Puzzled about coolant loss

[ldhill99]

I have been having overheating problems with my 93 explorer ltd. for months. I have replaced the water pump, thermostat, heater hoses and the thermostat housing. I am still losing coolant. The vehicle runs perfect until it overheats. The other day I noticed some dripping out of the muffler. Could this be where the coolant is going? What do I do to fix it? Help

 

[something9000]

some dripping out of the tip of the exhaust is a normal product of burning gasoline. however is its excessive or smells like burning coolant you could have a head gasket leak. However i think its more of maybe your radiator has a small crack in it and its loosing coolant thru evaporation. Do you fill the coolant thru the res tank or directly into the radiator?

 

[acschilling]

I have a 92 XLT and I might have the same problem. It isn't leaking as bad as when the heater hose from the water pump was torn. My leak isn't that bad. Good radiators are easy

 

[ldhill99]

Usually fill it through the radiator. Res. stays full. Radiator drains about a gallon of coolant and motor overheats

 

[1994Splash]

How does your oil look? Is it milky? If so it could indicate that you have a blown head gasket.

 

[acschilling]

I think you have a hose leaking...when I was loosing that much, that's what it was...

 

[something9000]

if its leaking that much you have to able to see it dripping/streaming/pouring from the vehicle

 

[acschilling]

That's what I'm sayin...a gallon! I could watch mine stream to the ground it was leaking so bad...about at least an overflow tanks worth a day...get dirty and visually identify it

 

[surf]

Other potential areas to look at are the timing cover
and lower intake manifold.

 

[JCat]

It could be your head gasket.

The professional way to diagnose it would be to:

1. Get a Compression Testor and test each cylinder.
.
2. Get a cooling system pressure testor and test the cooling system.
.
.

 

[DasBaldDog]

If it's a gallon, check your oil. If there is NO coolant in your oil (losing a gallon at a time, remember) then I'd say LIM gasket.

 

[Nedwreck]

Usually fill it through the radiator. Res. stays full. Radiator drains about a gallon of coolant and motor overheats

Wait.

This is a major clue right here. (in my opinion)

One of my Explorers has a gradual coolant loss.

The other one used to lose a lot of coolant before it "gave up the ghost".

and the old one (it's a parts truck now) had a coolant problem too (heater core).

All of my explorers would suck the coolant reservoir dry before the Radiator lost it's level. (I just keep my res. topped off, and life is good)

Every time they get hot they push coolant out, when they cool off they draw it back it.

We don't know how many heating cooling cycles it takes to lose a gallon, if it's like a gallon lost every time you drive it, etc..

I would check the radiator cap, the small line to the Res. tank, and maybe clean out the tank if needed.

 

[geosnooker2000]

Get it block tested. If it has gas fumes in the coolant, you have a cracked head/blown head gasket/cracked block. If you drive it long enough, does it push so much coolant into the overflow tank that it pops the top off of it? That's what mine did. = Cracked/warped heads.

 

[ldhill99]

There is no coolant in the oil or oil in the coolant There are no gas fumes in the coolant. I don't want to replace what doesnt need to be replaced. I don't have the money to do a lot of guesswork

 

[something9000]

so you see no visible signs of a leak at all?

 

[DR_APLET]

well we all need to face it, the 4.0 is notorious for blowing head gaskets and heads. i just bought a donor and the guy gave me every record on the car since new... he had symptoms since the truck was a year old. i replaced 2 on one X in a year and a half. had one and ran it 3 years with a blow head gasket till it died. the valves were made too close together the heat of the exhaust and cool of the intake make that the prime place blow out.

people please dont fix radiators, heater cores, water pumps, thermostats or any thing else with out checking the heads.

you may have symptoms like above said items but dont bother with them if you wont spend the few dollars on diagnosing the heads first your wasting your time. that IS your problem, as a man with much 4.0 experience with blown head gaskets.

 

[tjsxplodr]

I agree with the above....check your compression and check the cooling system. Sounds like a head gasket to me.

BUT, i had a small leak, and mine turned out to be a bad radiator cap, so start small, then work your way up to the big stuff.

 

[Nedwreck]

I agree with the above....check your compression and check the cooling system. Sounds like a head gasket to me.

BUT, i had a small leak, and mine turned out to be a bad radiator cap, so start small, then work your way up to the big stuff.

I agree! (!)

I used to overlook the coolant tank and cap, until I realized how vital those sub-systems are.

The mention that the coolant tank level never changes, but the radiator looses coolant is a big flag in my opinion.

It's at least worth a good look and check - easy and free too.

Hopefully that's all it is. One can hope, yes?

 

[Backwoods "X"]

Seems like the 1st Gens. have history of doing the"missing coolant" trick...our 94 is wanting to STAY at a little over 1/2 full in the radiator, but everything else is seemingly just fine...

 

[DR_APLET]

heres my soap box again,
here is what happens... if a particular component fails (thrumostat, radiator, overflow...ect) the motor overheats this in turn weakens and already weakened head gasket it fails, causing other major issues like misfire, leaking heater core, leaky hose, radiator, overflow, thrumostat water pump... this list goes on. people usually address the simple stuff and never ask why this happened. these components DO NOT fail regularly with out other cause. i know despite its reputation thermostats are not usually the problem.
Why...after a head blows pressure builds destroying the extraneous parts like heater core. this inturn overheats the motor again exacerbating the problem. my experience with this motor is that you will not loose a gallon of coolant of water to a cap or overflow, once you loose a pint or so the and drop the level below the reach of the cap. its not that. same with the overflow. if you cant see the leak (a gallon would be obvious) then think interior could be heater core but you would probably smell and see that(wet carpet puddles under the passenger front tire) its probably interior. Probably the #2 or 3 cylinder. the water does not usually make it to the oil because the blow occurs from the water jacket to the exhaust valve or between the valves, if you see any steam (smoke vapor) during the summer your gasket is the cause, a few minuets in the winter, in really cold places you will have other issues and could be hard to tell from the exhaust. once you fill the radiator to the neck of the opening with the car running at temperature look for bubbles or smell the water for exhaust. these are indicators not all head gaskets have these symptoms. Dripping from the exhaust is a pretty good indicator.

It could be your head gasket.
The professional way to diagnose it would be to:
1. Get a Compression Testor and test each cylinder.
2. Get a cooling system pressure testor and test the cooling system.

i like Jcat's answer, but i have see them test good on compression but still have a blown HG. a leakdown test might be more comprehensive.

my brother once against my advice took his x to a "mechanic" for a misfire. they replaced the spark plugs... after 2 weeks the mis came back then another "mechanic" who replaced the radiator, heater core, thermostat hoses and plugs, after $2500 he let me help him with the gasket found a cracked head on #2 junkyard head and back together has been running well for a few years now.