I lost coolant.... but where?

[BHop]

Hi there,

The X has about 118XXX miles on it. I keep on top of maintenance and runs great.

It was a little chilly this morning but what do you expect it's almost the end October. I back my truck in to my garage to load the rear hatch. I pulled out of the garage, and jump out to close the garage by hand and found a small puddle of coolant on my garage floor. Looked where I parked in my drive way over night and didn't find anything on the concrete.

So I didn't think too much about it and went about my planned routine. I stopped by the autoparts store to drop off some used oil and contrainers. As I approached my truck, again, I found another small puddle. Both times, no tracable location from where it was spilling out of.

So on we go to carry out the rest of my duties and... nothing. No more spills that I can see after arriving at any my stops. I make it home, pulled the x in the garage, popped the hood and..... nothing! Aside from the sweet smell of coolant, nothing! No leaking on the engine block, rad and related hoses. Naturally, I didn't open the rad cuz I was just operating it.

Did this come from my coolant reservoir? I didn't allow my truck to warm up, I just start and go pretty much unless it's really cold.

I want to note that, when I looked under my hood, I wasn't super thorough but it was more like a general look over. The coolant in the coolant reservoir was low, but then again it was low to begin with: I don't recall just how it was to begin with.

Thoughts...

 

[Todd R]

Could be a small leak around your water pump, that is my problem and I have the same conditions. Look around while it's running you may see the leak.

 

[koda2000]

could be your water pump seal is worn out (especially if it's your original pump. ditto the radiator at 118k) or it could just be a hose or a lose hose clamp. the water pump has a small hole in the bottom called a "weep hole". this is where you'll see antifreeze leaking from if it's the seal. you're gonna just have to look for the problem.

 

[swshawaii]

If it's the 4.0L SOHC, check the lower thermostat housing first. Common for the threaded
sensors or the welded seams to split. Recommend upgrading to the newer RH144 housing. GL

http://www.explorerforum.com/forums/showpost.php?p=2931233&postcount=3

 

[deweyville65]

cold water leak on big trucks was common before silicon hoses and spring loaded clamps. Probably the same thing you are experiencing when cold, disappears when warm. Check hose clamps for tightness.

 

[Chikar]

I had a similar problem with my 99 4.0L OHV. Coolant disappearing but no sign of where it was leaking.

I eventually found out it was leaking from what started as a very small crack in the heater water control valve. It only leaked when the engine was hot and the cooling system pressurized. And then it dripped on the exhaust manifold and evaporated.

Over several months the crack got bigger and it started leaking when the engine was started but still cold.

 

[corkey]

i bet it's an ohv engine,,


look here too,
http://www.explorerforum.com/forums/showthread.php?t=305166

 

[BHop]

Yes, it's an OHV.

There doesn't appear to be any leaking when the vehicle gets warm enough/operating temp. Because it's cooler outside, it takes a little longer for the engine to get warm and that's why I think it leaked when I arrived at my first stop, but nothing afterwards. BTW it doesn't leak over night for example.

I will have a closer look at it tomorrow (I hope). So I may need a new water pump seal. If that's the case, should I replace the water pump too?

Yes, everything under the hood which is cooling system related is stock. I will have another look at the hose clamps.

I have never heard of a heater water control valve, but going by what Chikar has stated, I don't think it's what I am looking at as it doesn't leak when hot, nor is it evaporating on the exhaust manifold.

Thanks, and I will keep you guys posted!

 

[koda2000]

you can't just replace a water pump seal. so yes, you'll need to replace the pump if that's where it's leaking from. btw, water pumps seals usually don't leak only somethings. to me it's sounding more like a hose, gasket or housing leak, as it only seems to leak after a cool down and not once up to operating temp.

your truck may not have a heater control valve. i can't remember when Ford started putting one on (98 maybe?). and again, once they start leaking they don't tend stop once they get hot.

 

[budwich]

IF the puddle is on the ground on the passenger side of the engine, then likelihood is great that your heater water control valve is a problem. Lot's of posts on this issue, quite common and based on experience ...

 

[Chikar]

If you follow the heater hoses from the heater core they will connect to a black plastic, vacuum controlled, valve. At least they do on my 99. The valve shuts off water flow to the heater core when Max A/C is selected.

 

[BHop]

So today, I tried to locate the problem in hopes that I would be able to fix it. I popped the hood, allowed it to run and... nothing. No leaking what so ever. I allowed the engine to idle until I was done looking around the engine bay (which was more than enough time to bring the idle down to what you would expect at operating temp.) Still, no leaks.

Seems kinda unusual to me. I really don't know what to say except that I will be keeping an eye on it.

 

[Chikar]

Yes, keep an eye on it. If it acts anything like my 99 did it will become obvious before too long where it's leaking.

I replaced the heater water control valve when it finally starting leaking so much the leak source was very obvious. Of course, just for fun, the rad blew about a month later. I had a heck of a time finding a rad. Ford didn't have them, aftermarket rads had the wrong size trans line connectors, and on and on.

I just noticed you're in Victoria, I'm up in Ladysmith. You getting rained on as much as I am? I hate our rainy winters.

 

[koda2000]

tip: put a piece of newspaper under any suspected leak points. even a single drop will be very obvious.

 

[BHop]

Yea, I am getting plenty of rain alright. Typical fall on the island! How is it on your side of things?


As per using the news paper, it's not leaking when it's off. And it's not necessarily leaking when it's on too, lol. Coolant in rad is also full. Just gotta wait this out a bit longer, and when I notice a loss, set up the news paper.

 

[2009KVFD976]

Im having almost the same problem with mine. i just flushed and filled my cooling system on my 01 ex 4.0 sohc and when i first start it in the morning, it will drip. then after about 2 mins, no more....

 

[Chikar]

Rain on the Island

Yea, I am getting plenty of rain alright. Typical fall on the island! How is it on your side of things?


As per using the news paper, it's not leaking when it's off. And it's not necessarily leaking when it's on too, lol. Coolant in rad is also full. Just gotta wait this out a bit longer, and when I notice a loss, set up the news paper.

Loads of rain for the past week or so then today the sun came out!! Neither of us are likely to see the sun very often for the next 4 or months though :-(

Re your coolant leak, they will drive you crazy looking for them. But, sooner or later, if you do actually have a cracked part, leaking hose, whatever, it will get worse and become obvious