overheating - frozen thermo? heater valves?

[timandbim]

i'm so glad this happened today and not yesterday.

we just got almost 3 feet of snow here and it went down to around -18'C (zeroF i think) last night - i also just put 1200km on the car over the weekend and drove through a fair amount of snow. no hiccups at all, except when i got back i had to dig myself a parking space for four hours with a pos shovel.

today it's been around -5'C and when i went to start the car i ended up flooding it because my icv valve had frozen shut. so i took it off and thawed it and everything seemed to be working great again. but after a very short time the temp guage started to get so hot i had to turn it off. i eventually got it back home (in total i drove about 10 blocks, although it's slow out there so i was idling a lot and the car was running for about 20 minutes) but i wasn't having nearly as much fun driving it as i usually do as the needle approached halfway through the red zone.

i started it again just now to see what it would do just idling up to normal temperature and it does the same thing- gets hotter and doesn't reach a ceiling (or one that i'd be willing to let it reach)

so something must be blocking the coolant flow right? thermostat? but all three pipes by the radiator are getting hot (the top ds gets a bit hotter than the other two) and i'm not losing any coolant. and wouldn't it thaw open? or maybe it just crapped out after the long drive. i think this is a big clue- i'm only getting cold air into the cabin - worked great yesterday.

this is my first winter with the car- i think it spent most of its life in a garage but now it is (and i am) getting a taste of reality bites. i've spent ALL of my spare time since i bought it trying to get it ready for winter (with all of your help!). i read the section on stuck heater valves on the e34net page could that be the problem? if so, could someone please recommend some lube i could use on those and inside the icv that won't turn into crud or freeze at -1'C? i used to use only white grease and wd40 on my old car, but that was my old car and now i actually care. i'm a dork for not checking the radiator cap (i could see the coolant level through the overflow tank) but there was no spillage or leaking - could a loose or broken one cause those symptoms, too? i'm going to spend some time out there tomorrow, so if anyone can think of anything else i can look for or has any ideas i'd much appreciate it. thanks.... again!

[timandbim]

i have taken it to a garage round the corner that opened last week - only one in driving distance for me. i can't even make it to the closest reasonable parts store which only delivers to garages anyway. they are still moving equipment and will do a compression test for me when the gear arrives today. replaced the thermostat yesterday - no change. the old one looks pretty much new (gasket too) which i'm hoping is a sign that i didn't do any major damage on the overheat. checked the fan blade and there is some resistance to it turning so i think the fan clutch works ok.

i'm hoping it is the water pump or an easy-to-find clog somewhere. would coolant still circulate even if the heater valves weren't opening? the radiator looks to be in excellent shape and all the hoses seem almost new. btw the ac is obviously screwed and i've never used it. i checked the hoses when it was running again and the top ds hose is hot near the thermostat but cold near the radiator. there are no coolant leaks that i can see.

i've never experienced an overheat before and i am terrified that i let it get too hot. the car still seems to run great otherwise - exactly as before. the needle got about half-way through the red-zone (i was REALLY stuck in traffic) the one time and since then has never gone above the 3/4 mark. there were no clouds of steam and i didn't smell anything burning or melting but it did pop the safety-cap on the expansion tank.

it warms up normally, but just doesn't stop heating up - it happens pretty quick, and i only get cold air through any of the vents.

if anyone thinks i phXXkd the HG or anything else i sure would like to know - any ideas would help. sorry this is so wordy i'm just trying to include anything pertinent i can think of.

[BigKriss]

you can just bypass the heater valves. i'd look at the water pump and thermostat first. maybe the hg is rooted. only time will tell.

[vince]

Have you changed the coolant since buying the car? It sounds like there is a problem with coolant freezing because it isn't mixed correctly for the temperatures you're seeing. I had this happen with a 325iS I bought.

hope this helps,

vince

[repenttokyo]

The amount of snow we got this week was RIDICULOUS, here is my gf's car on monday morning:

[timandbim]

so... exhaust in the coolant :(
i'm trying to figure out how this happened b/c the motor looks practically new like the p/o said so i'm assuming the headgasket was new too.

Have you changed the coolant since buying the car?
when i bought it i changed the coolant right away (although hmmm i did use the green stuff - i didn't know and the stuff in there before was green). i check it veall the time as i have bypassed the busted coolant level sensor. until this week i hadn't lost a drop- according to the expansion tank level at least and my temp guage never ever wavered from dead-on noon. but when they drained the coolant only 5L came out. i didn't notice any white smoke but i wasn't looking for it and there is a lot of steam and white snow around these days.
when everything is off i'm going to look at the water pump and see if it looks brand new like everything else (thermo, rad)... maybe i should replace it anyway- but this car seems to have a completely new complete cooling system. would somebody have changed the radiator, hoses, MOTOR, timing belt, etc and left the old water pump in?????
this is driving me nuts- could i have done this by (gulp) putting the radiator cap on wrong after checking it? now that could be the worst move ever- it was off at an angle after the overheat but i think it's supposed to do that to release pressure... right? i never saw any steam coming out from under the hood and i wouldn't have missed that! i guess all kinds of things can happen in these crazy conditions. anyway i'm hoping i haven't done any more damage to it that i can't afford to fix- this really sucks.


The amount of snow we got this week was RIDICULOUS
snow removal trucks in ndg the day after a snowstorm??? when i used to live there it seemed to take a week for the snowploughs to arrive. by the time they did, everyone was too snowed in to move their cars out of the way!

-oh jeez- the garage just called - told me autolectra (the only reasonable parts store i've found in town) sent the wrong gasket (they screwed up already delivering the thermostat)- now i'm going to have to buy the parts from their supplier which is going to be twice as much. they say i need a water pump too and an 'intake gasket' don't know what that is will check it out i'm going down there now. certainly stuck there considering the whole engine is in pieces. must have been the water pump that caused this whole mess. could be worse... i guess...

[Ross]

The water pump diagnosis fits the symptoms. If your engine was an M50 I would have pointed to a bad water pump impeller right off. The later M50 water pumps are notorious for the impeller breaking.
Good time to change the timing belt on an M20.

[repenttokyo]

snow removal trucks in ndg the day after a snowstorm??? when i used to live there it seemed to take a week for the snowploughs to arrive. by the time they did, everyone was too snowed in to move their cars out of the way!




nope, they didn't come until LAST night.

[timandbim]

i can't believe the p/o changed the motor and the radiator and the whole cooling system without changing the water pump. it's not off yet but it's obvious it hasn't been changed forever. why would you skimp on that when everything else is brand new?!?

looks to me like i didn't do any more damage than that. it's going to cost me 8 hours (plus the super-inflated parts which arrive and are for the wrong car) which i think is pretty reasonable. the old hg is definitely melted in places but not too bad and it looks like i turned it off before doing anything really serious. actually i'm counting myself pretty lucky for a few reasons... a)these guys moved in like 2 weeks ago round the corner and there's no way i could have made it to any other garage b)considering i've never experienced an overheat before i think i could have done way more damage - it happened so fast i might not have noticed and c)this could have happened 500km away in toronto! boy did that weekend underground parking pass ever pay off!

so while everything is apart- anyone think of anything else i could look at? (not the a/c- no way i'm going there yet!) all the belts and hoses look brand spanking new (timing belt too thanks Ross)- never had a spark problem- nothing but 1444 since i changed the oxy sensor. i have some difficulty with warm starts sometimes but i'm sure that is just the common valve fix which can wait.

i've put almost $5000 (that includes tires and bodywork) into this car since i bought it for really cheap in july. i knew about a lot of it in advance and was guessing around half that but i still think it's worth it (god i love driving it!) so long as in the future i'm not going to miss the little details and destroy my car if i'm stuck somewhere i can't kill the engine for 5 minutes. i've done nothing but read about e34s for a long time now but i sure hope i haven't missed anything.... i have a job but it only pays so much- when i can get there!

[timandbim]

nope, they didn't come until LAST night.

i guess the truck in the photo was on it's way back from westmount- it's no better here- i'm kind of glad the car's in the shop. (...kind of...) :(

[Dave M]

Are you getting the head pressure tested? I don't want to alarm you, but if it has cracked during the overheat, you want to find out now, rather than after you've paid the bill. A cracked head is less likely as you've seen obvious head gasket damage (hopefully taking the majority of the overheat), but for peace of mind...........

I agree with Ross. As you had no heat in the cabin and an overheat, I suspect the water pump. Its an expensive reminder to never drive once you've noticed the needle going north, but it could be worse.

If it makes you feel any better, which I'm highly doubting, I've replaced my M50 head and block (twice) on seperate occasions :D

Hoping your christmas holidays get better,

Dave M

[timandbim]

Are you getting the head pressure tested? ...........

I agree with Ross. As you had no heat in the cabin and an overheat, I suspect the water pump. Its an expensive reminder to never drive once you've noticed the needle going north, but it could be worse.

If it makes you feel any better, which I'm highly doubting, I've replaced my M50 head and block (twice) on seperate occasions :D

Hoping your christmas holidays get better,

Dave M

thanks Dave- i'm actually feeling lucky to have not done worse and i'm pretty happy with this mechanic. i asked if there was damage to the head and he said no but i will maybe be more specific tomorrow. he's been bang-on so far though... said it was the hg before he saw it. 8 hours is pretty reasonable for everything. the younger mechanics who are doing the work are pretty excited about working on it and the motor looks awesome- not a piece of black anywhere everything's super clean. they don't mind me hanging around and i might try to hook up my mirror controls on my new door tomorrow while it's out of the cold if they don't mind.

errr... i was REALLY stuck in traffic and snow. all i could do was sit and sweat. it happened really fast - like five minutes max from me seeing it and it hitting red. assuming this was the pump that did this -those of you that haven't might want to take a peak next time you're down there- just a suggestion.

[bmwpower]

Subscribed. Mine is doing something kinda similar but not getting as hot as yours.

My water pump is brand new, so I'm gonna be pissed if it's the water pump.

I don't think I read it, but when it was getting hot did you test the lower radiator hose to see if it was cold?

[timandbim]

Subscribed. Mine is doing something kinda similar but not getting as hot as yours.

My water pump is brand new, so I'm gonna be pissed if it's the water pump.

I don't think I read it, but when it was getting hot did you test the lower radiator hose to see if it was cold?

trust me you'll be way more pissed if it's your headgasket.

it was weird actually- kept changing every time i tried it. i'm guessing sometimes the exhaust made it past the thermostat and sometimes not. it heated up really fast though and never slowed down. i think the pump and the headgasket packed it in seconds apart.

i dunno if i can suggest anything helpful. other people on here would know way more but i would say if you're getting cabin heat your pump's ok, no harm in changing the thermo (my goldfish could probably figure it out), and how old is your rad?

[aston_jag_tech]

Buy a block tester from a parts store, Use it and then replace the head gasket.