Introduction: Install Freeze Plug (a.k.a. Engine Block Heater) in a 2008 Scion XB

I live in Seattle, and that's where I usually drive my car, but soon I'll be visiting family around Edmonton, Alberta, where the winters are considerably colder. So cold that that Alberta cars usually have a special heater attached to their engines that runs off household 120 volt alternating current, not the 12 volt direct current of your car's electrical system. At certain times, you plug this car engine heater into your house's electrical system.

This is usually called a block heater. Toyota calls it a freeze plug.

Why does this matter?

If your engine block is warm, the oil in the engine stays liquid/high viscosity, instead of becoming hard or even almost solid if the engine and oil in it were, say, twenty degrees below freezing. Warm, highly viscous engine oil makes it much easier to start your car in very cold weather.

You've heard the expression, When in Rome, do as the Romans do.,
right? When driving in Edmonton, do as the Edmonton drivers do. Plug your car in, if it gets really cold outside and your car's engine is going to cool down to the very cold ambient air temperature.

I have a 2008 Scion xB with a 2.4 liter 2AZ-FE engine, which also happens to be installed in some other Toyota vehicles, including the base model of Camry for the same year.

I got the freeze plug from my Toyota dealership. It is made by Zerostart. The application guide and product catalog is available from Zerostart, a unit of Philips and Temro. I tried to provide a link to the .pdf but it seems Instructables.com won't let me.

PS. As regards the structure of this Instructable, I basically plagiarized the instructions written by someone on a Scionlife forum, written for a different vehicle. I followed that procedure as best as I could on my later model xB, and took a few photos. I hope the result is not too confusing and makes sense.

Step 1: Read the Application Guide and Product Catalog (but With a Tiny Wee Grain of Salt).

The 2AZ-FE 2.4 liter engine is transverse mounted in my Scion xB. Therefore, look at the transverse diagram to see where the freeze plug is supposed to be placed on my engine. I say supposed because that's not actually where the plug goes on my car/engine.


Philips and Temro/Zerostart/Toyota, this is where your instructions start to go wrong, or just plain don't exist. Notice how the diagram says LR, and what LR points to on the right hand engine image? That's where the application guide says my block heater is supposed to go.

No! The hole is not there! It's where I marked it, "here" (see the first picture).

Please, Toyota/Scion/Philips and Temro, edit your guide! It's incorrect.

Step 2: Follow the Instructions Quoted Here, As If for a 1.8l Pre-2008 Scion XB

I found out how to do the installation on the prior year model of xB, which takes the same block heater part number, even though pre-08 xBs have a 1.8 liter engine. Mine is 2.4 liters (2008 and later xBs).

Basically the procedure is similar on the 08 xB. I will reproduce it here inline, but beware, this is for a different vehicle:

DIY: xB block heater install

As with all the DIY’s on ScionLife…if you mess your car up it is YOUR fault. This is only meant as a guide and a help and if you cannot take it as such…take your car to the dealer.

Time to install: 45 minutes - 1 hour, 15 minutes.

Tools / Supplies Needed:

-Ratchet set with 10mm socket

-the longest extension you have

-large flat-blade screwdriver

-small mirror (makeup mirror or similar size)

-latex gloves (useful, but not mandatory)

-shoplight / flashlight

-handful of wire ties

-wire loom

-automotive double-sided foam tape

Just for reference, here is Toyota's install guide.

1) Get the right part. It is Toyota part #00213-00885. There are other block heaters from Toyota that look like they will fit and may even be labeled to fit the 1NZ-FE engine, but this is DEFINITIVELY the right part for a generation 1 Scion xB (3 hours wrestling with the wrong part to back me up). I got it from Ressler Toyota in Bozeman, MT for approximately $48.

In the box you will see the block heater element (metal tube with a clip and electrical hookup on one end), the electrical cord which plugs into the heater element, a plug cover for the cord, some silicon grease to aid in transferring heat to the block, and a handful of wire ties.

2) Before you get going, you need to know where the block heater is installed. There is a machined hole specifically for the block heater on the back of the block (driver’s side of the engine), close to the firewall, about halfway down on the block. It is my understanding that this is on every 1NZ-FE engine, not just those in Canada, sold in the northern US, etc (I got my xB in California).

To find this hole, reach behind the engine (towards the firewall) over the engine cover (from passenger side to driver’s side) and feel around. It is right on the firewall side of the block about halfway down. The hole is about as large as your index finger and is approximately three to four inches deep.

Once you have found this hole, take an air gun and blow it out to get dirt, etc. cleaned out.

3) Remove the engine cover. There are four bolts which have 10mm heads.

3a) Here is an overview for the next few steps

4) Remove the two electrical connections to the airbox / air outlet tube. They are simple clips that remove when you push on the release button. Be careful, as these wires are fragile and a hassle to replace.

5) Remove the clip holding the wire bundle to the airbox.

6) Remove the clip holding this hose to the airbox. Gently work it up and off. If the clip is bent slightly in the process, make sure to bend it back so it holds securely when replacing.

7) Remove the PCV tube from the air outlet tube.

8) Remove the air outlet tube from the airbox cover by loosening the large screw on the clamp and wiggling the tube off the airbox cover.

9) Unlatch the airbox cover and remove it.

10) Remove the air filter. This is a great time to replace it with a K&N or similar if it’s dirty.

11) Remove the three screws at the bottom of the lower half of the airbox. I believe they are 10mm bolts. This is where the long extension comes in handy.

12) Remove the air inlet tube from the grill-side of the lower airbox. This is accomplished by twisting it back and forth and applying steady pressure. It’s a little stiff the first time you remove it…

13) Remove the lower half of the airbox. You now have some room to work with!

14) Use your mirror to “see” the machined hole where the block heater installs. It’s best viewed if you place the mirror on top of the transmission facing the back of the block. A light of some sort is very helpful.

--Changing gears, now we are working with the heater element and the electrical cord you got from Toyota.--

15) As I am very picky about things, I added some wire loom to the electrical cord all the way to the plug…I am sure it’s not necessary but I thought it looked more put together.

16) The block heater element will slide into the block with the blank end facing the passenger side of the car and the end with the electrical connections facing the driver’s side. The clip will be aimed towards the firewall in the 2 o’clock position. With this is mind practice plugging in the electrical connection and visualize the way it will fit before you install the heater element in the block. It will be much trickier then. Hint: the electrical cord will initially be aimed at the firewall…

17) Take the block heater element and smear the silicone grease all over the metal part of the element. DO NOT GET ANY ON THE ELECTRICAL CONNECTORS OR NEAR THE CONNECTION END. (This is where you want to use the gloves).

--And back to the engine.--

18) Smear the same silicone grease inside the machined hole where the heating element will mount. Try not to get this all over everything else in the process. The grease aids in transferring heat from the element to the block.

19) Insert the heating element into the machined hole, orienting the clip toward the firewall. It should slide smoothly into the hole. Push it in until you hear a solid ‘click’ from the clip. It clips onto a ridge in the block to prevent movement.

20) Connect the electrical cord like you practiced. A little harder now, eh?

21) Route the cord along the existing wire bundle towards the front of the engine. Use the wire ties as you go. Continue wire tying the electrical cord to the wire bundle along the engine block just in front of (towards the grill) of the spark plugs.

22) When you reach the front of the block (passenger side), route the electrical cord forward toward the grill.

23) If you are running a stock grill, the cutouts are perfectly shaped to hold and somewhat hide the plug.

(If you don’t have fog lights, pop out the fog light knockout by pushing it out from the engine bay. You can then get a hand in there to help hold things in place.)

Push the plug cover through one of the spaces in the grill first. Then follow with the plug itself. It should be snug in the grill, but not so tight as to feel like something will break. Ensure that there is a suitable amount of slack in the electrical cord.

24) Use double sided tape to secure the plug in the cutout in the grill.

25) Make sure that everything is wire tied appropriately and that the electrical cord is not in a place where it will be pinched, cut or rubbed and that it will not interfere with any moving parts, etc. in the engine component.

26) Replace the engine cover.

27) Replace the lower half of the airbox, three mounting screws and air inlet hose.

28) Replace the air filter and upper half of airbox.

29) Replace air outlet hose, PCV hose and all electrical connections.

30) Enjoy a nice warm block, better gas mileage and easier cold weather starts.

If you have any questions, please PM me. I am sorry I didn't have any pictures of the parts themselves...I had already installed it when these pictures were taken. Thanks.

Last edited by bigskyscion; 11-04-2010 at 07:51 AM.

Step 3: Find the Socket That the Cartridge Will Snap Into.

Blow the socket out with compressed air and smear the cartridge and opening with the silicon grease (next pic).

Step 4: Smear Grease on the Cartridge and Inside of the Cleaned Socket on the Engine. Plug the Cartridge In.

Push the cartridge into the hole and make sure the clip catches.

Step 5: Plug the 120 VAC Electrical Cord (female End) Onto the Male Contacts on the Cartridge.

When the line voltage cord is attached to the cartridge, route the cord alongside the wire harness that's under the engine cover (you will have to remove the engine cover to do this). Use wire zip ties. When the AC cord is routed correctly, replace the engine cover. Route the rest of the line voltage cord and secure with ties.

You should end up with just enough cord protruding from the grille to be able to plug your car in without opening the hood.