Blown Headgasket???

[athflying79]

I was driving home and got a dong. Looked and the "Coolant Temp" warning was staring at me. Turned the car off imediately and popped the hood. Popped the bleeder screw to see if it was possibly just some air in the system. I did get some air then coolant came gushing. Re-started and the temps went down, heater was blowing warm, and the pisser line was pissing. Figured it just happened to be an air pocket from changing hoses awhile back. Made it almost 25 miles without anymore problems then as I pull into my neighborhood I see the temp needle climbing. I immediately shut the engine off and coast into the median. I again popped the bleeder, but no air. I hear some hissing from underneath and look to see coolant dripping on the exhaust. At this point it was actually gushing pretty good. It seemed to be coming from the rear of the engine directly underneath the reservoir. I couldn't actually see the coolant gushing from the head nor could I find a hose that may have burst. I figured the damage was done and drive another two minutes to get the car in my driveway and it actually didn't overheat at this point. Once in the driveway I hear more hissing. I climbed under the car avoiding the extremely hot coolant but still can't find the source. I do however hear what sounds like steam escaping. It was dark by then and couldn't see a thing. I can only guess the HG went although I'm praying for a ruptured hose. I recently replaced all the coolant hoses, so I'm not extremely hopeful.

I love this car, but I just don't have the time to put into it that it needs. It's kind of like that cute puppy that constantly destroys the house. You love it to death, but you just can't deal with the daily headaches. I just don't have the time to do a HG and can't fathom paying $1,500+ to have someone do it and not know if it was done correctly.

Any thoughts are appreciated.

[Blitzkrieg Bob]

and it is just a heater hose

[Martin in Bellevue]

You could get a chemical test kit to check for combustion waste in the coolant. You could also pull the spark plugs & check for 1 that was steam-cleaned, indicating headgasket failure.
A headgasket job could be completed in a Saturday, if you didn't want to have the head freshened up by the machinist.

[joshua43214]

many times I have seen small pin holes on hoses that spray and almost invisible stream of hot coolant across long distances, then drip down making things like firewalls,engine blocks, headlights etc appear to have a coolant leak. In the driveway with a watchful eye on the temp gauge, heat the car up until it starts spraying again. use an index card or similar and move it about the hoses or near where the leak apears to be coming from.

Unfortunately, if the head gasket is leaking outside the car, it is probably age related and the head will most likely be pitted. Check the oil for coolant or pull the plugs and look for a very clean plug, but just because the coolant is leaking to the outside, it doesn't mean its leaking to the inside. Use a dentists mirror and check all along the head gasket seam, you should be able to see any leakage.

Any shop that works on alot of BMW's will have the proper adaptor for pressure testing, might be worth a few bucks to have it properly tested.

As a side note, I knew a tech that had a car that leaked coolant to the outside but not the inside of the engine, he poped the valve cover off and retorqued the head bolts figuring to do the job when he had time. He drove the car for another 20k miles before he traded it in.

[gmannino]

There are a few coolant hoses on the rear of the engine. Those would be the first things I would check.

[athflying79]

I'm going to check the hoses this weekend...the more I think about it, the way it was gushing it only makes sense that it was a hose. I think what I'm going to do is drop my insurance on the car, pull her in the garage, and work on her when I have time. In the meantime it looks like I'll be buying something cheap, good on gas, and maintenance free (other than oil changes).

I work to much as it is and am actually just starting to go back to school so I need a car that is dependable and not waiting on me to do something to it all the time. I do love it and enjoy working on it, but I just haven't got it to where it is reliable as a DD.

[mamilapon]

I don't think its the HG (specially if you have good quality coolant in it, and changed it every two years. I would suggest you top the coolant up, take it for a drive until it gets to operating temp. Stop, shut down and have a good look under the hood with a good source of light and an inspection mirror. As mentioned earlier it could just be a leaking hose..good luck!

[athflying79]

All the coolant hoses are less than two months old. I did a preliminary check and none of the hoses came off, so hoping I got a bad hose and it split somewhere.

[632 Regal]

after I replaced all my hoses, one of them hard to get at ones had a leak at the clamp, I checked and ALL the clamps needed to be retightened...hopefully this is the case with yours too.

[athflying79]

I finally calmed down to where I could work on her without being tempted to throw a ratchet through the windshield.

I put her up on ramps and looked for traces of dried coolant and found nothing. Then I topped off the coolant with the bleed screw open and I actually didn't lose as much as I thought...less than a gallon. Fired her up and it ran for over ten minutes in the driveway without a hiccup. The heat was blowing hot, pisser line was pissing, and never got any air out of the bleeder. Turned the heat off for about five minutes and never went past 12 o'clock on the temp gauge. Crawled underneath with a halogen light and could find no leaks as she ran. I traced as many of the coolant hoses as I could to check for broken or leaking hoses and found none.

At Jeff's suggestion, I'm going to re-tighten all the hose clamps. My theory is this......the day it overheated it was running low on coolant because of my recently changing the water pump and the system must of still had a bit of air. I saw it was a tad low, but didn't have coolant with me and figured I could make it home no problem. Then it started to overheat. At this point I parked and walked to get some coolant (type and brand are unimportant). The car was still very hot by the time I got back. I topped off the reservoir, bled, and then drove home. Everything was fine until I pulled into my neighborhood and not only did it overheat, but leaked a little less than a gallon of coolant all over. I think maybe because I filled and bled while it was so hot that I overfilled the system (is this even possible?? I only think so because the coolant level line states for "cold" or "kalt".) Then as I pulled into my neighborhood the system momentarily was air-locked which caused an excessive amount of pressure. At this point somewhere a hose clamp let coolant and steam escape rather than the reservoir top.

Now that the pressure levels have subsided, the system is working properly, but still have a slightly loose clamp somewhere.

I will take her out for a short drive close to home in the next couple days and see how it goes.

[genphreak]

The problem sounds like the classic tough-bleed. Did you drill a 1/8" or 2mm hole at 12 O'clock in the thermostat? Read up on that if not. One does not really need to, but it makes bleeding simpler. If you don't, the bleed you carry out must be by the book to prevent airlocks...

Also be careful tightening clamps, you can overtighten the radiator hoses if the radiator is old and brittle- the plastic tanks and necks just go crack once the car heats up if you go too tight. Same goes for the heater valve body and overflow tank connections. With newish (good) hoses and clean connections one needn't tighten too much.

Oh and you are using Cool-blue BMW coolant right? JIC u don't know; it won't affect overheating, but you don't want anything else in there, a lot of coolants are highly caustic on the internal components, I run plain water until I know the cooling system is sealed and working (a day or two) then I drain and replace with cool-blue at 1:3. :) nick

[632 Regal]

agreed that it's a real bitch to bleed, any air can cause an oveflow as the air expands. You cant overfill but you are experiencing an air pocket somewhere in your system.


The problem sounds like the classic tough-bleed. Did you drill a 1/8" or 2mm hole at 12 O'clock in the thermostat? Read up on that if not. One does not really need to, but it makes bleeding simpler. If you don't, the bleed you carry out must be by the book to prevent airlocks...

Also be careful tightening clamps, you can overtighten the radiator hoses if the radiator is old and brittle- the plastic tanks and necks just go crack once the car heats up if you go too tight. Same goes for the heater valve body and overflow tank connections. With newish (good) hoses and clean connections one needn't tighten too much.

Oh and you are using Cool-blue BMW coolant right? JIC u don't know; it won't affect overheating, but you don't want anything else in there, a lot of coolants are highly caustic on the internal components, I run plain water until I know the cooling system is sealed and working (a day or two) then I drain and replace with cool-blue at 1:3. :) nick