Unexplained High Temp reading

[DFendersExpy]

I posted this in the wrong Generations:


OK now its happening again ...Last several days I will drive for a bit not long just around town, I'll shut it off for like 15-25 mins go to start it up and that high temp reading all over again. But if I shut it off then turn it back on its back to normal ... What the heck can be wrong.... Coolant level is fine . I check what i could on the grounding looks ok I even Added a 0 gauge wire for grounding to the body for added measure from the battery.. I dont have the means to check or even remove the CHT sensor... I was wondering can I bypass it somehow... Maybe unplug the CHT sensor and Plug it to a new one without taking apart the intake to get to it? Can this be done? As much as I love Expeditions and Ford for that matter this one has been a nightmare since i purchased it a month ago... I'm not giving up on it yet... HELPPPPPPPPPP!!!!!!!!!

 

[FordandPolaris]

Any check engine light codes?

 

[stamp11127]

Depends on what tools you have and what you can eliminate.

First thing I would do is park on an incline and burp the cooling system to make sure there isn't a bubble hiding in there.

Second check the connection for the sensor - clean and tight is right.

Third is an unofficial fix - smack the dash above the gauge while it is reading high and see if it changes.

 

[DFendersExpy]

Any check engine light codes?

yes I had a P1299 It hasent come back up since I just turn the key to on let the high temp go up then back off. After that I can turn the truck back on normally with no high temp reading.... But I dont want to do this all the time

 

[DFendersExpy]

Depends on what tools you have and what you can eliminate.

First thing I would do is park on an incline and burp the cooling system to make sure there isn't a bubble hiding in there.

Second check the connection for the sensor - clean and tight is right.

Third is an unofficial fix - smack the dash above the gauge while it is reading high and see if it changes.

Forth Light a match....Just kidding

 

[FordandPolaris]

I would not bypass the sensor personally. It's there to protect against severe engine damage. I found a picture of the location of the sensor, if you pull the alternator (3 bolts and a plug on my truck) you should easily be able to reach it. How come you feel you don't have the means to replace it? It appears that it just threads in and they are only about 15 bucks online.

 

[DFendersExpy]

I would not bypass the sensor personally. It's there to protect against severe engine damage. I found a picture of the location of the sensor, if you pull the alternator (3 bolts and a plug on my truck) you should easily be able to reach it. How come you feel you don't have the means to replace it? It appears that it just threads in and they are only about 15 bucks online.

From what I have read before you would have to remove the intake manifold
Thats what i was referring too...

 

[DFendersExpy]

Well I've been managing with this High temp reading on and off for a bit now... turning it on then off then back on to get a normal reading. So as of yesterday I've got a cold temp reading even after driving for a bit. now check engine light is on and the truck just went into limp mode ...getting a P1290 and a P1299.....

 

[splintrcel]

It could be the thermostat. When it goes bad it causes all sorts of wierd readings. my 2006 honda pilot is doing something similiar where it gives all sorts of readings and lately its been pushing high temps. Its like a $15 part and comes out in like 15 min. You just have to dump some coolant to get it out unless you feel like dumping coolant all over the oversensitive coil packs.

 

[Hamfisted]

Those are bad signal from temp probe codes. Take a mirror tool and look at the sensor and see if the wires are damaged or you just need a new sensor all together. Sometimes goofy stuff like rodents up under the hood will damage the wiring.


-Mike

 

[DFendersExpy]

Those are bad signal from temp probe codes. Take a mirror tool and look at the sensor and see if the wires are damaged or you just need a new sensor all together. Sometimes goofy stuff like rodents up under the hood will damage the wiring.


-Mike

Hard to see under the manifold......

 

[metaldrgn]

I suggest changing the cht sensor. Looks like it's a known issue. With that 1290 fault it definitely looks like an electrical problem and coolant temp is fine. Check all the wiring and the pins while you are in there too. Maybe put some dielectric grease on the contacts but make sure the grease doesn't short out the terminals.

 

[mindgame]

fan clutch?

 

[stamp11127]

Hmmm, how is a product that is designed to prevent voltage leaks going to short out the connections?

 

[metaldrgn]

Hmmm, how is a product that is designed to prevent voltage leaks going to short out the connections?

I thought the grease was electrically conductive but after looking it up it isn't so disregard that last bit ; ). Still use it though

 

[keithnra]

Depends on what tools you have and what you can eliminate.

First thing I would do is park on an incline and burp the cooling system to make sure there isn't a bubble hiding in there.

Second check the connection for the sensor - clean and tight is right.

Third is an unofficial fix - smack the dash above the gauge while it is reading high and see if it changes.

this is some good advice especially the last one

 

[metaldrgn]

Depends on what tools you have and what you can eliminate.

First thing I would do is park on an incline and burp the cooling system to make sure there isn't a bubble hiding in there.

Second check the connection for the sensor - clean and tight is right.

Third is an unofficial fix - smack the dash above the gauge while it is reading high and see if it changes.

First - it doesn't sound like an actual overheating problem. A bubble isn't going to make it just up and reset when you restarts the car.

second - is a good idea

Third - while you have a slim chance of something actually changing by smacking the dash, you can also shake the wiring by the connectors to get a better idea if you have a bad/loose connection.

 

[DFendersExpy]

Well the mystery has been solved.... CHT sensor needs to be replaced along with the intake manifold gasket needs replacement..... After passing out from what the dealership is charging me to have this done , I have no choice but to get it done.... These are the times I wish I had my own shop so I can get this done on my own... Had a friend who said he would do it for me but stood me up several times... Can't afford to keep missing work over this....... Oh well
Time to sell My paintball gear and anything else I can get rid of...

 

[metaldrgn]

If you were closer I'd help ya

 

[DFendersExpy]

If you were closer I'd help ya

Thanks Brother i wish you did too....

Dealer called earlier today to give me more wonderful news.. Cracked intake manifold...Just another $500 to the bill.... WOOHOO

I LOVE MY EXPY , I LOVE MY EXPY, I LOVE MY EXPY......