Episode 34 - Replacing Thermostat 2010 Ford Fusion 

Good to know. Thanks for the info.

2010 Fusion is a pretty decent sedan for its time. Good power, decent fuel economy, decent cabin and trunk size. Does his have the 2.5L or 3.0L?

@@MazdaB3K 2.5

That is a slightly underpowered but very reliable engine. I had the same one in my 2016 Transit Connect. Make sure you do the fluids as needed and that engine will last about forever. One thing I did forget to mention. The 2010 Fusion has the 6F35 transmission which is decent as long as you do a drain and fill on the transmission about every 30k miles. I do have a video up under the 2010 Fusion playlist that covers how to do this. Make sure you use Mercon LV compatible fluid.

A wise plan on a daily driver. Thermostats generally are going to be located where block meets radiator hose, generally on the return side of things. I'm glad my video helped!

Glad it helped.

Happy to help! Thermostats generally aren't too hard and it's good to know about them as a car gets older. A stuck thermostat can equal a very bad day.

Thanks for the sub! Good luck on the water pump. 2020 means that should be an ecoboost engine. Not sure how the water pump is setup on those.

Try 2010, since 2011 was the last model year for Mercury.

@@bobbyheffley4955 I'm bad, I meant 2010. Thanks for correcting me..

Glad you were able to solve your issue. And you are correct, it should only go one way...

Thanks! This is one of my more popular videos.

Glad it was helpful!

In a perfect world you would use a thread chaser and a die to clean up the plug and the hole it goes in...In the real world it doesn't matter. Since the bleeder is pretty accessible I didn't even put a new application of any kind of threadlocker on it.

Between #2 and #3 spark plugs...Under that rubber grommet

Happy to help!

Providing you installed a good thermostat, spring side towards the block and did indeed bleed all the air out of the system, you need to start checking the other parts of your cooling system. Are the fans kicking on at around 223F? Do you have obstructions in your cooling passages? Is oil getting into coolant and reducing cooling effectiveness? Is the radiator clogged? Is the cooling system staying under the correct pressure? It should be running under 16lbs of pressure so checking the cap on the overflow tank for good seal is important as well. Those are the places I would start.

I have another video that deals with a part I call a fan controller than can go bad and will cause the fans not to kick on. In the short term run your AC. That should cause the fans to run for the AC which should help with cooling until you solve this issue. On my channel page, click the 2010 Ford Fusion playlist and it should have the fan controller video in it.

Nope. I said that because the thermostat is located above the transmission housing and in the process of getting to the thermostat I very thoroughly doused the transmission housing with coolant. It's sealed so no worry for damage there either.

Since I replaced the fan controller in mine, I've had zero issues with the cooling system. If you are having issues with the cooling under load I would check the status of your coolant, check to see if your thermostat is good and check to see if your fans are spinning up when they are supposed to.

Some other possibilities are a clogged radiator or a bad pressure cap on the overflow tank. From the other comment you left though it sounds like you had dirty coolant.

You should not need to take off any belts going after the thermostat. A bungee strap is handy to hold the radiator hose out of the way so that you can get access to the water neck where the thermostat is located.

You might of been watching something regarding the water pump instead of the coolant thermostat.

That was a video of the 2.5 liter engine with an integral housing. The 3.0 liter is easier.

The trim on my fusion is a SE. The L in SEL though means Leather package, so I imagine the engine is the same.

I do not. The 3.6 is a Duratec engine, same family as the 3.0 I have. But I do not know if they moved stuff around to squeeze in the extra .5 liter. A good way to check for the thermostat is trace the upper rad hose back to where it meets the block and look for a water neck there. Normally thermostats live in that area. The very best bet would be to grab a Hayes or Chilton manual and look up the procedure for the thermostat for your engine.

OEM spec, 180F (82C)

Let's dig into this a little bit. Car is running hot. So far you have: 1. Replaced the radiator 2. Replaced the pressure cap on the overflow tank 3. Replaced the water pump belt 4. Replaced the water pump 5. Did an exhaust gas test on the coolant, came back clean 6. Did a pressure test on the cooling system with the new cap, pressure came back good 7. Replaced the thermostat With all those parts replaced and tests done, you still notice: 1. When accelerating or placing the engine under heavier loads the temp gauge spikes. You've done most of the tests that I would do to make sure the cooling system is behaving correctly. Since I didn't see the work done, I would check to make sure the gasket on the thermostat is in place, and the thermostat has been placed in the correct orientation (spring side towards the block). The fact the car is spiking in temp under heavier loads, then calming down under lighter loads says the cooling system is working to some degree. I don't think you have an air bubble in your cooling as that would cause random temp spikes as the bubble is circulated around the cooling system. Another possibility is that the cooling temp sender might be dying. That is the sensor that supplies temp data to the instrument cluster. I don't really think this is the issue, but it's worth checking out. I would also check the status of any cooling hoses, making sure they are not collapsing under heavier loads. I've never seen that happen, but I do know that formed hoses will lose the ability to keep their shape as they get towards the end of their life. I know your hydrocarbon in coolant test came back clean, but I would also check your oil for milkshake, just to be sure. Pull the oil dipstick and look for a frothy, chocolately brown color. If you see that it means moisture is getting in the oil. A little moisture is normal around the oil cap particularly if it's humid weather and the engine hasn't been ran at operating temp for a bit before being turned back off (~30 minutes). If you still see chocolate goodness after that, might have some exchange going on. Beyond that I can't really think of anything that you should check, other than double checking the installation of all the parts you've swapped. Good Luck!

@@MazdaB3K It's more noticeable after I change the radiator yesterday

I figured out the issue the brand new failsafe thermostat I purchase from napa auto parts was defective and I determined this because when the car was overheating yesterday the lower hose was not hot but the upper one was scorching

Fantastic! I'm glad to see your troubleshooting paid off! It's rare, but sometimes new parts do fail off the bat. The part houses figured out awhile ago it's cheaper to offer warranties than it is to actually test the parts. Motorcraft is the only exception that I know to this, which is partly why their stuff is always so expensive. Again, nice solve.

These videos are geared for beginners to car repair and maintenance. If I'm not moving to your pace, no one is stopping you from fast forwarding through the video to get to what you need.

What exactly do you need help with?