I need help! I'm not really a forum guy so I'll do my best to describe what's going on...


I bought my Excursion 1 year ago from original owner who used it to ferry kids to and from school and tow their boat around the west coast for 15 years. I paid $2300 for it. It had 230K miles on it when I got it. I put tires on it and have been using it to pull my 7700lbs 33ft travel trailer all over the place... I put 20K miles on it in exactly 1 year (coast to coast trip, up to Denver, CA to AZ a bunch of times, etc).


3 months ago, on a trip up the grapevine with the trailer, it overheated but quickly got back to normal temp and I didn't think of it again... there was still coolant in the reservoir and it didn't boil over that I could see.


Gradually it started to overheat 3 to 5 minutes after I started it up in the morning but I learned that if I just put it in neutral while rolling, turning off the engine, restart, and put it back into Drive, the temp would go to normal for the rest of the day.


somebody here said it would be the sensor so I bought a new one... that didn't do it... somebody said it was a air pocket in the system, so I had a coolant vacuum flush done at Firestone.. that didn't fix it... Firestone said it was the thermostat, it was replaced but it didn't fix it. Then they said it was the reservoir, replaced, that didn't fix it.


Another shop ran a vapor test to see if there was fuel in the cooling system.. there was (the blue fluid turned green)... blown head gasket? cracked block? cracked head?


The check to see if it was a head gasket by pulling the plugs and doing a pressure test.. didn't reveal a leak...


The put 30PSI in the drained cooling system overnight and it didn't lose any pressure. They replaced the radiator... didn't fix it.


The consensus is that at some point air or exhaust is entering the cooling system and causing the head to rapidly overheat. but I don't understand why quickly shutting it off and then restarting the engine fixes the issue.


They tell me I have 3 options:
1) replace the head gaskets ($1800)
2) replace the heads (approx. $3000)
3) replace the engine (approx. $7000)


I've never replaced an engine in a car... am I just paying for another set of problems? would you put a new engine in a truck with 249,980 miles on the tranny and chassis?


I've already spent close to $1800 without fixing the issue.. any ideas or comments would be much appreciated. I love this truck.. it's perfect for what I do (I fly giant scale model warbirds around the country at events and competitions)

 

I can't help any with your issue but are those pictures of models?? They look amazing.

 

Yup. Those are models.

 

Did anyone suggest the water pump may be the issue? Seems too easy to be overlooked.
Awesome planes by the way.

 

I have heard of a bad pressure cap causing similar symptoms. Is it a new cap with the new reservoir?

 

BTW, someone else just dropped 11K replacing one of those million mile engines that burn oil.

 

it was replaced as well. Sorry I didn't mention it.

 

a new cap came with the reservoir

 

i was told $7K. Is $11K a better, more realistic estimate?

 

I wonder... if after startup just sitting you can reproduce this, because...

Turning off the engine "fixing" it makes me think something related to engine rotating vs sensor.

What if, when things are cold, A/C compressor locked up is preventing serpentine belt from rotating...
water pump would stop too..

Then stop/start engine a/c compressor unfroze things run normal now.

 

Sounds like you don't have a technician or a mechanic but rather a "parts-changer.

250,000 miles on a V10 is about 90% of it's life.

If (as you say) you love the truck, put a new motor in and drive it like you stole it. Currently you will not retrieve any value in it's current state.

 

Could you please describe in detail EXACTLY what it is doing during these overheating events?
You say it is overheating but hasn't boiled over but it does loose coolant, does the exhaust smell like coolant?
Are you just seeing a spike in the dash board gauge?
Does the dash gauge agree with the OBDII data?
Does it loose power, ping, rattle, smoke/steam?
Was the fuel in coolant test repeated after any of the work? If so what was that result?

 

i


i thought the same thing as well but that's why they changed the water pump and checked for blockage or issues in the heating and ac system.

 

it happens so often I feel dumb not having video... cold engine (in the morning) or after it's been sitting awhile... This engine usually does not change temp even when driving hard (up hills, etc)
It starts normally, runs smooth, it warms up (in the morning) in only a few minutes, will run normally and the temp gauge will be on the low end of the temp range.
after running 3 to 5 minutes the temp gauge will spike to max temp and the engine will begin to shake (I think this is limp mode). If I put it in neutral and shut and restart the motor, the temp gauge will immediately go to normal temp (low end of the gauge (needle about 2/5 up the gauge)


If the restart doesn't work to normalize the temp and I open the hood, the pressure cap does release coolant out of the reservoir).


The reason I posted here is because day before yesterday it got a lot worse... a hole appeared in the new cap and it let all the coolant out... I put 5 gallons of 50/50 in that night to get home... next morning I got a new 16PSI cap from Oreily and put in fluid with the engine running with the heater on front and back... I waited for the coolant level stayed level after 30minutes... It ran fine for 50miles (no temp changes even 75MPH up a steep grade)... I thought maybe it was a air bubble that got into the system.. it sat for about 3hrs and then on the way home - approx. 65MPH it happened again... It blew the new cap off the reservoir and covered the engine in gallons of 50/50... I walked to a Walmart and bought 4 gallons of 50/50 and it took all of it.. it started normally at that point and made it all the way home before it spiked temp again pulling into my parking space. It sits there now and I'm wondering what to do.

 

Also.. when the shop checked the engine code it was something like "head overheat"... it'll stay cleared until the next time it spikes the gauge...