Just popped my cooling system cherry

[cornflakecwl]

OK, so I'm on my way to the gym, looking for a parking spot, in a good mood, car is driving nice, the guibo/mount and fresh oil change yesterday. COme to a light all of the sudden see white smoke all around me, shit downtown Toronto, nowhwere to stop. Finally get turned around to stop and look, rad hose off, the plastic on the rad that the hose goes onto snapped. UNdo the hose clamp, tighten it on what is left, luckily I had some coolant in the trunk, fill it up as best I can, make it home stoping twice for 10 minutes to shut it off and let it cool. Now with no coolant the highest the temp gauge got was about the 3/4 mark. I am hoping I didn't warp the head? Car is gonna have to sit for a few weeks until it gets warm enought to change the rad and hoses myself cause I am NOT paying someone else to do it. So what GOOD aluminum rads are there out there for m50 e34? If I am gonna do it, rather do it right once as this car will eventually be getting m52/s52 cams and probably FI. Suggestions please!!

And so much for my clean ENGINE!!! GRRRRR!!!!!

[RobertV1]

Sorry to hear about the failure and I hope you head is OK too.
This is what I have been told to use:
http://www.zionsvilleautosport.com/store/screen/prod/store_code/6134/product_code/E34V8AR.htm
I don't have any personal experience with them yet, but have heard all good things.

[pennpen]

yeah same thing happened to me, still clamped onto whats left but i always have coolant and tools in my trunk

[cornflakecwl]

Nice looking piece, only lists for 530/540 tho. Not sure if it would work with M50.


yeah same thing happened to me, still clamped onto whats left but i always have coolant and tools in my trunk
How hot did yours get/how long did you drive before you realized and was it ok? I'm not dirivng it until I get new rad, t-stat, wp and upper and lower rad hoses. Rather not get stuck again and at least I know the cooling system is good for a long while after that's done. Might not go for the alum rad right now tho, don't really have the cash. I can get OEM from my usual place for $275 not too bad. WIth wp, tstat, hoses and gaskets looks like I should be out the door under $500. Not too bad. What brand metal impeller water pump does everyone use?

[bigwig023]

I don't think you should worry about warping, I know the m60b40 is a different motor but I've hit the red and some at least 5 times last summer. It was really dumb, but there is a crack in my block so I wasn't overly concerned about it over heating. Damn rush hour traffic and a bad water pump..... Engine still runs, not perfect but it always starts...doing a motor swap in the near future

[bigsixe34]

If you didn't get past 3/4 you can be almost positive the head is fine - that kind of reading is common when bleeding the system of large bubbles as well.

[cornflakecwl]

I don't think you should worry about warping, I know the m60b40 is a different motor but I've hit the red and some at least 5 times last summer. It was really dumb, but there is a crack in my block so I wasn't overly concerned about it over heating. Damn rush hour traffic and a bad water pump..... Engine still runs, not perfect but it always starts...doing a motor swap in the near future


If you didn't get past 3/4 you can be almost positive the head is fine - that kind of reading is common when bleeding the system of large bubbles as well.

Very glad to hear that, I figured I was ok, thanks Gents. Just putting price list together, should I be going for 88 or 92 degree thermostat? Live in Canada, cold winter, moderately hot summer. I am thinking 92 is prob better?

[bimmerg36]

I have a mishimoto all aluminum radiator, Hasnt given me any grief and its been installed for a few thousand miles. Quite cheap, good welds, only issue was fitting the hoses on the drivers side but once installed looks quite nice.

overall construction was pretty good.

[cornflakecwl]

Do you have a part number or price?

[moroza]

I bet you can use the E36 M3 radiator, possibly with minor modifications to hoses and mounting. See my thread about M60's using it.



This is what I have been told to use:
http://www.zionsvilleautosport.com/store/screen/prod/store_code/6134/product_code/E34V8AR.htm

Can you tell me who told you that, so I can go laugh in their face (or politely let them know of a solution that costs less than half that)? $564 :rofl

[cornflakecwl]

I bet you can use the E36 M3 radiator, possibly with minor modifications to hoses and mounting. See my thread about M60's using it.



Can you tell me who told you that, so I can go laugh in their face (or politely let them know of a solution that costs less than half that)? $564 :rofl

So the alum m3 is around 275? If that will work, that is definately the way I want to go. Guess I have to figure out the rad hose situation. Has anyone done this and knows a part number that can be made to fit?

Sent from my X10a using Tapatalk

[Melchoir]

OK, so I'm on my way to the gym, looking for a parking spot, in a good mood, car is driving nice, the guibo/mount and fresh oil change yesterday. COme to a light all of the sudden see white smoke all around me, shit downtown Toronto, nowhwere to stop. Finally get turned around to stop and look, rad hose off, the plastic on the rad that the hose goes onto snapped. UNdo the hose clamp, tighten it on what is left, luckily I had some coolant in the trunk, fill it up as best I can, make it home stoping twice for 10 minutes to shut it off and let it cool. Now with no coolant the highest the temp gauge got was about the 3/4 mark. I am hoping I didn't warp the head? Car is gonna have to sit for a few weeks until it gets warm enought to change the rad and hoses myself cause I am NOT paying someone else to do it. So what GOOD aluminum rads are there out there for m50 e34? If I am gonna do it, rather do it right once as this car will eventually be getting m52/s52 cams and probably FI. Suggestions please!!

And so much for my clean ENGINE!!! GRRRRR!!!!!

(This is a long story but was honestly a great experience for learning just how well BMW build their engines. For reference before people give me crap, this was on a 500$ "barn find" e36, not a pristine car and it was on the very first trip driving it home)



Just to help take away some worry in my experiences M50s really don't mind a little heat. I once had a coolant overflow crack and started venting my coolant out. I was on a very long very busy bridge when it happened, could not stop but intially it was staying a few ticks off the red zone. I had a really long section where I killed the engine and coasted with the key in on that helped bring the temp down for the rest of this bridge - but once I was over it, I was in farmland. No gas stations, no houses, nothing. Thankfully I had brought some water with me but I didn't think I woudl need to cary 12 L of it, so the 4 L i had didn't last long with it constantly being spat out of this pressure crack.

So had to drive it 20km's before I could get more water into it. Not long into the drive the car was pegged into red, with warning lights for damn near everything. Please let me restate I don't do this to cars, this was literally an "Im in the middle of no where/if this dies on me i'm fucked/no cell reception" moment and was a 500$ car, and the engine actually had a miss when I bought it(turned out to be a bad coil boot, 6$ to fix but thats another story...) I would shut it down every few K but it was losing water so I didn't dare wait to long or I would be stranded.

Finally I get into town and a block from the first service station it shut off. I thought well shit it had siezed. I put it in neutral and rolled it down to the water spout at the station, let it cool for a while and refilled it. Restarted it after it was full and it was spitting coolant out everywhere. From past experience this meant it was compresing the coolant and the headgasket/head were warped, but the tempurature was actually staying stable as long as I kept water in it.So I bought 2 flats of bottled water (car drank expensive french water on the way home... damn euros!) and made it home. Car had zero power, died a few times and at one point took almost 2 minutes of cranking to fire over again. At this point i'm just trying to get the body home, engine be damned. (It was a clean body with an OEM M3 kit, mirrors and all for 500$)

But I had already bought parts to repair the cooling system before picking up the car so I changed the overflow, flushed the cooling system and took it out for a drive. I owned that car as a daily driver for a year and not once did it ever act up again.

Here is the best part: Before I picked up the car I took compression readings and it was something like 190-180-190-170-170, the last two were a bit low.
Then that same weekend, after overheating it so bad that it shut off and driving it a good 10 minutes while in the red I took another test assuming I would be replacing an engine... Compression?
215-220-230-220-220-220.

It was the most surreal moment I've ever had. I took the readings 6 times to make sure I wasn't crazy/doing it wrong. Overheating that m50 actually improved the seal the head had after sitting for 2 years in a garage. To this day BMW engines will always have my respect for that reason.

So in short, going to 3/4 of the gauge is nothing for one of these engines.

[RobertV1]

I bet you can use the E36 M3 radiator, possibly with minor modifications to hoses and mounting. See my thread about M60's using it.



Can you tell me who told you that, so I can go laugh in their face (or politely let them know of a solution that costs less than half that)? $564 :rofl

Mike Miller BMW CCA Roundel Magazine Technical Editor was the first one who I heard it from and others who race their e34. I'm sure there are many great options for much less.

[cornflakecwl]

It does help, thanks! Gonna do the repair in my parking garage. Only thing I cant do tgere is a flush.

[Binjammin]

(This is a long story but was honestly a great experience for learning just how well BMW build their engines. For reference before people give me crap, this was on a 500$ "barn find" e36, not a pristine car and it was on the very first trip driving it home)



Just to help take away some worry in my experiences M50s really don't mind a little heat. I once had a coolant overflow crack and started venting my coolant out. I was on a very long very busy bridge when it happened, could not stop but intially it was staying a few ticks off the red zone. I had a really long section where I killed the engine and coasted with the key in on that helped bring the temp down for the rest of this bridge - but once I was over it, I was in farmland. No gas stations, no houses, nothing. Thankfully I had brought some water with me but I didn't think I woudl need to cary 12 L of it, so the 4 L i had didn't last long with it constantly being spat out of this pressure crack.

So had to drive it 20km's before I could get more water into it. Not long into the drive the car was pegged into red, with warning lights for damn near everything. Please let me restate I don't do this to cars, this was literally an "Im in the middle of no where/if this dies on me i'm fucked/no cell reception" moment and was a 500$ car, and the engine actually had a miss when I bought it(turned out to be a bad coil boot, 6$ to fix but thats another story...) I would shut it down every few K but it was losing water so I didn't dare wait to long or I would be stranded.

Finally I get into town and a block from the first service station it shut off. I thought well shit it had siezed. I put it in neutral and rolled it down to the water spout at the station, let it cool for a while and refilled it. Restarted it after it was full and it was spitting coolant out everywhere. From past experience this meant it was compresing the coolant and the headgasket/head were warped, but the tempurature was actually staying stable as long as I kept water in it.So I bought 2 flats of bottled water (car drank expensive french water on the way home... damn euros!) and made it home. Car had zero power, died a few times and at one point took almost 2 minutes of cranking to fire over again. At this point i'm just trying to get the body home, engine be damned. (It was a clean body with an OEM M3 kit, mirrors and all for 500$)

But I had already bought parts to repair the cooling system before picking up the car so I changed the overflow, flushed the cooling system and took it out for a drive. I owned that car as a daily driver for a year and not once did it ever act up again.

Here is the best part: Before I picked up the car I took compression readings and it was something like 190-180-190-170-170, the last two were a bit low.
Then that same weekend, after overheating it so bad that it shut off and driving it a good 10 minutes while in the red I took another test assuming I would be replacing an engine... Compression?
215-220-230-220-220-220.

It was the most surreal moment I've ever had. I took the readings 6 times to make sure I wasn't crazy/doing it wrong. Overheating that m50 actually improved the seal the head had after sitting for 2 years in a garage. To this day BMW engines will always have my respect for that reason.

So in short, going to 3/4 of the gauge is nothing for one of these engines.

Your compression numbers went up because you'd been driving it and had more oil on the rings. The fact that you didn't blow either your engine or at the very least your head gasket is not a tribute to bmw's build quality, but is a flat out miracle. The fact is that straight six heads are very long and are susceptible to overheating and blowing head gaskets. Having air in the cooling system can give you inaccurate readings of 3/4 temp while having local hot spots inside the head due to inadequate cooling.

BTW the bubbling of the water when you were pouring it in wasn't from compression, it's because you removed the radiator cap and the engine was hot. The cap keeps pressure on the system, which raises the boiling point. When you take the cap off it's back to 212f for water. The car's well over 212f temp, pouring water in makes it boil.

OP, keep an eye on things, if you see anything out of the ordinary keep on top of it.

[cornflakecwl]

Thanks Bin, I'm hoping I will be ok. I actually was wondering why the check control didn't report the low coolant. It seems to report these things when the car gets shut off and when I start it again nothing, or if it happens when running, it doesn't report. Is this a problem, or is it just the way it works? Seems kinda useless to me that it didn't report after my hose popped off and everything drained out!

OK so looked up the mishimoto M3 rad, good looking piece, price is right. How much work is required to make that fit in an e34? Is it just a matter of finding some hoses that will fit?

[Melchoir]

Your compression numbers went up because you'd been driving it and had more oil on the rings. The fact that you didn't blow either your engine or at the very least your head gasket is not a tribute to bmw's build quality, but is a flat out miracle. The fact is that straight six heads are very long and are susceptible to overheating and blowing head gaskets. Having air in the cooling system can give you inaccurate readings of 3/4 temp while having local hot spots inside the head due to inadequate cooling.

BTW the bubbling of the water when you were pouring it in wasn't from compression, it's because you removed the radiator cap and the engine was hot. The cap keeps pressure on the system, which raises the boiling point. When you take the cap off it's back to 212f for water. The car's well over 212f temp, pouring water in makes it boil.

OP, keep an eye on things, if you see anything out of the ordinary keep on top of it.


It was a miracle indeed - that said the previous compression numbers were taken after a test drive, so it had been lubed. My theory was the massive heat and then cooling off may have caused the rings to snug back up to the walls. When I said spitting out coolant I was being vague - I didn't mean right when it was opened or even while refilling it as at those points I expect it to spit water back at me as the cold fluid finds hot spots in the cooling channels. I mean 15 minutes after being filled/bled if the cap was off it would spit out a little spigot of water with a very constant rhythmic pulse.

Either way I have seen a lot of engines die under heat like that and the simple fact is that one did not.

OP: It may not have reported low coolant because your float could be stuck - really common. It's just a plastic donut that slides up and down a shaft in your overflow reservoir tank. May want to take it out and clean it when you do your rad, usually just needs a good scrub with soap and water to remove the random gunk that coats it after years of sitting in there.

[cornflakecwl]

It was a miracle indeed - that said the previous compression numbers were taken after a test drive, so it had been lubed. My theory was the massive heat and then cooling off may have caused the rings to snug back up to the walls. When I said spitting out coolant I was being vague - I didn't mean right when it was opened or even while refilling it as at those points I expect it to spit water back at me as the cold fluid finds hot spots in the cooling channels. I mean 15 minutes after being filled/bled if the cap was off it would spit out a little spigot of water with a very constant rhythmic pulse.

Either way I have seen a lot of engines die under heat like that and the simple fact is that one did not.

OP: It may not have reported low coolant because your float could be stuck - really common. It's just a plastic donut that slides up and down a shaft in your overflow reservoir tank. May want to take it out and clean it when you do your rad, usually just needs a good scrub with soap and water to remove the random gunk that coats it after years of sitting in there.

I just read a few posts about that. If I order a rad WITH the overflow tank will it include a new level sensor, guessing not and I will clean the old one when I install it in the new rad.

[Melchoir]

I just read a few posts about that. If I order a rad WITH the overflow tank will it include a new level sensor, guessing not and I will clean the old one when I install it in the new rad.

Its dead simple to clean once you have the tank off, just need to wipe it off and it cleans right up.

[cornflakecwl]

Any word on the thermostat? Should I be going 88 or 92 degree? What's the benefit of lower or higher temperature?

[sfgearhead]

In Canada I'd go with the higher temp. In Arizona I'd recommend the lower temp. But in a functioning system 4 degrees shouldn't matter that much.

[AZDinanE34]

Ive wondered the same thing regarding alum. radiators and ones that fit the M50. I have had the same situation years ago were I was driving to work and sitting at a light could smell coolant, pulled over and found my upper hose disconnected b/c of the plastic neck broken off and had to purchase a new radiator. The stock one lasted 12years (cracked and leaked), my second lasted 6years (tank gaskets leaked & broken neck) and now Im on my third, all Behr units…the AZ temps don’t help either but my cooling system is very important.

[cornflakecwl]

Ive wondered the same thing regarding alum. radiators and ones that fit the M50. I have had the same situation years ago were I was driving to work and sitting at a light could smell coolant, pulled over and found my upper hose disconnected b/c of the plastic neck broken off and had to purchase a new radiator. The stock one lasted 12years (cracked and leaked), my second lasted 6years (tank gaskets leaked & broken neck) and now Im on my third, all Behr units…the AZ temps don’t help either but my cooling system is very important.

Well I am probably going to go with the M3 unit once i figure out what hoses will work with it. I'll keep you posted.

[GumbysE34]

^ definitely keep us posted, as your original post exactly describes my situation on Sunday. This is the 2nd time it's happened to me (the first, about a month ago is when the neck originally broke on me; I clamped the hose to the remaining neck.)

Now my thermostat is shot due to overheating (hit the red twice for less than about 2 minutes combined total) while I was limping it to the nearest gas station. Thermostat won't open and allow coolant into the engine for refilling/bleeding.

Bought my new gaskets, coolant and thermostat, just waiting for warmer nighttime temps to change the parts after work this week.

[DrJomamachubby]

Very glad to hear that, I figured I was ok, thanks Gents. Just putting price list together, should I be going for 88 or 92 degree thermostat? Live in Canada, cold winter, moderately hot summer. I am thinking 92 is prob better?

92, 92 or perhaps in a pinch 92 - there's no good reason to go colder on any FI engine.

[motohunter4]

I've heard that cooler thermostats help. (although if I were in Canada like you, heat would be top priority)

[cornflakecwl]

92, 92 or perhaps in a pinch 92 - there's no good reason to go colder on any FI engine.
I am assuming FI in this case = Fuel Injected not Forced Induction which I do not yet have.

[DrJomamachubby]

I am assuming FI in this case = Fuel Injected not Forced Induction which I do not yet have.

right, fuel injection not carb - it's not the temp that makes cooling systems go boom it's that crazy 29 PSI cap but you never hear anyone ask "can I get a 1 bar radiator cap"

[cornflakecwl]

So I think I am gonna grab the rad out of the 328 that is at the wreckers this weekend to see how close it is to the 525 rad before I order the M3 Aluminum rad. Figure the rad will be prob $20 at the wreckers, and I can compare the two to see what I need BEFORE i order the aluminum one and possibly save myself some greif.

[rotaryboots]

I've got a Behr rad in my car. Looks to be mostly aluminum. PO replaced it before I bought the car.
Head gaskets do fail on the M50's but lucky for you, it takes just an hour to have the head off, then send it in to get surfaced and pressure tested, throw a new gasket on there, the head, and hour later, fixed for probably as long as you'll ever own the car. And its a great time to really deep clean the engine.
Call me crazy, but its not uncommon for me to do a quick wipe of my engine with 409 durring the summer to get the dust off it. I get comments on how clean I keep the M50. :) Once its clean its easy to keep it that way, or find leaks and what not. Makes it a little more pleasant to work on. I hate working on dirty engines.

Anyways, pick up a thermostat and a good water pump while you're in there...if things end up that way. I'm hoping you didn't pop the head gasket.

[cornflakecwl]

I've got a Behr rad in my car. Looks to be mostly aluminum. PO replaced it before I bought the car.
Head gaskets do fail on the M50's but lucky for you, it takes just an hour to have the head off, then send it in to get surfaced and pressure tested, throw a new gasket on there, the head, and hour later, fixed for probably as long as you'll ever own the car. And its a great time to really deep clean the engine.
Call me crazy, but its not uncommon for me to do a quick wipe of my engine with 409 durring the summer to get the dust off it. I get comments on how clean I keep the M50. :) Once its clean its easy to keep it that way, or find leaks and what not. Makes it a little more pleasant to work on. I hate working on dirty engines.

Anyways, pick up a thermostat and a good water pump while you're in there...if things end up that way. I'm hoping you didn't pop the head gasket.

Most rads are at least partly aluminum, I am talking about a 100% aluminum rad to eliminate the problems with the oem where there is still plastic. My engine was spotless before this happened, trust me there's a thread to prove it. I will be changing all hoses, water pump, t-stat and possibly fan clutch when I do the work.