Moderate coolant leak.

[willtotheumm]

Hey guys. I have a serious problem on my hands. My 92 Explorer never has a problem overheating or anything. The needle is always perfectly vertical. Yesterday morning I was on my way to work and noticed it would go up to about 3/4 of the way, then cool off to almost completely cool, then go back up, and repeat.

I know that the overflow hose is loose on the reservoir end. I opened the cap to check and it was dry. I topped it off and then topped the radiator off as well (it was barely low).

I had to drive it in 30* weather to my work and back last night (2 miles 1-way tops) and it was still doing this. I get home from work today and notice a small puddle of coolant under the truck, towards the back/pass side of the engine. There is also small dripping from the reservoir end (but I just need to get a small hose clamp).

I crawled under and can't find where it is coming from, but it's getting everywhere. The coolant is perfectly green with no signs of rust or anything. The cabin is also smelling like coolant almost instantly.

I really hope it's just the heater core and not a blown head gasket. This is my daily and I can't drive my MR2 to work right now as it needs some work too.

I need to get this fixed asap even if it means just looping the heater core hoses until I can get a new heater core. Any help guys??

ALSO: The exhaust doesnt smell like coolant or anything, and does not blow smoke in any color. A few months ago I thought the heater core was going out because the windows would get foggy in the mornings with the defroster on and would smell a bit of coolant. It has since stopped.

 

[shaggymane]

Hey guys. I have a serious problem on my hands. My 92 Explorer never has a problem overheating or anything. The needle is always perfectly vertical. Yesterday morning I was on my way to work and noticed it would go up to about 3/4 of the way, then cool off to almost completely cool, then go back up, and repeat.

Sounds like a Thermostat going bad. Make sure you put it in proper side up and don't forget they use an O-ring.

I get home from work today and notice a small puddle of coolant under the truck, towards the back/pass side of the engine. There is also small dripping from the reservoir end (but I just need to get a small hose clamp).

I crawled under and can't find where it is coming from, but it's getting everywhere. The coolant is perfectly green with no signs of rust or anything. The cabin is also smelling like coolant almost instantly.

Smelling anti-freeze in the cabin is usually a heater core gone bad. Check clamps, the hoses for (pin hole) leaks. Get a pair of gloves (safety goggles too) and move the hoses around. That'll open up the hole bigger. Or get a pressure tester.

even if it means just looping the heater core hoses until I can get a new heater core. Any help guys??

That's do-able to keep rolling

A few months ago I thought the heater core was going out because the windows would get foggy in the mornings with the defroster on and would smell a bit of coolant. It has since stopped.

It's baaaaack.

 

[cogs]

watch out for backed up pressure... the valve to the heater (black plastic the hose is on) can explode when driving. then you'll have to replace that as well.

 

[92exp4x4]

His is a 92 and does not have that valve. I had one explode on my 94, that sucked.

My 94 also had coolant leaking (later and unrelated) at the back passenger side of the motor. It turned out to be the rear freeze plug on the passenger side head.

Got to pull the head to fix it, i pulled whole motor just to do other stuff to it while it was out.

Hope its your heater core, they are easy.

 

[willtotheumm]

Thanks for the help guys. I'm just really sweating it right now with the Explorer as my daily and my MR2 now won't keep the battery charged and it makes getting around really tricky haha.

I have to run to town later so i'll make sure to get something to connect the hoses together. I sure hope that'll fix the problem so I can look into whats up with my MR2 (poor newish battery heh)

 

[shaggymane]

will,
The temp fix is to find the one going from beside the thermostat to the heater core, take it off completely.
Then disconnect the bottom one and loop it to the port beside the Tstat. I call it the bottom one because it *goes down under*.

They should be the same size hoses.

 

[willtotheumm]

Awesome thanks

I went to took off the intake piping, removed the belt off the alternator, and unbolted the alternator so that I could get to the thermostat housing. The hose came off at the heater core really easy, but I can't get it off at the thermo housing. My friend is bringing an awl when he gets off work.

I'm just hoping i'll be able to start it and have no more leaks or dancing temp needle.

 

[cogs]

His is a 92 and does not have that valve. I had one explode on my 94, that sucked.

yes, mine's a 94, and assumed his was the same type. thanks for the tip shaggy, about the heater line. what i would suggest, is to see if the radiator cap, or the thermostat itself, has any gunk, or slippery stuff on it, probably dark green. if it's a little gunky, run some radiator cleaner through it. you can either do this now, or do it when you fix the heater core. i was surprised that it actually cleaned mine out so well.

 

[willtotheumm]

Yeah it has a bit of gunk on it that I noticed the other night. I'm going to get that flushed (for free heh) when I find out this problem as well as a new radiator cap and thermostat.

I just got done looping the hose. It now goes from the bottom of the water pump to the top. It was a PITA to get off, but finally got it done. I put everything back together (took out the alt for more room) and started it. No more smell in the cabin. I saw some burning off the exhaust from it pouring out and smelled that, but not in the cab.

I did however let it warmup and kept checking underneath. Only 2 small drips or so. I figure it's from the pour out from the hose. I shut it off, did something else, and then checked about 5 minutes later to find another puddle. Not as big as before, but still a puddle.

I really, really hope it's still just some over flow. I washed down the side of the engine and am going to check it again later.

As far as the heater core goes, are they all really loose? I got the hoses off and the core jiggled a bit, but when I went to put the now, unused hose, onto it (just so I won't lose it haha) I had to hold one of the spouts just to get the hose on the other, clamp it down, and hold it outwards just to get the other end on. Are they all that loose??

 

[willtotheumm]

If it isn't the core after all (although I think that was part of it), what else could it be in that region? I figure if it were a freeze plug it would pour out pretty good, which it doesn't. A BHG wouldn't leak outwards would it? The exhaust is still clean and smokeless with clear condensation dripping out (no smell of coolant or anything).

If it were the driver side of the Explorer, a head job wouldn't be as bad. This happens to be the extremely crowded side of it. How long do you think it'll take to (if I have to), pull off the head? I really don't want to. haha.

 

[shaggymane]

I've not done a heater core on Gen 1 yet.

But glacier991 has and I R helpful.

So, http://www.explorerforum.com/forums/showthread.php?t=160622&highlight=1st+gen+heater+core

http://www.explorerforum.com/forums/showthread.php?t=135049&highlight=1st+gen+heater+core

They are the same & both by glacier just posted in different sub forums so will have different responses

And yes heater cores are normally held in place, closing two halves of the case or someway

Slowdownwill, on the head gasket thinking. Lower intakes will leak coolant but I don't know that much about where. Other guys will have to respond.

Check the heater hose for leaks too. Take several layers of paper towels wrapped around the hose and wipe the length it. If they come back dry, that's good. If not keep wiping with new towels to see if they keep getting wet. Sounds redundant but you get the idea?
They do get hard, dry and rigid with age. Might be a good time now to replace them.

Got your anti freeze tester?

 

[willtotheumm]

That was a sweet write up. Gonna come in handy as I haven't done a hc before (and have to do one in my gf's 98 S-10... ugh)

Tomorrow i'll try the paper towel trick. They seem a little far forward for where the leak is, but it's all worth a shot.

I'll also crawl under it tomorrow and take some pictures of where I saw it dripping from (with goggles of course lol)

Nope no anti-freeze tester but I can swing by harbor freight or something tomorrow to get one.

 

[willtotheumm]

It's raining today so I can't go check to see if it's leaky still, but I have the next 3 days off

 

[willtotheumm]

Alright small update:

Definately no more coolant smell in the cabin. Took for a couple drives. Got to temp in usual time. Make 2 stops with no dripping. Went to another and there was a few small drops. Smells of coolant outside of the Explorer when its running, but not a lot of dripping.

On the way to the 2nd place I had to go to, the needle started going up again. Where the 'Normal' is on the temp gauge, it'll usually sir between the 'R' and the 'M'. When it's going up it's at the 'L' or a hair past. Then drops back to about the 'N', and in a minute or to it's back to between the 'R' and the 'M'.

The rest of the day it didn't really do that.

I'm still going to replace the thermostat and the radiator cap. Definately want to replace the heater core. I miss the heater at night and at 445am when i'm headed to work haha.

 

[shaggymane]

Ok, you'll want to get that Thermostat changed out rather soon. That high heat and constant change in temp expansion and contraction is not gonna be good for the heads. I think that'd promote the cracking these heads are known for
There's threads around here that say high heat causes the front tranny seal to blow.

 

[willtotheumm]

Yeah that's no good. I get paid on Monday and will pick up a new thermostat. I go OEM with everything on my MR2, do you guys think an OEM FoMoCo thermostat will be worth it? Or just one from Kragen or something?