The Mystery of the Disappearing Coolant

[92E34]

As many of you know I've been fighting with my M50 to get it running after I had a timing chain tensioner give up the ghost.

Now I've replaced the all the seals, gaskets, and O-rings. But now i'm facing a new problem. I'm losing coolant. So far i've put 2.75 gallons (11 qts). But the thing is, I've got one of those fancy behr radiators that doesn't have a seperate expansion tank. Its not coming out of the tail pipe, nothing on the plugs, no foaming on the dipstick. What the heck is happening?

[632 Regal]

whats the system supposed to hold? is the heater on hot and full when you bleed? Bleed properly, make sure the piss hose is clear. good luck nighty nite time and most dont log back in til monday. Ill check back later.

[rob101]

As many of you know I've been fighting with my M50 to get it running after I had a timing chain tensioner give up the ghost.

Now I've replaced the all the seals, gaskets, and O-rings. But now i'm facing a new problem. I'm losing coolant. So far i've put 2.75 gallons (11 qts). But the thing is, I've got one of those fancy behr radiators that doesn't have a seperate expansion tank. Its not coming out of the tail pipe, nothing on the plugs, no foaming on the dipstick. What the heck is happening?

heater mate, i'd say heater

[Booster]

Underneath the plastic manifold runners was a small water hose that had a pinhole leak on my M50. It lost fluid for a few years before I took a penlight and found that sucker ! You'd have never noticed it otherwise.....except the drain on the fluid level.Never saw anything drip or leak to the ground......it was such a fine mist I believe it may have mostly evaporated during use.
Get yours hot and check under there.
Best of luck...........Vinny

[Alan_525i]

As many of you know I've been fighting with my M50 to get it running after I had a timing chain tensioner give up the ghost.

Now I've replaced the all the seals, gaskets, and O-rings. But now i'm facing a new problem. I'm losing coolant. So far i've put 2.75 gallons (11 qts). But the thing is, I've got one of those fancy behr radiators that doesn't have a seperate expansion tank. Its not coming out of the tail pipe, nothing on the plugs, no foaming on the dipstick. What the heck is happening?

FYI, my head leaked coolant into the motor for nearly 6K miles before it was noticeable in the oil, and then only when the oil was drained. You have leaked a lot more coolant than I did (maybe total was a gallon and a half or so) but keep this possibility in mind.

[SnakeyesTx]

If you bled the system properly, its supposed to hold 3 gallons of coolant/water mix. It wouldn't be going anywhere... just filling up the voids

[92E34]

Well I've put in almost 3 gallons. I put the coolant 3 notches above max cold. I just put 6 miles on it and at hot its 3 ticks above the bottom of the radiator. I opened the cap and some coolant did come out and the level went up about 3 more notches.

I'm due to take the car on a 100 mile trip tomorrow and I don't want to break down.

[92E34]

Well I ran the car around today, I put about 20 miles on it just with in town driving.

If I look on the side of the radiator (the tank side) it looks at maybe the 3rd notch up from the bottom when its running. If I shut it off it goes below the bottom notch. But When its absolutely cold, it is about 4 notches above the cold mark. I just want to make sure that its normal before I head off tomorrow.

I did run the heater tonight and I didn't get any steam out of it.

[92E34]

Well I did figure it out.

Turns out I didn't completely torque one head bolt down. I guess I skipped it when I did my last series of torque. So around the head I went and it doesn't leak now. Runs about one needle width above the middle notch.

So Newbs: Check your torque pattern. If you are worried, mark the head with numbers from a sharpie.

[genphreak]

Well I did figure it out.

Turns out I didn't completely torque one head bolt down. I guess I skipped it when I did my last series of torque. So around the head I went and it doesn't leak now. Runs about one needle width above the middle notch.

So Newbs: Check your torque pattern. If you are worried, mark the head with numbers from a sharpie.

You best change your O2 sensor now, they don't like even a whiff ethylene glycol, makes them go off, never to return. I run plain water until I know the head gasket is sealed, it takes a couple of cylces to do this. Then after the first day of driving I empty her out and change to 33%-50% cool blue and demineralised water. It is the right way to do it. No offence, but you did renew all your head bolts too right?