Coolant loss

[jpcavanugh]

I am losing coolant in my 93 CV LX. Here is the mystery. It does not seem to be leaking from any hoses, from radiator, from thermostat, or anywhere that I can see from the top of the engine. Once up to temp, it is dripping from the bottom of the engine behind oil pan. I have not had a chance to get the car into the air so as to crawl under and inspect. It seems to be coming from around centerline of engine at the back.

There is no gunk in the oil. Do these aluminum blocks have freeze plugs? Just a wild guess. My fears are either head gasket or intake gasket. I do not believe that it has been overheated, but I have a couple of teenagers driving the car, so anything is possible. This seems to have started about a week or so ago. Any ideas?

[BerniniCaCO3]

Is there a heater hose up there?

Best way to find out, is get under there with a powerful flashlight and just look.
Better still, maybe autozone rents a pressure tester? Make sure the coolant is full, take off the radiator cap, and put 20lbs pressure on the system. You may be able to see it actively leaking. At a minimum, you can watch just how quickly the pressure bleeds off... (in a brand new, healthy cooling system, it should hold for at least 30 minutes if not hours. Sometimes, the testing tool itself bleeds off pressure so beware of that...).

[jpc]

Do the aeros have an EGR cooler with its own miniature heater hoses? Or was that nonsense gone by 93.

[sly]

check the hose off the back side of the water pump. If that springs a leak, it'll drip off the back side of the engine. Also, that pipe goes to the heater hose... and to replace that thing, you have to take the intake off. I really f'n hate that hose. If you do have to replace it... replace the pipe with just some LONG hose all the way to the heater core and put some corrugated wire wrap around it to protect it from the engine heat.

[SVT98t]

+1 to what Slymer said. Also, you may have a blown intake manifold gasket. That happened to me. Unfortunately, all the coolant leaked into the #8 cylinder. Fail.
And the coolant EGR cooler thing was eliminated on the 4.6s.

Let us know if we can be of further assistance.

-ryan s.

[jpcavanugh]

Thanks for the ideas, guys. I gave up and took it to my mechanic. Turned out to be two leaks - hose out back of water pump and pipe under intake. I let those guys do it. Writing a check was only painful for a few minutes, while the mechanic had two miserable days.

[sly]

yes, that pipe and 3 inches of hose under the intake is a horrible design. They fixed that with the PI engines if not sooner. There's still a pipe under, but no more rubber to break IIRC.

[Lincolnmania]

theres a hose and a steel pipe under the intake manifold......that's probably your problem

[SVT98t]

I know my PI motor has a metal line running out of the pump.
Oh, I forgot to add before, these cars have iron blocks, not aluminum.
Well, it's good that it's fixed. Keep on trucking!

-ryan s.

[Chevyguy]

Only 2002 - 2005 4.6 Explorers had the Aluminum block 2V 4.6, actually saw one in the trunk of a Grand Marq in the junkyard last summer. That Aluminum block is pretty, but most of those engines get thrashed by the Soccer moms who have no clue you need to WAIT for a aluminum block engine to warm up before beating on it.