Coolant going low - BMW Forum

moe19x · 10-03-2006, 02:05 PM

Hey guys i have a 98 328i for the last week or so my coolant light keeps coming on and i have to keep adding coolant. So far my oil looks normal, car isnt over heating, no white smoke coming out of the exhaust. cant see coolant leaking, where could it be going?? i did have my rad changed this summer. any ideas on what i should check? thanks

WarNox · 10-04-2006, 08:19 AM

if you keep on adding it and it keeps on draining, it must be leaking somewhere. wait for the car to be cool and have a good look all around the engine. if you can't see anything, turn the car on and look again.

good luck.

kylek325i · 10-06-2006, 11:27 AM

check all around where the coolant flows- thermostat, water pump, rad, water valve etc. make sure you add coolant when the car is cold. Try turning the heat on hottest setting and see if you smell anything, if it smells sharp and sweet- this could be your heater core. My cars leaks but havent replaced it yet cause its a major PITA. I have to add a little bit every so often; but its really not a significant leak. Also, make sure your system if completely bled of air.

98three28i · 10-06-2006, 10:02 PM

two months. Keep us updated as to any findings.

Furious · 10-07-2006, 03:52 AM

the best way to check for external leaks is to put a piece of cardboard under the car when it sits. both when you stop driving (still freshly hot) and even when its been sitting for a while. if you yield no results you can also get the technician to check the oil on the next oil change to see if any traces of coolant are in it.

moe19x · 10-07-2006, 11:09 PM

I did notice some coolant not where you add the coolant but at the opposite end of the rad. but the next day there was none but there is dry residue there. i actullay say the coolant there on 2 occasions, ill try taking a pic to show what i mean, i havent noticed any on my driveway though, im kinda worried what are signs if it is in the oil?

Furious · 10-10-2006, 03:12 PM

could be the where the plastic end tanks meet the aluminum rad itself. or you could have a crank in the spigot, however take some pics it will help us resolve this. get some good pics too so we can all see where it looks like the leak is coming from.

SHAHAB323IS · 10-10-2006, 07:11 PM

that's where the radiator drain plug is, it could be cracked, you're only supposed to tighten it a little, and it could have been over tightened, it's only supposed to be tightened 18-27 in pounds, that's INCH pounds not foot pounds, so you might want to check that out

moe19x · 10-10-2006, 10:04 PM

thanks guys ill be checking it tomorrow morning for sure, i added some coolant yesterday and checked it Today but it looked like it was at the same level

jim325i · 10-11-2006, 07:40 PM

i had the same problem and i would guarentee it is the heater core at first there was no sweet smell for a good 6 months and i would have to add coolant every 3 to 4 weeks then it started to smell worse until it was spuing smoke thru the vents i just changed the hater core over the weekend it is a pain it took 5 hours but was well worth it.

moe19x · 10-15-2006, 10:02 PM

hey guys here are some pics. it seems like every few days i need to add 1 cup of radiator fluid. ive included pics of my oil cap, dip stick, and where i think it could be leaking from. also on the side of my rad there is a plug which im not sure what its for but it dosent seem to fit in properly. thanks in advance guys

dont worry about the dates in the pic, i was in a hurry and forgot to set them in my digi cam

moe19x · 10-18-2006, 11:26 AM

come on guys ive posted pics i need some help please

moe19x · 10-24-2006, 11:40 AM

please guys this thing is driving me nuts. how can i check to see if my heating core thing is messed. plus what the hell is that plug on the side of the rad, it wont plug in for some reason

bitcore · 10-26-2006, 07:07 PM

oil appears fine, headgasket should be ok.

check the hose neck where that hose connects to the radiator: they are infamous for cracking\completely failing and leaving you stranded and needing a new radiator. - ask me how I know.
Look under the neck on the plastic for hairline fractures and anything out of the ordenary, try to resist the urge to torque down that compression band, that will probably make the problem WORSE unless it is just simply very loose, in which case I'm surprised it hasn't poped off yet. If it's cracked, get it replaced, if it's leaking FROM the hose where it joins up to the radiator, loosen the metal band all the way and pop off the hose, try to be gentle. Then examine the neck for any damage or broken plastic pieces. - if anything's really cracked, use your own jurisdiction to replace the radiator.

I believe that is a temperature sensor, but I think it's suppose to be on the other side of the rad, not sure.
what do you mean it wont fit? the electrical plug?

wanna trade engines?

Dudesky_E36 · 10-27-2006, 04:47 AM

That's the temperature switch for the auxilliary fan. This may be why you're losing coolant; you may be running a little hotter if that thing isn't plugged in. There are 2 types: a 2pin and a 3pin switch. Maybe it doesn't fit because you have the wrong switch installed on the radiator?