forgot to tell us if it overheated. if it didn't, maybe it's fine.

 

it did

 

You should not be removing the tank cap when it is hot. If you have to drive to a safe point, so be it. In your case, these motors do not like overheating. Cooling systems need regular maintenance.

 

Was it 2km or 5km? Not sure why you HAD to drive it that far to meet a tow truck.

we can’t tell from your post. Replace the hose, fill and bleed it properly and begin driving it, getting it up to operating temps, and looking for overheats and other symptoms of a warped head.

I would drive initially with accurate coolant temp displayed in the display..the temp gauge is nearly useless.

 

Ahhh, head gasket roulette.

Fix it and find out!

And 'filling' it without bleeding isn't much help in circumstances like this.

t

 

OP how fast were you going? Were you going faster than 55mph? Based upon your description it seems like you stopped to fill with coolant when the engine was hot and then drove 2km further to a parking lot. I can only assume it wasn't safe to stay where you filled the coolant for an extended period of time. If that wasn't the case, next time stay and use hazard lights also good to have a triangle, road flares, and duct tape (never know if you can MacGyver it). But the system needs to be bled properly and it doesn't sound like that was done during the fill. Anyway, I'm not certain based upon your description. It doesn't sound promising though. As mentioned above replace the hose, fill with coolant, and bleed the system properly. I hope you get lucky.

 

Not sounding good toyota time

 

If anyone who's unaware of what goes on in an internal combustion engine ever runs across this thread in the future, let me add something useful for all time. For that "ring of authority", I am the former Worldwide Powertrain Planner for General Motors back when they were the largest automaker on earth.

A running engine's insides are constant explosions. Every second of every day you are operating it, the engine is trying to kill itself by melting valves, frying oil, and warping parts. You could almost say that's its job - trying to destroy itself, which it can do in about a minute flat. Since it's a mechanical thing, it doesn't care about your feelings, or that you've been saving up to start college, or for that coveted trip to Europe. All it wants to do is overheat and destroy itself - every time you turn the key.

The only thing that keeps this from happening is the cooling system, which is a fast moving river of water through the engine that sucks heat off the engine as fast as the engine generates it. This real time battle is going on at all times, whether you are headed to the gym, or commuting to work. The cooling system is your friend and stands between you and $6000 worth of damage. So if you operate your engine without a completely full and operating cooling system, you are just 90 seconds or so from that $6000 check.

I want you to know this so you don't mistakenly think the cooling system is "just another system on the car", or merely a convenience you can get around to maintaining or fixing at your leisure. Too many people do not understand this relationship, and now the OP is about to find out if their decision to ignore a stressed cooling system to move the car for a low level reason (compared to the risk) is going to cost them big bucks. Folks, don't do that. If you have a headlight out, drive home. If your window won't roll up, drive home. If the heater fan makes noise, or the fuel pump is making noise, sure - drive it home. But if you are low on coolant and/or it's leaking - don't start an inferno in your engine that cannot be controlled.

 

Your M54 will not like being overheated like you did. Fix all of the outside stuff, belts and hoses, and refill and bleed, and watch it for a while.

My M50 had a similar problem (blown hose), and I fixed the hose and did some other related service, and drove the car for several months at 120 miles per day 5 days a week. I noticed a very slight rate of consumption of the coolant -- maybe half of the expansion tank in 3 weeks -- but no overheating or anything like that. Then one day I went out to start the car for the trip to work, and the engine hydrolocked. I pulled all 6 plugs and turned the engine over by the bolt on the front of the crank, fluid came out of the #3 Cylinder. I had AAA take the car into town to the mechanic for a head gasket. He said that the gasket was not damaged, so I started looking for other things and found a reference to cracked heads. There was a guy out of Sacramento that fixed the crack so I bought a head from him.

My point is, you will have to pull the head to see, and you should not just replace the head gasket without looking closely at the head for cracks. There is a water passage next to an exhaust valve, the wall separating the two will have a crack that allows coolant to seep directly into the exhaust stream, the seepage will be very slow and this is why it took me several months to see it.

 

You can Google, BMW M54 CRACKED HEAD, then look at the Images to see where you need to inspect your head. I would cross my fingers in hopes that I did not crack the head, but this might just be wishful thinking.

 

First fix your current issue, so it doesn't leak coolant anymore. After that you have to figure out over time if your engine has been damaged or not. Hopefully not, but only time will tell. There is not reason to disassemble the engine right now, while there maybe is no damage at all.

 

Agree. Fix the leak. Fill and properly bleed it with fresh coolant. Drive it and watch the coolant level like a hawk.

 

Hey everyone. My cars coolant line bursted mid drive and i had to drive from that spot to a parking lot about 2km away in order to get towed home.

Sorry, head will need to be out. I think the head bolts also pulled the block threaded holes too. TimeSert time.

 

Our Man Sapote: The M54 head gasket whisperer. Even over the internets.

t

 

So little update, I pulled everything apart today to find a leak and realized one of my hoses wasn’t fully on, so i fully put it on, put everything back together, topped up coolant and bled system and started the car to see if the leak was gone. It was not leaking coolant when car wasn’t on. And now it wasn’t leaking when it was on either. However, i was blowing white for a minute when i revved the car. So i turned it off and thought it was my head gasket and called it a day. But my oil was not and still is not milky. I just turned my car back on and gave it a few revs, no white smoke or anything anymore. No weird noises. Took it for a drive around the block and the temp stayed where it was supposed to be with no performance issues or anything. So now i’m just confused about what the fuck is going on. Obviously i’m not going to drive it anywhere more until i figure it out for sure. The heat definitely messed something up, but i’m second guessing my headgasket call. Any ideas? Worse comes to worst i’ll sell this pos lol. Engine only has 140k kms on it but this thing just has problems after problems. Never have had a engine issue until now tho.

 

You cannot tell if the head gasket is gone using your test method. If it is gone, maybe the test will confirm, but if not then the results of the test are inconclusive at best. A cracked head, and in some cases a blown head gasket, will not result in water and oil mixing, so this conclusion does not hold up.

The head gasket and the cracked head require all of the same work, but you cannot blindly replace the gasket and think you are done. You MUST inspect for cracks because if you do not then the replacement head gasket will not work anyway. My car went for 6 months at 120 miles per day, 5 days a week, plus whatever weekend trips I made. I had no repeat overheating, none. If I didn't have a cylinder get filled with coolant that caused the car to not start -- engine hit a hard stop on the starter motor -- I would never have known I had a problem.

Never use revving a cold engine as a diagnostic. The results of this seldom will tell you anything useful. It's a far better test to drive the car around the block in a small circle, a mile or so, then come home and check stuff. Drive again for 5 miles, maybe hit 45 on the local artery roads. Come home and check stuff. Let the car cool and see if the coolant is still full, top as needed because you might not have gotten it full anyway. Take the car on a longer trip, 10 or 15 miles, and see how it looks. Make a small trip at low speed so if it does not go well, you can walk home and get your brother to help you bring your car back. If the small trip goes well, make a larger trip at an intermediate speed. Then make a short trip on the freeway, an exit or two one way and then come back. You make a slow speed trip, then a faster trip, then a full on freeway trip. This is a far better test procedure than revving to redline in your driveway.

 

^hairline crack allowed coolant to seep through the cylinders which possibly sealed a bit after it warmed up. just guessing though

 

Purely circumstantial and your mileage may vary, but I drove home (yes stupidly) about 5 miles with a gaping hole in my radiator in my 330 once. It started overheating about a mile from the house but I still limped her home. That was 30k miles ago and the head gasket and block were both fine… just needed a new rad and hoses so I hope you have the same result

 

Similar happened to me in my M54B30 E39 some years ago. Hairline crack in plastic hose connector on the radiator caused coolant loss. Wife was driving and didn't notice the temp gauge. We were on the motorway. When the gong came on I told her to pull over to the hard shoulder immediately and cut the engine.
Breakdown man fixed the leak and filled the coolant so we could get home. Car had not lost all of its coolant though.
That was some years ago and probably about 40,000 or miles ago.
I did a full cooling system refresh since then.
Car has been fine ever since.

When people say I "had to drive the car with no coolant" unless they are happy to spend a gew thousand my view of "had to" is the absolute minimum get out of the traffic immediately to a safe place and cut the motor.

 

I'd set the float tip level with top of neck. Drive the car, monitor coolant level when cold. Nothing to lose. Don't go far from home.

 

Drive it and observe. No need to be confused, use profanity, or park it. Drive it and the car will tell you if its damaged.

 

Compression gas is much higher pressure than coolant pressure. As such, you may have better luck looking for compression gas in your coolant, rather than coolant in your oil. You can purchase compression gas tester for your coolant for like $20.

Having said that, do you know for sure the white smoke is coolant? Is it possible that your smoke is actually from oil such as a bad CCV?

 

Agree with the above (except the profanity- it's a German car, and likes to be sworn at, occasionally)

Drive it and monitor the coolant usage.
White smoke's normal on cold startup, as exhaust has a high
water vapor content. You're looking, now, because you're worried. If you want, taste it.
If it doesn't taste like anything, it's just condensation. If you have to spit it out, then yeah,
coolant.

For some reason, 3 of our cars have had coolant problems this winter.
One lit the red light- and so far, it's been fine, too.
(Farking E39's do NOT have a coolant level sensor on the 'low' spec dash-
they have a PLACE for the sensor AND light, BMW just chose not to populate them. See
above re: swearing)

t

 

Agree with the above (except the profanity- it's a German car, and likes to be sworn at, occasionally)

Drive it and monitor the coolant usage.
White smoke's normal on cold startup, as exhaust has a high
water vapor content. You're looking, now, because you're worried. If you want, taste it.
If it doesn't taste like anything, it's just condensation. If you have to spit it out, then yeah,
coolant.

For some reason, 3 of our cars have had coolant problems this winter.
One lit the red light- and so far, it's been fine, too.
(Farking E39's do NOT have a coolant level sensor on the 'low' spec dash-
they have a PLACE for the sensor AND light, BMW just chose not to populate them. See
above re: swearing)

t

Yes that was the damn problem I had. When I did the refresh I bought a sensor as realoem seemed to think it had one buy

Does the E39 have the audible warning when overheated? Was the red dot on the temp gauge turned ON?
I don't think the E46 stock setup has any audible warning.

This was a long time ago so I may be mistaken. Maybe it was the red light rather than the gong that woke up the driver.

These overheating threads seem to be coming up almost every day at the moment.

Having refreshed the cooling systems on both my cars (bar the hard pipes under the intake manifold I now know in hindsight I should have probably should have done) I am now considering reprogramming the temperature gauges to give earlier warning and have less dead band at 12 o'clock.

 

So i’ve already made a post about how my coolant completely disappeared 2 nights ago and my engine overheated and i had to get my car towed home. Now i have my car in pieces in my garage prepared to replace the head gasket but now that i’m thinking more about it besides the white smoke there is no other signs of it being the gasket. Oil isn’t milky, Coolant does not look milky or look like it’s bubbling as soon as i start the car. So i’m kinda stuck. I’m 95% sure the reason for the coolant loss was my water pump failing (which would make sense because the stock water pump has 140k kms on it). Someone said in my last thread that it could be a hairline fracture? What do you guys think? And how should i go about fixing this? I’m a pretty handy guy and have worked on my car since i’ve owned it with no issues from my work. Should i start with replacing the water pump? Thanks

 

If it was me I'd go to Harbor Freight and buy a combustion leak detector kit. I think they run like $25 its a pretty simple go or no go test. Then you'll know for sure if you blew a head gasket.

Just my 2 cents,

Poon

 

If the pump was the leak, then yes replace that, confirm no leak and drive n monitor.

 

I fitted my car with an audible alarm from china as a backup even though i have had a full new cooling system.

 

Hey, it's your time and your money, but why are you rejecting advice to drive and monitor? Or do some tests?