I see A LOT of people are not installing the housing and filling it up correctly. To properly do the job, remove your old housing and clean the metal flange where the new housing will go. You can use gasket seal on here once it’s clean, which will help better seal up this “common leak area”.
Now install the new housing and tighten up each of the 3 long bolts a little at a time until all 3 are snug. Now that the housing is nice and tight, unscrew the 3 (new) small bolts on the thermostat portion. Remove the cover and take out the new thermostat and it’s o-ring, making sure that you remember the positioning of this thermostat!
This is where you then take a new jug of antifreeze and fill up the engine portion. With the thermostat removed, pour in some coolant until the coolant level rises to the thermostat. This process allows the air to escape as you fill the internal engine portion. Now insert the thermostat and wet the big o-ring and firmly set it in place with no kinks. Re-install the thermostat cover and tighten the new screws evenly one by one. Attach your hose to the thermostat cover and fill it up with antifreeze and attach other end to radiator. Now fill radiator to the top and install radiator cap. Squeeze the hose a few times... Start with a slow squeezes, remove radiator cap and top off. Squeeze hose again, but this time do a few fast squeezes (but not too hard). Top off again if possible.
Start the car and let it idle until it starts to get worm. Go inside and check for heat at dash, and watch until temp gauge starts to rise. Is there heat at dash yet? No. Then keep burping the system, but this time burp the smaller hoses that connect to the thermostat housing.
If done correctly, with patience, everything will work out fine. Never go for a test drive right away. Always let a cold engine heat up to normal operation temp on its own first. Leaks start off small at first, but usually don’t show until the engine temp reaches normal.
If you catch the leak before it starts, you will still be in your driveway and not 10/30 miles away.
I rate this product 4 starts, but I should probably be giving it just 3. The housing is not the same as the OEM (as you could expect). The opening for a 2nd temperature sensor is always knocked out from the factory- which I absolutely HATE. The factory installs a plug in this 2nd hole instead of leaking it sealed the the Motorcraft version. This plug gives the unit an “opportunity” to leak for no real reason. Also, the plug comes with an attachment clip, but they don’t give you a clip for your new or existing temperature sensor.
Additionally, if you DO purchase a new temperature sensor from duralast.. that temperature sensor doesn’t come with an attachment clip either. Luckily I was able to use my old rusty one, but not sure what would happen if I misplaced it or mine ended up getting damaged. Beware!
Before purchasing a Thermostat, make sure it’s the right one for your vehicle. Every engine is different, and every engine needs a specific thermostat. Thermostats all have a special temperature rating, so reviewers saying the thermostat wouldn’t open up at 180/190 could possibly even have the wrong thermostat.
Thermostats don’t open up to let hot coolant into radiator if there is air pockets inside the engine bay. Properly filling up antifreeze as you connect pieces, helps to make sure no air pockets exist. :)
What kind of vehicle do you drive? 2008 Ford Explorer