good writeup over at r3v:
http://www.r3vlimited.com/board/showthread.php?t=98782
RealOEM diagrams:
http://www.realoem.com/bmw/partgrp.do?model=AJ93&mospid=47318&hg=64&fg=15 (http://www.realoem.com/bmw/showparts.do?model=AJ93&mospid=47318&btnr=64_0514&hg=64&fg=15)
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Thanks Dave. Would it be just the valve and not the heater core itself?
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I'd figure the heater core would give you a visible leak & powerful coolant smell. The valve not turning seems more likely to me.
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Check the area just above the A/C pump bracket where the head meets the lower timing chain cover. If water is leaking out of that area you need to replace the Timing Chain Case Profile Gasket. Its kind of a big job.
http://www.m42club.com/forums/showthread.php?t=11162
P
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Just pressure test the cooling system and see if any coolant leaks out.
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Yeah the pressure test came back fine :/!
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I've noticed that my coolant level has dropped an inch or so below the cold fill mark. Its been maybe a month or so since I filled mine. I think some loss is normal (the heating and cooling and losses through vapor)
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Coolant loss is not normal in any circumstance. The only way for water loss is through a leak in a hose, leak from a gasket, leak from a radiator, heater core, faulty radiator cap.
Once the water is in there it should stay. Water vapor is not lost into the atmosphere, it condenses back to liquid within the cooling system. The vapor pressure of water is raised due to the system being a closed system, under pressure, and the thermostat opening below the boiling point of water. (212 degrees)
If your level is dropping you have a leak or you are overheating and the system is letting off the pressure.
Make sure you do a pressure test over time. It would take a very long time to see a small leak in a pressure test.
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I had one that lost about 1qt per tank. The head was warped about 008. ran fine , the oil got milky after 2 months.
MM