5.0 Coolant Mystery

Then it must be going out the exhaust...

Have a pressure check done on it, and how do you know the oil's just fine?

Years ago, I had a problem with my 86 v6 mustang. There was a pinhole leak in one of the heater hoses that just happened to squirt a thin stream of coolant onto the exhaust manifold. It took forever to find. When idling, it wouldn't leak at all. Even holding the throttle open wouldn't make it leak most times. But when the heater was on, and the thermostat in the right position, at the right temperature, it leaked. In my case, I could never find a puddle or anything, but could smell the vaporized coolant. But if it had dripped on the road instead, it would have been a lot harder to find.

Could it be a bad heater core?

brian

Mmmm, Not necessarily. :oP

I had the same problem with my old 72 fastback. One of the head gaskets was blown and the coolant was going out the exhaust. Look at the exhaust pipes for steam. Fred

Cracked block ? Pinhole leak in a freeze plug?

Backyard Mechanic wrote in news:Xns978E563303D06pettyfogery@207.115.17.102:

Uh, I tasted it.

Nothing in it but good ol' Mobil-1. No creamy or watery stuff. Nothing coming out the tailpipes but beatiful stereo 5.0 sound.

"brianlanning" wrote in news: snipped-for-privacy@v46g2000cwv.googlegroups.com:

Inside's dry as a bone. Original core, too. :)

No leaks around the hoses, firewall (in or out), or floorboard.

No steam, condensation, or anything else out of the ordinary. Checked it today after it was nice and warm.

"Fred V." wrote in news:QboUf.171$ snipped-for-privacy@newssvr24.news.prodigy.net:

"Michael Johnson, PE" wrote in news:lf6dnaSymafW67zZnZ2dnUVZ snipped-for-privacy@giganews.com:

Yah, that's what it's turning out to be. Can't find a damn thing wrong with it, and it runs beautifully. No telltale noise, smoke, water, anything. As soon as my son's done with school I'll take it in and have them check it out. In the meantime, we'll just keep filling it up every weekend...

It's a 5.0! No way... ;)

"KJ.Kate" wrote in news:58IUf.1397$ snipped-for-privacy@bignews1.bellsouth.net:

LOL.... uh huh... right.

What do your exhaust tips look like? Have you pulled any plugs and looked at them?

: >> Doesn't leak when the car's idling or standing still, even after 1/2 : >> hour or more. Revving it up all the while - no leaks. No puddles : >> after it's parked, nothing wet underneath. It's gotta be happening : >> only while driving, but what the heck could be the source? Water : >> pump's dry underneath, no signs of leaks or wetness anywhere near the : >> radiator. Oil's just fine, so no head gasket problems. : >>

: >> Any ideas? : >

: > It could be a number of things. As BY mentioned, it might be a : > leaking head gasket. This could show as steam exiting the exhaust but : > sometimes that isn't the case. A mechanic can check for the presence : > of hydrocarbons in your coolant and tell if combustion gases are : > leaking through the head gasket. This won't tell if the leak is : > one-way (i.e. if the coolant is leaking into the chamber). Other : > than this it would have to be leaking somewhere, somehow. It might be : > a slow leak that happens in a place that won't leave a puddle. Also, : > you might check the heater core but this usually is obvious from the : > smell of coolant and/or a steamed up windshield. My Explorer had a : > leak I couldn't find and it turned out to be a crack in a plastic : > distribution piece next to the firewall. Only after it broke : > completely did I find it. Good luck, finding a slow coolant leak can : > be a real PITA. : : Yah, that's what it's turning out to be. Can't find a damn thing wrong : with it, and it runs beautifully. No telltale noise, smoke, water, : anything. As soon as my son's done with school I'll take it in and have : them check it out. In the meantime, we'll just keep filling it up every : weekend...

I don't think it is a blown head gasket. Your engine is basically stock and the 302's rarely blow head gasket unless you give them a good reason (e.g. install a blower etc.). My guess is it has a leak that is hard to detect. Can you smell coolant in the engine bay after a good long drive?

I have used and abused my bone stock 160k mile short block in the worst way and it took it all. This included showing it 16 psi of boost. If the block is cracked Joe needs to interrogate his son. Maybe he is sneaking in some nitrous when he takes it out. :)

: >

: > LOL.... : > uh huh... right. : : I have used and abused my bone stock 160k mile short block in the worst : way and it took it all. This included showing it 16 psi of boost. If : the block is cracked Joe needs to interrogate his son. Maybe he is : sneaking in some nitrous when he takes it out. :)

Kids are like monkeys- What they don't break, they s*it on.

I know the 5.0 is tough, I've got to poke him just a little though :¬)

"Michael Johnson, PE" wrote in news: snipped-for-privacy@giganews.com:

Agreed.

Again, agreed.

Nope. Nothing. Nada. Zilch. Just like it wasn't leaking at all.

I'm thinking that it's something that only leaks under stress/pressure, like when you're driving. By the time you stop and look, whatever was leaking is all dried out due to engine heat. But there are no telltale signs of dried-up coolant, either...

"KJ.Kate" wrote in news:6YJUf.872 $ snipped-for-privacy@bignews7.bellsouth.net:

Like new. ;) Actually, they're just like they always have been. Sort of black on the inside and polished on the outside.

They're gorgeous. Used, slightly greyish-brown, but not black/wet/white/etc.

happening

"KJ.Kate" wrote in news:rbRUf.1444$ snipped-for-privacy@bignews1.bellsouth.net:

Heh. I check the tires after he gets back home. So far no telltale signs of anything out of the ordinary. And since he's set to inherit the car, he's taking pretty good care of it.

Even if he were abusing it, the tranny'd be the first thing to go, as it's the weakest link. That motor is bulletproof.

And the worse of 'em fling it at you, too! ;)