Alright, so i got this automatic 1986 240 DL Wagon named Mulva, she's always givin me a new job to do over the weekend with her. But i don't like her new trick she's playin on me. Everytime i go somewhere i have to fill up the coolant reservoir with water - she then runs fine without overheating. When i go to leave wherever it is i'm going, it's allll gone. I've seen no leaks, so i'm looking today hard and hoping it's just a loose hose, or leak from somewhere. I replaced the water pump and radiator hoses about three weeks ago. She was running perfectly. Here's a prelude to the mystery though. I noticed that when i had done sustained driving over 70 mph, when i arrived home, the coolant level in the reservoir was lower than when i started and there were obvious signs that it had leaked out of the reservoir. The cap still holds pressure cause every time i take it off it goes psssssshhhhhhhh real loud. But maybe under driving conditions it's even stronger. Could this be it!? please tell me it's not the head gasket, please! ahahaha.... any help is appreciated. Thanks fellas!

-jg OUT!

Time for a new head gasket (boooooooo! thumbs down!). How long does this take? I have no choice but to do it myself since i have no money whatsoever.

-jg OUT!

Borrow a compression gauge from someone and do a compression test. That'll at least give you a better idea as to whether the head gasket is the real cuplrit. I'm not sure what else it could be, though.... heater hose leak, perhaps? That's about the only other place that coolant goes.

There are some "freeze plugs" on the engine in places where leaks are not obvious, but you can usually see/smell steam and antifreeze right after you stop.

The fact that it appears that it is forcing fluid out of the reservoir when you are running, but the reservoir seems tight after you stop, definitely sounds like a head gasket leak.

It should not be difficult or expensive, but you will definitely kill a whole Saturday if you've not done it before. Get fresh intake and exhaust manifold gaskets while you are at it. If you don't own a torque wrench, borrow one.

It would be prudent to get a straight edge (straight to within a couple of thousandths of an inch over 3 feet, not a yardstick) and check to see that your head and deck are flat while you have it apart. They probably are flat, but if they are not and you don't get the warped surface machined, you'll be doing another head gasket job in a few weeks.

AHHH! I asked myself that question about two weeks ago in my Chevy. Huh, says me, no sign of external leaks. The problem was alleviated some by running the a/c so the fan stayed on. $5 replaced the thermostat and it ran great for two or three days, then it stalled out and upon inspecting it I discovered where the coolant had been going - through head gasket into block. No good. Car gone - the repair would cost more than the car's worth. A hard lesson learned, and now I'm reviving the 240.

Coolant can't go many places. Check first for any external leaks.

Look for coolant in your oil - it will be a greyish foam. Check dipstick and engine for this.

Look for oil in your coolant.

IF you find either of these two, don't drive anywhere.

Use a 50/50 mix or better of coolant AND water. Never use cold water.

So yeah, this may or may not help, but don't do what I did as it is no fun at all. (1. don't buy a chevy 2. don't buy a stinking v-6, and 3. don't blow a head gasket) Also don't listen to the radiator guy when he says "drive it around some more and see what happens..." Punk.

Good luck,

Mike