Replace The Thermostat Housing on a 2002 Ford Focus
This guide is about replacing a leaky thermostat housing on my 2002 Ford Focus ZX3 with a 2.0L engine, so it should apply to the various models using that engine (ZX5, ZX3, ZTW, ZTS, SE, LX and S2). I just happened to get a kit that includes the thermostat and outlet component at the same time. From my own experience and others I've read its quite common for the plastic thermostat housing to crack or break.
Please note I'm not a repair technician or a "car guy" at all. I'm just a guy on a budget who is driving my Focus till the wheels fall off, at which time I will write a guide on that.
- Water Temperature Gauge Warning
- Heat in the car does not work
- Burning or odd smell (Smelled like pancake syrup in my case)
- Puddle of Coolant (or Water) under car
Remove battery terminal connectors by loosening the bolts using a 10mm wrench or driver
Remove Battery Tray
Remove upper bolt with 13mm or 14mm Socket (This bolt may vary)
Remove lower bolts with 10mm socket
OPTIONAL: Remove Air Intake
Remove Screws with Phillips Screwdriver
You may need to gently twist the other end of the intake to slip it out of the air filter chamber. If the intake does not come out easily see how to remove the Air Filter Chamber in the next step, so you can pull the air intake hose out. (Don't worry its REALLY easy even for a novice like me.)
OPTIONAL: Remove Air Filter Chamber
Remove 4 screw holding on the lid of the Air Filter Chamber (or 3 screws in my case).
Remove Air Filter
Find Snaps underneath the Air Filter Chamber (2 on Left, 1 on Right)
Push up on snaps to release the Air Filter Chamber. Now you can easily remove the air intake hose.
OPTIONAL: Drain Coolant/Water
If you have a leak you can likely skip this step as you will have very little to drain.
If you suspect you still have coolant or water in your system you should place a drain pan beneath the Thermostat Housing to catch any coolant or water. You may also find a drain kit at your local auto parts store.
There are four hoses attached to the Thermostat Housing. Two front hoses (Red and Blue), a top hose (Green) and a rear house (not pictured). In the next few step we'll remove the three highlighted here. The forth hose (rear) will be removed once the Thermostat housing is loose from the engine block
Remove the top hose (green) first.
Remove the the two lower houses (Red & Blue). The hose clamp holding the hose may be difficult to release. If you have a clamp release tool this would be a good time to use it. Otherwise you can use pliers to remove it. A flathead screwdriver may help release them as well.
Remove Thermostat Housing
There are three bolts to remove to release the Thermostat Housing. Use a 10mm wrench to remove the top forward bolt (closest to you).
To Remove the top back bolt and bottom bolt you can use a 10mm deep socket driver.
Remove Thermostat Housing from Engine Block. You won't be able to take it out yet we still have one more hose to release. [pic is a overhead view]
Remove the final hose at the rear of the the thermostat housing. Again these clips are pretty tough to remove so don't worry its normal.
Remove Thermostat Housing
Clean Engine Block
Clean the area on the Engine Block where it meets the Thermostat Housing with Brake/Parts Cleaner or Water [pic is side view]
Install New Thermostate Housing
Position the new Thermostat Housing next to the engine block
Attach the rear hose we removed. You'll want to do this before you reattach the Thermostat Housing back to the engine block. The rear hose is pretty impossible to get to if the Thermostat Housing is installed.
Align the holes and insert bolts.
Hand tighten each bolt. Be sure to tighten evenly.
Tighten the bolts the rest of the way with the 10mm deep socket for the back bolt and the bottom bolt. You will need to use the 10mm wrench to tighten front bolt as it is too close to the metal line to fit the socket wrench.
Reattach the two front hoses and top hose.
Install Air intake and/or Air filter chamber. Just reverse the removal steps
Install battery tray and battery.
You're Done! That wasn't so hard. Now you can brag to your friends how much money you saved.