Greetings all.
I'am a newbie to this site. Glad I came across it.
I drive an 06 F450 with the V10 and have a about 33,000 miles on it.
A few weeks ago after coming down a long grade (18 miles) and using the tow/haul mode to hold back the speed a give the service brakes a rest I got the MIL on the dash to come on and the truck went into limp mode. I shut it off and did a quick restart and all was good.
Since then it has happened to the point where it is almost daily now.
I believe it is a electronic problem and not the thermostat or cross-over pipe.
Does anyone know where the cylinder head temp sending unit or coolant sending unit is located on these engines. Next time it happens I would like to disconnect the sending unit and see what happens since the dealer cant make it overheat by looking at it in a service bay (DUH!)
I see some people have had have ford buy the trucks back, I really dont what that option since the truck would have to go to a upfitter to re-place the bed with a aerial lift bucket and all the goodies on it now.
Any suggestions are much appreciated.

 

Aloha,

Your truck has a number of TSBs (Technical Service Bulletins) that deal with that very issue.

Some have had get to a new thermostat while others needed the PCM recalibrated.

Check this out. https://www.ford-trucks.com/tsb/tsb....6/d-F-450%20SD

And make sure you check in down at the V10 forum!

 

The TSB you're looking for is:

https://www.ford-trucks.com/tsb/full...p?tsb=06-21-15

False overheat for the 5.4 and 6.8 - involves a new crossover and thermostat.

 

I would like to know where the sending units for either cylinder head temp or coolant temps are located. Next time (probably tomorrow) it acts up, I would like to disconnect the sending unit and see what happens. It's a company truck and if it goes to the dealer for repairs it'll be gone at least 2 - 3 weeks before I get it back. If I can isolate the trouble to a sending unit I might get a faster turn-around.

 

I have been told that the cylinder head temp (CHT) is a calculated (Educated Guess) number from the trucks computer based off the reading from water temp sending unit. Only one sensor.

I would have the TSB # in hand next time you go to the dealer. Changing the crossover tube and T-stat should take little time. Parts should not take more than a day or two to arrive at the dealer. Most parts come next day.

 

I got a couple of codes once when my acc belt broke, they both were cyl head overheat. Don't know if it comes from the CTS or if it actually has a couple head temp sensors.

 

The 2-valve V10 does have a CHT sensor, as well as (I think) the 3-valve.

I remember someone posted in the V10 forum about that once, and I went and researched it, and found replacement procedures for both the 2-valve and the 3-valve CHT.

The F150 and passenger-car engines interpolate cylinder-head temp from the water temp sensor.

 

Just checked, and at least for 2007, there is a procedure for replacing the CHT on the 5.4 and the 6.8.

2007 F-Super Duty 250-550 Workshop Manual

 

Your probably right. A while back in the V10 forum I brought up CHT and FTEKen said that it was a calculated figure.

 

That's who I was talking about - all 2-valve and 3-valve V10's do have it, and apparently, so do the 2 and 3-valve V8's in the Superduty.

On the F150 and passenger-car engines, it's calculated and not a real sensor.

 

Well, I took it in to the dealer yesterday. I should get a call from them next week to see what they find out.

I wonder if the first dealer actually did change the t-stat and bypass hose?
Seems like whenever the tranny would hit 5th gear is when it would think it was over heating. I still think that its an electronic glitch and not the t-stat.
I'll post again after I hear from the dealer.
Brian.

 

Any updates I'm haveing the same issue 2006 5.4 Lincoln Navigator but mine does it once in a while takes about a 2 hour drive to make it happen replaced coolant temp sensor and oil press sensor. Other then that same issue. Pull over 1 minute and back down to temp ready to run might get 3 miles then back again. Or might go 60 miles.