I've tore through this forum and many others on this issue but wanted to get some insights before I am forced to sell a child to upgrade everything....

I towed my pop up camper across the US and had no issues whatsoever, this last weekend on an Elk hunting trip I drug it up the mountain (11,000+ ft elevation) I smelled coolant and when I looked under the hood, I had puked coolant out of the reservoir cap. I had the AC running and was doing 50-75 up the mountain so the engine was doing some work. The temp gauge also never moved, and the truck did not overheat (dash gauge, I haven't added real gauges yet)

I have read this could be:

EGR Cooler
Headgaskets
Stretched bolts
Coolant Cap
Oil cooler

I know I need a new cap as driving it around town it will puke a bit of coolant now, so going to get that today.

My question that comes in is that I never had an issue at all until I really was using the turbo/tow going up the mountain - could this just be the extra extended load I put on it and a faulty cap? (wishful thinking I know)

Also I noticed my heater valve (I think thats what its called) is leaking and needs to be replaced - could that cause some of it?


Just so this is out there, I fully flushed the coolant system and replaced the Ford coolant with Final Charge, and added a coolant filter before I went on my cross country trip, I also changed the oil and fuel filters as well. The only mods this has done to it are a K&N CAI (I know, I know, it was on there when I bought it) and the blue spring upgrade kit for fuel pressure.


So with all that, any ideas?

 

Sounds like the typical 6.0L PSD problems, but I'm only guessing right now.

What engine do ya have in your rig? 5.4, 6.8, or 6.0?

Stewart

 

Sorry forgot to mention that, its an '03 6.0L

 

When we got our 2002 6.8L last year and was using it to tow a 7k trailer it would push coolant out of the reservoir.
I read a thread awhile ago about the reservoir tank markings not being at quite the right levels.
Don't remember, but I can't see why the engine would make any difference.
I think you have the 6.0 diesel so it has the huge trans fluid cooler.
I marked the reservoir with new levels about 2.5" lower and have not had any overflows since.
The dash temp gauge never moves because it is the usual "idiot gauge" and always displays Normal.
The OEM radiator cap does have a smallish pressure relief spring.
The Stant radiator cap has a larger spring.
I would replace the radiator cap, replace the heater cut-off valve, mark the reservoir tank lower, get a real temp gauge and try it out again.
I'm adding a real temp and oil pressure gauge soon.

 

Any idea what that heater valve part number is? I've found some on rock auto but they all look different than what I have.

 

Do the 7.3s not have this issue? I can't recall someone discussing this with a 7.3L.

 

Our V10 has a rear heater and uses a 3 port valve - Motorcraft YG357.
The 3 port was used because of were the tubes come together in the V10 engine bay.
Our 2003 5.4L uses a 2 port valve and tees off the rear heater after the valve.
The 2 port version is YG257.
The 6.0 may use the YG389, but it works the same as the YG257.
I relocated the valve and hoses in ours to gain better access to the fuel pressure test port, PCV and IAC.

 

They can have this problem, they aren't immune, but it isn't a common problem like with the six-ohs.

Stewat

 

My guess is the coolant reservoir won't fill up and overflow until the coolant temp gets above 200 deg or so.
Won't know what the V10 temps are doing until I get a real temp gauge installed.
By keeping the coolant level a bit lower in the reservoir there is more room in the tank for coolant when the engine gets real hot, like towing up a hill.
The 7.3L may not ever get over 200 deg so no problem.

 

I'm not sure why you think getting over 200* degrees would cause the coolant to overflow. Coolant doesn't suddenly increase in volume over 200*

Being around 200* is in the normal operating temp range for a 7.3L PSD.

Stewart

 

You need to install a pressure gauge in your system that will reach into the cab and take it for a drive and warm it up good. Then pull over and very carefully loosen the cap off to relieve the pressure. Now take it back out for a good run and see if the pressure comes back fairly quickly. If so then you have more major issue like blown EGR cooler or head gaskets. Go over to the 6.0 forum here they have some real experts that will help you out. Good luck.

 

I pulled the EGR valve to see if there was "goo" in there or just good old dry coking - it was mostly dry in there, very very slight gumminess in the very bottom of the chamber. I had read that if your EGR was going it would be very sticky in there.

Ill go check out toe 6.0L forum and see what I can drum up, thanks!

 

You're right, the coolant doesn't suddenly increase in volume over 200 deg.
I should have left out specific temp values.
Coolant does increase in volume with higher temperatures and the level in the reservoir will rise. My point was when the level in the reservoir starts at the molded markings it can fill up completely. The hotter the coolant the higher the reservoir level, like when towing. At least that's what it did with our V10. When we first got the V10 around town driving never was a problem. Whenever we would tow the trailer a small amount of coolant would come out the overflow tube. I filled up the reservoir to the marks and same things would happen. With a lower coolant level in the reservoir there has been no more coolant loss when towing.
A weak cap can cause early coolant loss so I ran tests with the OEM cap and a new Stant cap with no differences.
The coolant temperature swing may be less in a diesel versus a gasser.

If you have a blown head gasket or cracked head start the engine cold with the reservoir cap off and you'll probably see bubbles in the reservoir coming from the engine.

 

I get the gist now, thanks.

Stewart

 

I would try replacing the cap first to see if that solves your issue. I had a bad cap at one point and the slight puking cleared up after replacement.