Explosion under the hood

[DRKREVRND666]

Ok here we go again. This car is a never ending problem, but i love it . So here is the latest. I have a 1996 318is with the m44 engine. I was sitting in the line at the emmisions station, because im about two weeks late getting it done because the check engine light was on and in maryland they wont even test a car after 1996 if the light is on. Well it went off so i went to the emmisions station and i was sitting in the line waiting my turn and BOOM there was a loud explosion from under the hood and alot of smoke. So i popped the hood and saw that the upper radiator hose had blown off and all the coolant had drained all over my engine compartment so i let it cool down for a hour and re installed the top hose refilled the coolant 50/50 mix and started the car it was fine until the car heated up and the it started leaking real bad from the bottom of the radiator on the bottom right side (if your standing in front of the car) im hoping there is a plug or something on the bottom of the radiator that has blown so i dont have to replace the entire radiator . I also noticed upon further inspection that the plastic piece that attaches the top radiator hose to the radiator had broken and was still in the hose. so what could cause the pressure to go so high that it blows the radiator hose off . and what should i do to fix it . is there a way to test if the radiator is no good or see if it is some small component that i may have over looked any help i greatly appreciated thanks.

[E36 Phantom]

Totally normal. It's all plastic sh!t. It experiences extreme temperatures - however cold your ambient temperature is at night, all the way to cooling down 230*F+ liquids. It turns brittle. If that's your original radiator, I'm SHOCKED that it lasted that long. If the plastic neck that the hose goes over is broken, it *will* pop off again, very soon. Matter of time. Basically, your radiator is toast.

[C Sean Watts]

Totally normal. It's all plastic sh!t. It experiences extreme temperatures - however cold your ambient temperature is at night, all the way to cooling down 230*F+ liquids. It turns brittle. If that's your original radiator, I'm SHOCKED that it lasted that long. If the plastic neck that the hose goes over is broken, it *will* pop off again, very soon. Matter of time. Basically, your radiator is toast.

The 'radiator test' was a fail when the BOOM happened. It's time for a new, updated one. Behr had a bad run for a long time - late 80s to late 90s. NOT just for BMW, every maker that they supplied. When you get a new (not a junk yard) piece check the neck sections where the hoses attach and you should see a thin metal band lining the inside. If you don't see it, DO NOT install that one. Save the receipt and return it for an updated one. The tank sections (side plastic pieces) were also improved some on them.

[DRKREVRND666]

Thats what i thought thanks guys any suggestions where to get one i was gonna get it from bavauto butim sure i can find one cheaper than 200$ but not by much

[C Sean Watts]

Thats what i thought thanks guys any suggestions where to get one i was gonna get it from bavauto butim sure i can find one cheaper than 200$ but not by much

That's about the same for my old Ford pickup.

[Pirate_copy]

Totally normal. It's all plastic sh!t. It experiences extreme temperatures - however cold your ambient temperature is at night, all the way to cooling down 230*F+ liquids. It turns brittle. If that's your original radiator, I'm SHOCKED that it lasted that long. If the plastic neck that the hose goes over is broken, it *will* pop off again, very soon. Matter of time. Basically, your radiator is toast.

Too true...too true

[nismosx08]

Ha! Exactly the same thing happened to me last weekend while attempting to take my car up Mt. Washington. Seemed to be more bad timing than the extra load, techs think the thermostat got stuck shut allowing extra pressure to build up on that side, also the plastic elbow was indeed broken as well. Luckily i was only 3/4 of a mile up and got my money back. Was able to get it halfway home, had it pop off again and had it towed to a shop that was able to fix it next day, provided i drove over an hour from where i was staying to the BavAuto Showroom, a place I never thought I'd get to visit (pretty nice actually) Got the aluminum housing, 88 degree thermostat, upper and lower hoses, new behr radiator, 7 quarts of redline oil (to replace what burned while i was overheating on the half-drive home) and oil filter for $334. A bit frustrating but you grow from new experiences...or something. Odds of this happening to both of us within a week and me actually getting around to reading the new posts? slim, very stange, kinda made my night

[bimmerblack]

Damnit, looks like ill probably be havin to call the guys at Bavauto AGAIN before the spring break trip to padre...cos im not entirely sure my radiator has been changed in its 150,000 miles, and i DON'T want to be three hours or so from some kappa/chio/miscelaneous hot chicks, when that thing decides to go

[E36 Phantom]

Thats what i thought thanks guys any suggestions where to get one i was gonna get it from bavauto butim sure i can find one cheaper than 200$ but not by much

Dude, if you can get it for $200 you're doing fine.

[Pirate_copy]

$200 for a radiator is CHEAP...isn't it?

[E36 Phantom]

$200 for a radiator is CHEAP...isn't it?

Yessir. Not a bad price at all. I'd jump on it.

[Pirate_copy]

I paid $500 for mine (not a BMW dealer)

I know i am in the UK, but the prices do not have THAT much of a difference :)

[jasonf860]

$200 for a radiator? I paid $128 for mine last year from a local radiator shop.

[nismosx08]

for your 89 accord? sounds about right

[DRKREVRND666]

I found one at a local radiator shop and installed it and it blew a week later something is causing this thing to build pressure and is blowing my cooling system up by the way i payed 150 for the new radiator

[nismosx08]

check the thermostat housing, I heard about a manufacturing problem where holes that were supposed to be drilled just weren't there, causing the same problem...Could also be a blown head gasket allowing the lost compression pressure to leak into the cooling system over pressurizing it, that's what my mechanic suspected had happened to mine...luckily he was wrong

[E36 Phantom]

Well, first of all, was OEM? Was it new? Are you sure it was installed correctly? I hope you didn't pay $150 installed, cuz I'd say that's your problem if you did.
What exactly blew? Take it to a BMW mechanic and have them diagnose. There could be several things causing this.

[DRKREVRND666]

The radiator was after market and the whole reserve tank and the plastic housing that is actually the side of the radiator came off i took it back and the guy i bought it from gave me a new one i installed t mt self and bled the system . I also did a pressure test on it it held to 16lbs before i stoped i also did a compression tes on all four cylinders and each was between 150 and 160 i think thats good so im ruling out head gasket but my aux fan isnt coming on so either i need a new temp switch or theres another problem i cant figure what it is . Besides a bad temp switch or a air bubble in the radiator what else could cause the fan not to work . I jumped the fan an it works so thats not the problem any other ideas

[sillycar]

i once turned the car over, there was a boom and smoke, it was at night, i thought a headlight blew up

turned out, we just had to reattach the hose, no big deal, no change needed happened 3 months ago, runs everyday now

i also once changed my radiator on my old 86 celica, it had a hole and smoke/vapour would build up under the hood at lights. i left it like that for a while for fun then got one for $50 from the junkyard, surprised to see any 86s around too bad never a bmw in scrap

[C Sean Watts]

I paid $500 for mine (not a BMW dealer)

I know i am in the UK, but the prices do not have THAT much of a difference :)

In the USA we don't have VAT.

[DRKREVRND666]

i worked on the car some more today i did a switch test on the fan switch i also checked power supplt to the switch and the relays the high speed relay had power to one of the terminals on the relay but not on the other i really need top find out why this fan isnt comingon im changing the switch on monday but if that dosent fix it what the hell else could it be ive checked every thing it didi this before but that was because my coolant was low that definatly isnt the case ive blead the system three times and its pefrect the pressure in the cooling system is rite around 18lbs has any one else had this problem with the m44 engine and could any one give me any suggestions.

[Bimmer325]

water pump and/or head gasket check that sh*t out. my radiator hose blew off and it was becasue of the water pump which caused my head gasket to go because it built up pressure and the radiator hose went.