Coolant Leak / Heating Problems

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How's it going guys. I've been having a couple issues with my '98 expedition 4.6 150,000mi recently, and I need some idears. Not sure if these issues are linked, but I'm thinking so.

#1 My front heater is cold to weak at best. Although when I give it gas the heat does it improve, but when I come to a stop light or let off the gas it goes back to being luke-warm to cold. If I drive and turn the heater off for a couple seconds, and turn it back on, it shoots out hot air, but then cools off again. Or if I park at a grocery store, and come back out the heater is hot for a few moments, and then goes cold again.

What's interesting is my Back heater produces great heat, and right now is what I'm using to warm the vehicle.

#2 I also have a coolant leak where the top radiator hose connects to the radiator. I have a band clamp on it, and tightened real well, but after driving it seems to build pressure and squeeze out between the plastic and hose. The top hose will build pressure, but it's not rock hard. I was also curious if it's supposed to be hot, because I can grab it and hold it. It's warm, but not hot. I also noticed that it leaks its worst when I fill the reservoir to the proper level. Once it leaks down to under the cold fill line the leak seems to slow or even stop. In 2008 the dealership changed out the radiator, hoses, and tstat for the same leak I believe.

The truck runs great, no overheating issues what so ever. Hums right along.

I appreciate any ideas guys.

Thanks
 

IMINYOURCHAIR

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low coolant level not allowing proper idle flow to the core. when he gives it throttle it warms up. address the coolant leak then we can go from there. I think it may be the problem. Mine lost heat to the front heater on the way home when the coolant ran a little low and revving seemed to push coolant into it.

after that leak there is a tree to follow.

1. Is the engine reaching operating temp? the needle on mine rests about between 1/4 and 1/2 at 195 deg f according to my obd scanner. if not you may have a stuck open t-stat as stated above but having hot rear heat seems to point away from this

2. are the hoses to the heater warm on both sides? if the return hose is cool/luke warm this can point to a clogged core. back flush the core in that case

3. least likely, has the water pump been replaced recently? it could have a bad impeller **read as the blades have rusted away

but, as I said, address the coolant leak then we can go to the next steps.
 
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I agree with you that the leak is the start point. Not sure how to tackle it. Radiator, hoses, and tstat were all replaced in 2008, but that doesn't mean something isn't broken now.

1. The temp gauge goes right to the middle after a bit of driving like it should. And the heat from the back heater is enough to make the top of my head almost burn.

2. I have not checked the hoses to the heater. I will do that tomorrow. I assume along the firewall in a nice tight spot somewhere? lol

3. As far as I know it's the factory water pump with 150k miles. Been waiting for an excuse to replace it, but it just keeps going lol.


But back to the leak at the radiator, any thoughts as to why coolant is being forced out at the top where it connects to the upper hose? I will check tomorrow, but I believe it stops leaking once the coolant reservoir reaches a certain level. Maybe once it's even with the top radiator opening.
 
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bedrck46

is it possible that the connection has a crack in it and even though you tighten it down it still leaks??
 

IMINYOURCHAIR

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is it possible that the connection has a crack in it and even though you tighten it down it still leaks??

that's what I'm thinking, I would remove the hose and inspect that area rigorously for cracks. Couldn't hurt to add some UV dye, run it for awhile then bring a UV light while looking for the crack. Coolant leaks are tricky little gremlins sometimes, ask me how I know ;)
 
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It's very possible. I took the top hose off the radiator and inspected both for cracks, but I could have missed one. I was thinking about replacing both the radiator and hose anyway since it wouldn't be too terribly expensive. This weekend I'll pull the hose again and inspect it more closely.

Would be happy if it were as simple as a crack somewhere.
 
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bedrck46

if its a crack in plastic you might try PC7 for a temp. fix
 
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So I haven't added any coolant in the past couple days, and it hasn't leaked. It seems to only leak until the coolant gets a little under the "Add cold" line in the reservoir. If I were to add coolant, it would leak from the radiator/hose until the reservoir reaches below the add line again. Problem with that is, with it being slightly low on coolant all the time, the heater probably can't do its job.

Also checked the two coolant lines going to the heater core at the firewall. The top one was hot, but not scalding hot. I could hang on to it. The lower hose was warm, but not as hot as the top. Maybe a little blockage there?

Good idea on the quick fix. If it starts leaking again after I add coolant, I will try that until I order a new one.
 
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I should also note when I checked the radiator hose there was a muddy/rusty color film inside. Not super thick, but definitely there. I think I'll try to flush the front heater core tomorrow and see what that does. Haven't followed the heater core hoses yet, but I hope there is an easier spot to pull them off than the firewall. lol
 

IMINYOURCHAIR

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If you want to save yourself some time in the future, just break off the quick connects, then cut the hose as close to the end as you can. Reattach the hoses using the screw on clamps.
 
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Ran some radiator flush for a bit today. Did not seem to unclog the heater core if that is the issue. But I did get some nice nasty coolant out of there. Refilled with green for now.

Also replaced the top radiator hose to hoping that the old one was getting wimpy.

When it warms up I'll try to disconnect the heater core and see if I can try to flush it separately..
 

ediddily

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I have an '07 XLT and recently been having the same kind of problem...
I drive somewhere and a coolant leak springs out, not a lot though, maybe a cup or so...
I did a flush without a clean as my heaters work front and back and have all coolant in there now...
The leaks comes out mainly on the front passenger side above the top radiator hose, at times it will go to the driver side with a little less...
I need some pointers as where to look...
Could it be.....
-a bad hose
-a cracked hose flange
-a cracked radiator

This is a funny thing too because Ill drive 20 minutes one day and nothing, then 10 minutes another day, park and it leaks.

A key thing is that it only leaks when its PARKED and turned OFF!
 
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chucks97expy

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Hi expeditionstig, just went through some problems with my 97 expy and thought I'd post. For starters, last year when I bought the truck (has the 5.4L) it needed a heater core. It was leaking at back of motor above transmission. I did it myself and saved about $700. Not a hard job but it is time consuming for sure(awesome step by step on youtube) So after I replaced it, I flushed the system. Or so I thought. Well yesterday here in Chicago it was about Negative 30 with wind chill. I had no heat. I let it heat up to operating temp and still no heat. Got to work with frosted windows and it was just starting to blow warm. Rear heat was Ice cold. I was at a loss. I replaced the (blend door) when I did the heater core. Its a door that swings back and forth like a door in your home. When you select warm it swings one way and when you select cold it swings the other. All this is done by a small control under the blend door, that sits under the dashboard. Its called a (heater blend door actuator) So I go on Ebay last night and buy it. $30. Well I get the big truck into my garage today(barely fits so I leave out in front) and let it thaw out. Low and behold I have heat and rear heat after the thaw. I took it straight to Jiffy lube and had the "radiator system flush" . You would not believe how much "gunk" came out of the system! because of the rear heat and all the hoses, you simply can't get it all with the "over the counter" flush and fill kit. It costed me $140 but I have heat in both front and rear now. So the "non heat" issue could be a few things. My truck is a 97 with 137,000. Heater core was bad/replaced. Blend door actuator could be hanging up and not allowing heat in the front. Antifreeze (if gunky) was my problem(even after I thought I did a good job flushing it out) Hope some of this helps
 

Arod132

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97 XLT expo

Hey guys I'm having the same issue Front heater blows cold back blows hot when car is moving front get warm then cold again , then the temp goes up to H then overheated light comes on then I have to stop truck for a bit , then start leaking antifreeze from top of reservoir tank , then truck drives normal but still blows cold in front I change thermostat ,water pump, alternator ,radiator ,hoses I c no leaks from core .any help


Andy
 
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bedrck46

For Arod132 Andy for a quick fix take the t/stat and drill a small hole through the plate no bigger than 1/8 inch Friend had same problem was told he had a blown head gasket but we had no signs of a blown gasket or leaks or water in the oil or coming out the exhaust we drilled a small hole and he hasn't had any problems since It won't hurt to try and if you do have any serious problems they will still show up if you do this kindly update with the results
 

Arod132

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For bedrock I'm looking into different thermostats .I got one think that opens at 180-195 degrees but I just seen one for ford that opens at 160 The way I'm losing antifreeze seems like the thermostat is always closed cause the top hose from radiator is cold after 15min of a running engine
 
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Thanks for the tips guys.

I haven't had a chance to mess with it recently with the cold weather, and busy with classes. I replaced the top radiator hose, and radiator cap just to knock out some older parts. But coolant is still being forced out where the top radiator hose meets the radiator, and still low front heat.

If I have time this weekend, I want to remove the front heater core hoses and try to shoot some compressed air in there, and hopefully fix the heat issue. Then I can figure out why coolant is being forced out at the radiator. Money is kind of tight, so I'm holding off taking it to get the radiator flushed out until I know for sure.

Truck runs like a top otherwise though.
 

JUST4FUN

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The aftermarket Tstats are junk go to ford and get the one that it was born with. this has the hole that bedrck46 is talking about
 
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