Engine temp running hot when during in town mail route
 

Hello everyone,

Transmission has not spit any more fluid after adding the larger Trans cooler and sealing the dip stick tube!

Yesterday was my wife's first day running a new much longer 8 hour route. Half way through the route I received the call that she was hearing a slight knock and it was studdering a little and "doggish". This happened after she had to stop and shut off the Jeep to deliver to a Residence home. Was running fine before hand, then this started after getting back and starting to vehicle to continue on with the route. Not knowing what is causing it (since the Jeep has been running fantastic) I had her pull over and shut it off while I jumped in the Expedition and raced to her location.

I checked the Oil and it was exactly where it was supposed to be, so we just transferred everything to the Expedition and I drove her the rest of the route.

When we returned later in the evening the Jeep was running great again and I drove it home so I could look things over and see how it was doing. I was watching the Temp needle creeping to 100c, and then drop a bit, then slowly creep back up and repeat. This I take as the Thermostat is working just fine. Zero issues on the 20 mo ride home and all was well.

Today she had her usual short in town route in our town. I was watching for her to come home and she stating the same thing happened when she had to stop at residence Home here but went away after some driving. I looked at the temp gauge and it was sitting at 100c (212F) then I heard the electric fan kick in.

Check the Fluid and it is a nice Green since the Jeep had a Flush and Fill in 7/21/18 @ 269,300 km

Things I have checked so far are removing the radiator cap = Bright Green fluid color
Started the Jeep = Zero Bubbles (head is fine)
Pressed Accelerator = sucked fluid level down and came back up when I let off the throttle (Guessing this says the Water pump is working)
Test spun the Fan clutch = barely moved after I let go (tells me the Fan Clutch is just fine)
Tested the coolant = Reads 268 Boiling point
https://cimg1.ibsrv.net/gimg/www.che...9eb865cac1.jpg

So at this point I'm at a loss.

Been an exhausting couple days and my mind is shot, any Suggestions would be much appreciated. At this point I think she will have to cancel Monday. :(

Been reading, checked the fan clutch when it was cold. Will warm it up and check again.

Is the radiator cap holdin the proper pressure?

Have not checked the cap pressure but decided to check the Thermostat. They had a 205 in it.

Betting it was not changed when the previous owners did the flush since the Right Hand Drive Jeeps have metal Power steering lines crossing in front of it making it hard to remove. I just removed the mount bolt and gently bent them up so I could get the the thermostat out and clean up the solid caked on gasket.

Plastic blade in my scrapper were not able to remove the gasket material so I changed the blade to a razor blade and gently removed the gasket making sure I kept the blade flat. All cleaned up with out maring anything and will be installing the new 195 thermostat after we get back from Easter lunch.

Swapped the Thermostat and just replaced the cap since it was $5. LOL

Drove it for 20 miles and traded with my wife so she could do another practice run for tomorrows big route. While I was driving it I was noticing the Jeep is running far cooler and current max temp is about the lowest it ever went with the other thermostat. Wife is still out so when she returns I'll let it cool off, then top of the coolant if needed.

Betting the Transmission will run even cooler now as well. LOL

You don't mention that the temperature was reading high as overheated. I'm guessing that heat soaking on the fuel injectors is turning the liquid gasoline into gaseous gasoline in one or more of the fuel injectors. The constant flow of liquid gasoline cools them and combats this. Letting the hot engine sit without cooling and restarting causes this experience. After a few minutes enough cool, liquid gasoline passes thru the injectors that the issue goes away.

This is my suspicion from your first post. You can swap the injectors, but I'd just cover the fuel injectors with heat shielding and possibly the air intake manifold as well. An alternative would be for her to just let it idle. I'm assuming that this vehicle is started in the morning and killed at night.