Happy Sunday, all.

I have a 2005 Expedition with 315,000 miles. It is throwing a P1289 code, cylinder head temperature sensor fault. The engine temp gauge on the dashboard stopped reading also, it doesn’t show any heat even after running. Is an inspection of the CHT wiring and replacing the sensor the first step? If so, anyone have a guide for replacement and location for the sensor? I’ve searched the forum, but it seems I find different locations for F150, earlier Expedition, etc. it looks like I may need to remove the exhaust manifold. Before I dive in, it would be great to hear from someone who has done this. Thanks!

 

Here's a good video on the job on the 3V motor. Autozone has them in stock (made in Mexico). The Motocraft one I got from the local Ford dealer was made in China.
A flex head ratcheting box wrench will come in real handy for this job. Both GearWrench and TekTon are made in Taiwan, but good quality tools.

Gearwrench Xtra Long Flex Head Ratcheting Metric Wrench Set on Amazon

Gearwrench Xtra Long Flex Head Ratcheting Metric Wrench Set on Amazon

Craftsman Flex Head Ratcheting Wrench Set Metric - Made in USA - Ebay Used

 

Many thanks! I’ll have to let the wife know that it would be a shame to let that 19mm flex head ratchet sit all by itself without a set to go with it.

 

I just replaced that sensor on a 00 expedition, it was really easy. It was located on the drivers side under the intake manifold about 3 inches back from the front. Easy to replace, pull the alternator bolts and move it to the side(I didn't have to remove mine), should have enough room to reach in unplug the sensor. If you have a short 3/4 wrench you can use that to break it loose.(I had a short wrench so I'm not sure if a regular wrench will have enough room to use). Remove sensor install new one, plug wiring back in, reinstall alternator...done.

 

If you google this, it'll help you out..apparently your sensor is on the passenger side, in the middle of the block.

Just seen this, apparently your sensor is on the passenger side, in the middle of the block. Also if you have a swivel head ratchet wrench that will work, if not he shows what he did..cut a double box end. Best of luck.

 

Thanks, Bgood.

I had seen the location on some like your 00 Expedition and on the F150 i think it may be different too. I will take off the alternator once my part arrives. I ordered the sensor and the flex ratchet wrench. I’ll see how far I get this weekend. Always great to get the quick responses!

 

Hi again.

The video you shared is right where I need to get, but I ran into a plastic and hard foam piece where I need access. The piece is old and brittle and if I force it I think it will break.

What is is? And can I just yank it out without doing lasting damage. See the pic for what I mean. Thanks for any advice you have.

 

I'm necro'ing this thread because I just did an '06 and ran into the same stupid insulation as shown. If you look further back it's actually 2 pieces and connected with Christmas tree clips, pretty much right at the CHT in the RH (passenger) head. Some creative pry bar work will get it to pop apart. I did not reinstall, our '08 F150 with the same engine has never had this as long as we've owned it from 89k miles to 140k miles.



Also, just a tip for others: to get the electrical connector off I used two pry bars strategically placed: one to gently lift, and one to disengage the tab. The tip is this: the connector is disengaged near it's base, furthest from the wires. With many connectors you disengage by squeezing at the "top," near the wires, but this one is a little different.

Finally, I had a Williams reversible flex ratcheting wrench and the reversing mechanism makes the head too big and too long. You do indeed need a basic, non-reversible (this means you flip it over to go the other direction) ratcheting wrench.