I am having a problem with the V-10 in my 2001 excursion.

I believe that this problem started when the truck overheated while I was towing a trailer. After the truck overheated I replaced the radiator, thermostat and water pump.

Since then I have been having an intermittent problem. Occasionally the temperature gauge will immediately spike to full hot and the temperature warning light and CEL come on. The error code set is cylinder overtemp. The engine drops power and from my research I believe that it is turning off 5 cylinders to help cool the engine.

All that I have to do is turn off the engine and restart it and everything is fine until it does it again (anywhere from 30 minutes to 5 days).

I did a compression test on all 10 cylinders and they were very close to each other.

At the same time this happens, some coolant escapes the system. I believe that it is coming out of the radiator cap but I am not 100% sure.

I have replaced the coolant tank and radiator cap and the problem persists.

I am inclined to believe that it is a head gasket problem.

Has anyone heard of a similar problem and what caused it?

Any other questions?

 

air in the system?

 

Check and verify that your fan clutch is working properly .
Good luck

 

Gotta second that...

Air gaps might be causing the sensor to spike.

 

That was my initial thought but I don't think so. This has been going on for a year now and I have to believe that I would have all of the bubbles out by now. I filled it with the nose up an incline and let it idle for a while.

I know that it is pushing coolant out somewhere in the system. I believe that it is either relieving pressure somewhere in the system or introducing pressure from combustion but I am not sure.

 

My first thought was a head gasket as well---have you performed a system pressure test or leak down check yet?

Are there any signs the coolant has escaped from the radiator cap? Oil/coolant mixed together?

 

Ford has had some issues with the radiator cap. It can loose spring force and allow the coolant to loose pressure and boil off.

Try replacing the cap with a new one, it might just be the easiest fix around.

There was a video about this on powerstrokehelp.org in regards to the 6.0l head gasket failures possibly being linked to early boil off of coolant damaging the gasket.

Oddly enough in the past the radiator cap on the trucks are the same as the ones used on even the smaller cars.... go figure.

 

Apart from having different capacities to deal with heat generated by a particular engine automotive and light truck cooling systems tend to operate in very similar ways, under the same pressures. For me its kinda nice knowing a part is common and not too vehicle/engine specific.

Good info on your post Shogun6!

 

I have put on a new radiator cap and it did not have any effect on the problem.

 

[QUOTE=Wren;11763638
At the same time this happens, some coolant escapes the system. I believe that it is coming out of the radiator cap but I am not 100% sure.[/QUOTE] Expand on this, please.

There are visible signs of a leak around the cap area?
How much coolant loss do you notice? And over what time period?

 

There is no coolant loss except when it does the overheat/spike the temp gauge thing. When it does the overheating thing all of the coolant is lost at that moment. It is enough to drop the level in the radiator overflow tank about 1/2".

I ziptied a shop towel around the radiator cap. It stays completely dry except when the incidents happen and then it is completely soaked afterwards. That is what makes me think that it is coming out of the radiator cap. It could be coming out somewhere else and splashing on the cap though.