E36 radiator "overflow" problems?

[Nick]

Either I have some weird problem with the cooling system - or I was just dumb enough not to put enough water in the beast. Tell me which...

I noticed earlier today it was puffing steam from a little "X" cross next to the radiator expansion tank . Didn't think much of it, being an E36 newbie 'n all - guessed it was some cunning Germanic engineering at work. Had the car a week so still gettin' used to it.

However, later on... cruising along... the temp starts going up rapidly. Red light came on, so I powered off & pulled over (fast). Hazards on, bonnet up. Very annoying.

A liter or so of water - thankfully had some in the car - was enough to get me off the AYE. After it'd cooled a little, it took fully about 5 - 6 L of water - and then some more. Restarted - no puffing, temp seemed OK, was able to drive another 10 - 15kms with no apparent issues.

So my question - does this sound like some known issue - e.g. is there a valve that's known to fail, letting off steam uncontrollably in the process, or is it a case of dumb-ass driver? There are no obvious leaks from hoses or the radiator itself, and the oil is still OK (not milky). Any ideas?

 

[gwumpkus]

Re: E36 radiator "overflow" problems?

mate, that is the bleed valve- the little cross-headed "screw" on the TOP of your radiator, next to the reservoir cap, i assume??..

and its supposed to be SCREWED IN.... its NOT suppose to be open in normal operations, otherwise, the water's gonna run out... maybe that explains why u're losing "steam" ie. water..

top it off (50-50 mix of coolant/water), tighten the screw down..(as with most plastic screws, dun overtighten, or u;'ll brak something!)..

hope this helps..

cheers!

 

[sszone]

Re: E36 radiator "overflow" problems?

more towards the dumb-ass driver portion....hehe
but hey, i was one dumb-ass too where i got my beemer.
had the same prob like u...hehe
end up calling my car dealer who was damn service oriented, came all the way down from ubi to help me..
the sop i learnt was unscrew the x, unscrew the reservoir cap....drown the reservoir side with water until water comes out of the x.....screw back the x, close reservoir cap
anyway e36 prone to radiator leakage, bought myself some radiator leakage formula thingy....dumped that into my radiator and solved the prob

 

[gwumpkus]

Re: E36 radiator "overflow" problems?

hahh... this radiator bleeding process is really crappy by german standards!!!..imagine, u have to top up ur rad, start ur engine, peep at the damned water level with the reservoir cap OFF, keep adding water till the water comes out of the aforesaid bleeding screw, spilling EVERYWHERE and making a green/blue mess..... before u know that ur bimmer is sufficiently hydrated!!!.. i say someone had a pint too many when they designed this!!..

still..i hope our rantings about the radiator helps our friend to solve his prob..



cheers!

 

[Nick]

Re: E36 radiator "overflow" problems?

Thanks guys. Yeah, I noted that it tends to bubble over like a lava flow, gurgling green ooze over the expansion tank. While not elegant, I am at least reassured that this is (somewhat) normal.

So the trick is to over-fill then let it get it its own state of natural harmony? How low should it go - seems to drop a bit down the tank (when warm) but them come back up (when cold).

Being Nervous Nelly over this, but an overheating engine in an old car in a hot country is not a pretty scenario...

Actually its at BVO right now being pressure tested - just to make 100% sure there's no small leaks or hairline cracks, etc.

 

[gwumpkus]

Re: E36 radiator "overflow" problems?

nope..the trick is to top up the radiator reservoir, with engine running, bleed screw loosened, till the green oozze has had its way... cut the engine...go watch a movie and grab dinner...
return to car, engine's now cold, top up to the line indicated in the reservoir tank...

what u've done, is to release the air from the system, and when filled up to the "KALT" line indicated on the reservoir, the water levels would be enough by bmw's recommended levels...

usually i throw in half a bottle of Purple Ice to help the 50/50 mix...
and i only use bmw's coolant.... not exp, like $6.50 a bottle or something...my humble 4-potter uses 2 bottles of coolant with 2 bottles of water in a 50/50 mix for a complete flush..

 

[Bmmad318i]

Re: E36 radiator "overflow" problems?

gwumpkus,

Just wondering if its necessary to use back the BMW coolant or also can use any generic brand of coolant?? Is there any detrimental effects if using other generic brand of coolant?? Just wondering....

 

[ersalle71]

Re: E36 radiator "overflow" problems?

To be on the safe side, use back BMW original coolant, costs only $8, get i from Eng Soon. Before that flush the water inside the radiator and engine block, drain it and refill back. Nick u had ur engine hit the red mark on the temp gauge, under normal circumstances it is advised u do top overhaul and replace the head gasket to be on the safe side, the head gasket is burnt already.

 

[ersalle71]

Re: E36 radiator "overflow" problems?

Opps i didnt read the below thread, u did do pressure test huh. Then it should be fine ehheheheh

 

[Nick]

Re: E36 radiator "overflow" problems?

Opps i didnt read the below thread, u did do pressure test huh. Then it should be fine ehheheheh

Really? It hit red literally for a second before I powered off & coasted. BUT still, I take your point. Will consider.

FYI, am fitting new (reco) water pump + thermostat. Had new hoses within past 2 years.

With radiator, does it tend to fail spectacularly (e.g. dumping coolant all over North-South Hwy then cooking the block) or does it more tend to crack, leak then finally fail more significantly?

 

[ersalle71]

Re: E36 radiator "overflow" problems?

Prolong overheating, for e.g temperature gauge at 3/4 mark all the time will eventually warp and crack the head block, this happen to mine. By the way what engine is your ride?6pot or 4 pot? New water pumps cost only $70-80 why are u using recon waterpumps?sheeshhh Well if u said it only hit a mere few seconds then the head gasket may survived from being cooked. Small leakage from radiator and hoses normally makes ur temp gauge move up slowly and u can see it when u stop or crawling at traffic. Normally it wont fail spectacularly, its more gradual until theres no more water in the head block to recirculate thats where ur temp gauge jumps to red.

 

[Nick]

Re: E36 radiator "overflow" problems?

Prolong overheating, for e.g temperature gauge at 3/4 mark all the time will eventually warp and crack the head block, this happen to mine. By the way what engine is your ride?6pot or 4 pot? New water pumps cost only $70-80 why are u using recon waterpumps?sheeshhh Well if u said it only hit a mere few seconds then the head gasket may survived from being cooked. Small leakage from radiator and hoses normally makes ur temp gauge move up slowly and u can see it when u stop or crawling at traffic. Normally it wont fail spectacularly, its more gradual until theres no more water in the head block to recirculate thats where ur temp gauge jumps to red.

Nah man, its not reco - new pump. I aint that cheap! And besides, the whole point of it is pre-emptive maintainence on a component known to fail. So need new pump to achieve that.

From what I've seen so far, temp stays rock-solid throughout. If it was at 3/4 for sure I'd be worried also.

BTW, is there such a thing as an electric fan (vs. engine driven)?

 

[ersalle71]

Re: E36 radiator "overflow" problems?

Electric fan vs engine driven.......why? electric fan are mostly on FWD cars because of the engine postioning. RWD cars normally uses engine driven to draw in air. If u want to convert to electric fan, u will free some engine load but at the expense of ur battery power. There are pro's and cons about this. Our car still have a push fan that is in front of the air con cooling coil, its on when u turn on the aircon, and if the air con is off it will turn on at slow speed when the thermoswitch in the radiator senses water temperature is slightly above normal operating temp.

 

[Nick]

Re: E36 radiator "overflow" problems?

Electric fan vs engine driven.......why? electric fan are mostly on FWD cars because of the engine postioning. RWD cars normally uses engine driven to draw in air. If u want to convert to electric fan, u will free some engine load but at the expense of ur battery power. There are pro's and cons about this. Our car still have a push fan that is in front of the air con cooling coil, its on when u turn on the aircon, and if the air con is off it will turn on at slow speed when the thermoswitch in the radiator senses water temperature is slightly above normal operating temp.

That's basically it - free up a little more power. Engine feels a little strangled when fan is running. But guess it’s not essential.

At this (early) stage I'm trying to remain focused on basic preventative maintenance.