Engine Block Heater Installation on 5th Gen 4Runner

ENGINE BLOCK HEATER AND TESTING

If you live in a very cold climate it may be a good idea to install an engine block heater. Here in the Colorado Rocky Mountains, it’s not unusual to see -25°F in the middle of the winter. It will help the oil flow more easily during start-up preventing any possible oil starvation issues.

The block heater also helps to keep the whole engine bay warmer and as a result of the battery slightly warmer as well, preventing a large voltage drop at very cold temps.

The block heater pulls 400W, about ¼ of a typical space heater, so you shouldn’t expect a large increase in your electric bill unless you use it all the time. You can also get an outlet timer to further help reduce your electricity usage.

There are a few styles of block heaters. Many require you to drain the coolant or pop out a freeze plug. Luckily, Toyota designed the engine block to have a hole drilled into the engine block so that all you must do is insert a heater cartridge into the hole.

I found a few people in the forums that said they had installed it themselves, but I could not find any photos of where the port in the block is.

In this guide, I’ll show you exactly where it is and how to install it.

Parts and Tools:

• Block heater: Check Today’s Price
• Silicone Heat Sink Compound: Check Today’s Price
• Dielectric Grease: Check Today’s Price
• Telescoping Magnetic Grabber or Similar: Check today’s price

LOCATE THE HOLE IN THE ENGINE BLOCK:

The hole in the engine block is at the back of the engine, next to the transmission. It is tricky to get to, but not impossible and the install doesn’t require removal of any components.

You will want to get the car up on jack stands or ramps.

Here you can see what the hole looks like from below the car. You don’t need to remove any of the skid plates unless you have a larger aftermarket skid plate installed.

Find the driver’s side exhaust and you should be able to see the hole to the right of it.

PREPARE THE ENGINE BLOCK HEATER:

Using some gloves, apply the silicone heat sink compound to the block heater. This allows the heat to flow effectively into the engine block.

The easiest way to get the block heater into place is to attach it to a rod to get it lined up. I used a telescoping magnetic grabber and then used some tape to hole it in place.

INSERT THE ENGINE BLOCK HEATER:

Use the rod to slide the block heater into place. Once the heater is as far in as you can get it with the rod, pull on the rod to release the tape.

CLIP IN THE ENGINE BLOCK HEATER:

Finally, push the heater the rest of the way in by hand. There is a clip on the heater that will slid over a bump on the left side of the hole. That will clip the heater in and hold it in place.

LINE UP THE POWER CORD:

Drop the electrical cord down the back of the engine. If you drop it down the same location as shown in the photo it should end up next to the block heater.

PLUG IN THE BLOCK HEATER:

At this point you should be able to insert the orange end of the cable into the block heater. There is no polarity requirement.

ZIP TIE THE POWER CABLE

Ziptie the power cable to the grey wire harness that runs along the back of the engine bay. Place the first ziptie directly above the block heater. This should keep the wire away from any hot or moving parts.

ATTACH THE REST OF THE POWER CABLE

You have a few options here.

I chose to run the power cable to the driver’s side of the engine bay and attach it near the ABS module. Zip tie the power cable to the grey wiring harness and then zip tie the end to the bracket near the ABS module.

PERFORMANCE

I parked the car outside and measured the outside air temp as well as the coolant temp just prior to starting the engine. On the first day I did not plug in the block heater.

It was 3°F and the coolant temp read 12°F. On the second day, I plugged in the block heater for the full night. I measured 19°F outside and 69°F on the coolant temp sensor.

I definitely noticed that the engine started up with substantially less resistance. I also didn’t hear the air injector whine, while it did the day before.

The cabin temp definitely heated up faster as well.