'94 Boid: Mystery coolant leak

Re: '94 Boid: Mystery coolant leak

LX V8 (4.6L), 61k mi.

Some time ago, I spot a puddle of coolant dripped from the plastic pan/cover under the radiator. Has recurred several times. Drips from the pan to the left of center of motor when facing front of car. The left 2+ feet of the inside of the pan is wet.

The ice finally melted, I get a chance to crawl around on the conny-crete to see if I can find the source of the leak. Coolant reservoir is about a pint lo.

The upper hose is fine. There is no evidence of coolant under the weep hole in the water pump. It's a bitch to get to, but I'm 90+% sure the lower hose is not leaking. It's way over on the right anyway, and I didn't see any coolant in the pan under the hose.

So I'm shuffling thru my silly goose Haynes manual, trying to find what else to check. What I see under the hood, of course, doesn't much match what I see in the manual. Visability around the bottom of the radiator is kinda like trying to see whilst immersed in a cauldron of india ink.

It's gotta 4r70w tranny. Are there lines to the rad. to cool the fluid?

Any other ideas about where to check for a leak?

TIA, Puddin'

Reply to
Puddin' Man
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Yes, there are lines to cool the transmission fluid. But they don't carry coolant - the transmission fluid circulates through a compartment in the radiator. It's not that unusual to have a leak in a 12 year old radiator. A pressure test will probably solve the mystery, one way or another. Quick and easy for any radiator shop to do. Or rent the hand pump and do it yourself.

Reply to
Happy Traveler

I can think of two potential issues. Are you only seeing this problem since the weather has turned cold ? Years ago there was a problem noted on explorers where the rubber seal between the plastic tanks and the radiator core would shrink with the cold weather causing a leakage problem.

Second thought, I hear the 4.6 has a rubber hose under the intake going to the back of the water pump. Maybe it is getting tired.

Reply to
Steve Stone

Not just explorers, either... pretty common complaint on here a year or so ago.

That's where I would look to start with.

Reply to
Backyard Mechanic

Looks that way. Had nary a problem with cooling system until about a month ago.

Well, I did. All I see is hoses and clamps. The top rad. hose is 'return', the lo 'supply'? The lower hose runs from bottom of rad. to motor with a 'T' that branches to the plastic tank. No coolant under the tank clamp. Tiny bit of coolant on pan under the clamp on bottom of rad. (most is on other end of 3' wide pan). I can just get a finger or 2 on the bottom of the juncture of the hose/rad.: finger comes back dry.

manifold?

The back of the water pump on my 4.6 mounts flush against the block, near as I can tell. Can see no hose under the intake manifold.

To further confound matters, the leak appears to be intermittent. I added maybe 12 oz water to bring it up to level, expected it to drop. Put 30 mi. on it, couldn't spot a leak. Just put another 20 on it, coolant is still up to level.

"Mysteries Abound!"

Thanks, Puddin'

Reply to
Puddin' Man

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