Just changed water pump some hoses, lower thermostat,and thermostat housing on a 2002 Excursion (engine build date 7/15/2001 - so converted to red coolant).

Before this was done I saw that I was loosing coolant but attributed it to the thermostat housing or hose due to the wet on the top of the housing here:




After replacing all those parts the issue persists. Since the coolant has been changed the truck has been driven at least an hour and probably not more than three. I've had to top of the coolant at least 2x - from the max line to below the min line.

This morning before starting it up I marked a line, drove about 6 miles to get fuel and came back. After letting it cool, this is the amount of coolant lost:





There don't seem to be any external leaks.

Last night. when starting it cold there was a lot of white smoke, but it appeared to be coming from the outside of the exhaust pipe as much as the inside. I'll continue to watch for smoke on startup but can't say anything for sure about that yet other than his morning I did not see any white smoke.

After sitting for a few hours, cracking the radiator cap produces a hiss.

The oil level appears to be normal, so it's not going there.

I've looked under the front end and the rear where the cooler likes go up the the heater core and found no leaks.

Where do I start looking to track this down?

 

As for the first picture, Was this picture prior to or following the work? Did you replace the T-Stat Housing? They are flimsy pressed aluminum and perpetually leak. Most replace when changing the Water Pump.

It's not uncommon to have to top the coolant off following repair or maintenance.

A leak can take several direction and end up just about anywhere, to include the valley. Which, will not evaporate readily.

Some things to consider:

1. Pressure test the system to 16 - 20 PSIG and evaluate it after an hour.

2. Did you clean both the mating surfaces where the hoses connect?

3. Spraying the hard mating surface with Hair Spray will seal it AFTER it's cleaned. The only down side, you may have to cut the hose off next time.

 

First pic was prior.


Yes, with a billet one.


Yes, I understand. This just seems way more than the previous time and since the coolant was uncharacteristically before the work, I'm wondering if the coolant at the thermostat housing top was a symptom rather than the cause.


Ahh, I will take a look there.


I can say that it held some pressure for ~2 hours based off the hiss I got from removing the cap.

I also noticed that the level is now back up to the top line - right after shutting down and at full operating temp. I assume this is normal that the acid test will be where it settles when cool.

[edit]
The line I'm talking about is the sharpie line marked 11/19 c 11:55.
[/edit]

If it's a head gasket, then don't I want to determine that before pressure testing so I don't force coolant into the cyll?


Yes. The only "old" mating surfaces were the 3 radiator connections and the top degause tube. All the other parts were new. There's no sign whatsoever of coolant on the replaced parts.


I did not try the hair spray trick. I did use new hoses.

 

Was it the one from Dieselsite.com? Myself and a few others have had difficulty getting that one to seal. The leak I had was so small I could never find a wet spot, but over time my coolant level continued to drop so I knew I had a leak. A little RTV will do.

 

After I replaced the coolant in my engine with ELC red coolant I expierenced almost the samething you are. I had to put about 200 miles on mine before the coolant level settled down. I was getting really frustrated with everytime I checked mine when good and cold it was always a little low. My oil level was always ok. My degas bottle cap does hiss if I crack it open several hours after it was warmed up.
Bill

 

It was from RiffRaff - I don't know how different that one is from the one you mentioned. The drop in the 2nd photo was only after only 6 miles.

If it comes to it, I'll rubberband a paper towel around all the connections to see if they're a problem.


The question I should have asked first is how long has it taken for antifreeze to stabilize after a flush/fill. In the past, I've always been good after a 20 minute drive. I top it off and have been good to go from there. Maybe that's not always the case....

 

Thanks for sharing this - wow - that's a pretty long stabilization time. At least now I know there's a possibility that the problem can be solved with time.

Were you getting large drops in coolant - where you had to put in a couple of quarts to get it back to where it was before?

 

After the engine rebuild I had to top mine off 3-4 times (also about 200 miles) before it settled down. Run it up to normal operating temp a few times so the thermostat opens.

 

Another one. We almost have a trend here.

It's an Excursion, I've been making sure the front and rear heat blow warm to ensure the coolant is cycling through everything.

 

I have *something* in the valley. I think it's oil or fuel. I shoved some paper towels down there and got some black nasty stuff, but no sign of red.

If coolant ended up in the valley, where would it come from?

 

The Fan pushes it back from the T-Stat Housing and then it will eventually run out the weep holes and on the ground at the almost rear of the engine.

 

I should have added in my previous post that I was referring to my Excursion. They have some additional plumbing & other items.........

 

Our truck in signature had to be topped off three times to work out air pockets with the flush/fill.

 

Can I build a pressure tester with a 0-15 psi fuel gauge (analog with NPT fitting on the back) and a schrader valve and tee it into the small overflow line?

If yes, does anyone know the size of that line is 3/8"?

 

I keep mine at that level. For some reason it likes that level. Never goes below it though. Takes about 3 checks before it stabilizes after water pump or fluid change.

Is the lid on your degas bottle leaking?