Diesel heater installation

[4RExplorer]

I'd like to install a 2kW diesel heater inside my 4Runner, for overnight heat on cold days. I'm having some difficulty finding a place to install it. Has anyone successfully done this before, and if so, where did you install yours?

Right now, I am thinking of routing the combustion exhaust tube through a hole to be drilled in the floor of the cargo area somewhere, to end just below the rear edge of the rear bumper. But I'd be interested in how others have done it.

 

[Oogs]

Why not go gas and just tap into the existing tank, Unless you already have the diesel heater? I had an Espar and it was great and sipped fuel but that rig was diesel.

 

[4RExplorer]

Why not go gas and just tap into the existing tank, Unless you already have the diesel heater? I had an Espar and it was great and sipped fuel but that rig was diesel.

That's an idea, but I already have the diesel heater. My main difficulty is finding a spot to punch the hole in the floor for the exhaust tube. Maybe it all just works though if it goes through the rear corner, either on the driver's side or the passenger side.

 

[jdm-v35]

I would not ever want it mounted inside. I use one for camping but just feed the hose into RTT. Even leaving the heater in front of the car the fuel pump ticking is annoying and sometimes you can smell a bit of fumes. The fuel tank also needs to breathe so youll smell the fuel if youre close to it.

 

[4RExplorer]

I would not ever want it mounted inside. I use one for camping but just feed the hose into RTT. Even leaving the heater in front of the car the fuel pump ticking is annoying and sometimes you can smell a bit of fumes. The fuel tank also needs to breathe so youll smell the fuel if youre close to it.

The ticking noise was one reason I didn't want a diesel heater a few years ago when I was looking for a way to heat the inside of the vehicle (I sleep there instead of in a RTT). But this year, I found out about a silent fuel pump invented by a guy named James Browning-Smith. Apparently it uses a different mechanism altogether to pump the fuel. 8:20 of the YouTube video "Quiet diesel heater pump. Invented and built by a British enthusiast." shows the pump really is silent.

The 5.5 liter plastic fuel tank I got has a little hole in the cap which lets diesel fumes out. Smelling diesel fumes when the heater is running would be a dealbreaker for me. So I'm thinking of using a beefier gas can, like the No-Spill 2.5 gallon gas can, which doesn't have a vent that is permanently open. Then, to let it breathe, I would install a two-way breather valve to relieve pressure inside when driving up mountains, but also act as a vacuum valve and let air in while the heater is running. Maybe this would get rid of the diesel smell during heater operation.

 

[jdm-v35]

The ticking noise was one reason I didn't want a diesel heater a few years ago when I was looking for a way to heat the inside of the vehicle (I sleep there instead of in a RTT). But this year, I found out about a silent fuel pump invented by a guy named James Browning-Smith. Apparently it uses a different mechanism altogether to pump the fuel. 8:20 of the YouTube video "Quiet diesel heater pump. Invented and built by a British enthusiast." shows the pump really is silent.

The 5.5 liter plastic fuel tank I got has a little hole in the cap which lets diesel fumes out. Smelling diesel fumes when the heater is running would be a dealbreaker for me. So I'm thinking of using a beefier gas can, like the No-Spill 2.5 gallon gas can, which doesn't have a vent that is permanently open. Then, to let it breathe, I would install a two-way breather valve to relieve pressure inside when driving up mountains, but also act as a vacuum valve and let air in while the heater is running. Maybe this would get rid of the diesel smell during heater operation.

If I am camping alone I sleep in the back too but I just use a -25 bag. I have camped in the back numerous times when it actually was -25 and I was fine. I did see that quiet pump but it costs as much as the heater.

 

[4RExplorer]

Yes, I have a 0 degree sleeping bag, works well. Wool cap or balaclava, wool socks, underlayer, etc. The diesel heater has some advantages though since it heats the air.

 

[4RExplorer]

At 8:15 of this video:

Living in my 4Runner | SUV Final Buildout | Carpentry + Diesel Heater + LiFePO4 Battery Install PT.2 - YouTube

it looks like the hole in the floor for the exhaust pipe is in the 2nd row, near the driver's side door, in a 2014 4Runner.

 

[4RExplorer]

Installation location of 12V diesel heater

I picked a location to install the 12V diesel heater: on the 4Runner sheet metal floor, in the rear passenger side corner, between the wheel well and the rear hatch.

Photos show the top view; the side view; and the view from under the vehicle. In the photo from under the vehicle, the 3 long bolts hold the heater mounting plate to the floor.

I had to trim the mounting plate that comes with the heater to fit the space available. Before and after shown.

Originally, I was going to drill separate holes in the floor for the combustion exhaust pipe, the combustion air intake pipe, the fuel line, the four bolts that attach the heater to its mounting plate, and the four bolts that attach the mounting plate to the 4Runner floor. But after trimming the mounting plate to size, I ended up drilling just three holes to attach the mounting plate to the floor, and then I cut two large holes for everything else. (The small, 1-gallon diesel tank will be inside the vehicle, so I still need to drill a hole nearby so the fuel line can be routed from the diesel tank to the underside of the heater unit, where it enters the combustion chamber).

The combustion exhaust pipe will come straight down from the heater unit, then bend almost 90 degrees rearward, ending about where the 4Runner exhaust pipe ends, but outboard of that pipe.

 

[4RExplorer]

Spacer Under the Heater Unit

One of the photos shows a large rubber grommet and wire loom going through the floor, pretty close to the hot combustion exhaust pipe. The grommet almost touches the outside case of the heater unit; I can just slip an index card in between. I wanted more space so that I could insert a piece of heat shield material in between, to protect the grommet and wire loom from the hot end of the heater unit. But I didn't want to move the Toyota OEM wiring, so I ordered four more mounting plates (from a different manufacturer) and trimmed them to size. Stacking these four extra mounting plates on top of the original one will raise the heater unit by maybe 1/4", allowing me to slip a piece of heat shield in the gap.

I will install with Permatex Ultra Black Gasket Maker Oil Resistant 75190 below each of these five plates.

 

[jdm-v35]

Pretty cool and I am curious to see the final results. I am guessing the rear floor area is stripped out for a platform so you are able to fit this under it?

 

[4RExplorer]

Pretty cool and I am curious to see the final results. I am guessing the rear floor area is stripped out for a platform so you are able to fit this under it?

Thanks, yes, on both the driver's side and the passenger side of the cargo area, I removed the lower trim (which covers the wheel wells). I also removed the OEM carpet from the cargo area floor. But I kept the white Styrofoam panel underneath the carpet. Then I put on a rectangular piece of 3/4" plywood on top of the Styrofoam, to make a floor. That plywood floor is 43 3/8" wide, so it covers basically from one rear wheel well to the other.

This location for the diesel heater is just outboard of that plywood floor. So it won't interfere with whatever is on the floor.

A lot of people build a raised sleeping platform with drawers underneath for storage. If I had such a platform, the heater would be positioned below the sleeping surface. But I decided instead to put my sleeping pad directly on the plywood floor, so that I can sit up at night. For storage, since I don't have drawers under the sleeping platform, I built a shelf system that goes over the cargo area. The shelf is roughly 34" front-to-back (it goes almost all the way to the rear hatch), and 48" side to side, and is positioned about 19" above the plywood floor. The 19" is enough for me not to hit my knees on the front edge of the shelf when I bend my knees while lying in my sleeping bag. So while driving, I store stuff on the floor, since anything on the shelf would block my vision through the rear view mirror. Then, before going to bed at night, I move stuff from the floor to the top of the shelf (and maybe to the front seats, if there is too much stuff), to make room for my sleeping bag.

 

[4RExplorer]

Hanging the Combustion Exhaust Pipe

To support the combustion exhaust pipe, I am using two holes that I found just above and inboard of the end of the 4Runner exhaust pipe. These holes are next to a round thing which I think is a body mount. I made a bracket from 1 1/2" x 2" x 1/8" angle iron, drilling four holes into it and cutting a curve into one edge using a jigsaw, then painted it with grey Rustoleum. I bolted this DIY bracket to those two holes with M8 bolts.

I couldn't fit my fingers or a wrench above those two holes to hold the nut in place when trying to bolt the DIY bracket in place, so I had to make a special wrench to hold the nut in place while I tightened the bolt from below. To put downward pressure on the nut when I started screwing the bolt in, I just duct-taped a small piece of scrap metal to the top of the wrench. The nut kept slipping out of the wrench as I moved the wrench around, so I used a second piece of duct tape inside the wrench; that piece of duct tape would stick to the top surface of the nut, holding it in place. This assembly let me maneuver the nut above the holes into position so that I could insert the bolt.

Once the DIy bracket was bolted in place, it looked like this:

The lower part of the photo above is the 4Runner exhaust pipe; the tip of the exhaust pipe is on the left, and this photo was taken from the passenger side of the vehicle, just rear of the rear wheel. The white in the upper left corner is the rear bumper.

Next, I bolted two rubber exhaust hangars to the DIY bracket:

When it comes time to attach the diesel heater's combustion exhaust pipe to the underside of the heater unit, I'll support the muffler end of that pipe with these two hangars, which I will bolt to the bottom holes in the rubber exhaust hangars:

 

[4RExplorer]

Fuel Line Connection at Heater Unit

My heater kit included white hard nylon(?) fuel line (2mm I.D., 4mm O.D.). It also included short rubber connectors (2.5mm I.D., 8.5mm O.D.). The rubber connector goes onto the fuel line nipple at the bottom of the heater unit, and the white fuel line goes into the free end of the rubber connector. Clamp at both insertion points with Size 8 fuel injection hose clamps. If using yellow Tygon fuel line (3mm I.D., 6mm O.D.), slip the Tygon fuel line over the white hard nylon fuel line and clamp it lightly with a Size 6 fuel injection hose clamp.

A good order of assembly is:
(1) Place the OEM racetrack oval-shaped gasket on the bottom of the heater.
(2) Place mounting plate #1 on, then a bead of gasket maker, then #2, another bead, #3, another bead, #4, another bead, and finally mounting plate #5.
(3) Tighten the nuts holding the five plates against the bottom of the heater, following the gasket maker instructions.
(4) Install the rubber connector and Tygon fuel line onto the fuel inlet port, as described above.
(5) Attach the combustion air intake pipe and combustion exhaust pipe to the bottom of the heater, using hose clamps.
(6) Install the above assembly into the final locaiton in the 4Runner floor, with gasket maker material between mounting plate #5 and the 4Runner floor.

 

[4RExplorer]

Ammo can fuel tank

The diesel tank supplying the heater will be a 1-gallon HDPE fuel tank which has been fluorinated to level 3 for greater resistance to softening from diesel. To protect this fuel tank from bumps, it goes inside a Fat 50 ammo can. The ammo can will also catch any fuel if the 1-gallon tank leaks or breaks. To cushion the bottom of the fuel tank from the inside bottom of the ammo can, I cut a piece of 1" thick polyurethane foam (which also resists diesel) to use as padding.

The ammo can will go in the driver's side rear corner, on the 3/4" plywood floor. L-brackets bolted to the floor will hold it in place.

I got a vented cap for the fuel tank. So diesel fumes will hang around inside the ammo can. So I got a 1/2" NPT Brass Rollover Safety Vent from #1 Source for Custom Aluminum Tanks and Accessories
– Boyd Welding LLC and installed it, with a 1/2" NPT nut, in the lid of the ammo can, with gaskets on both sides of the hole drilled in the lid. The fuel hose (5/16" I.D., 5/8" O.D.) coming from this safety vent will pass through a 7/8" hole drilled in the 4Runner sheet metal floor (not far from the OEM jack and spare tire change tools) to vent diesel fumes to the outside, and allow outside air to enter the diesel tank as fuel is used up during operation.

Inside the ammo can, a standpipe installed in the top of the fuel tank connects via Tygon fuel line to the fuel filter that came with the heater kit. The fuel line continues through a 7/16" hole drilled in the end of the ammo can (and protected by a grommet), underneath the rear edge of the 3/4" plywood floor, running between the OEM Styrofoam panel and the rear hatch, over to the passenger side of the vehicle, out through a 7/16" hole drilled in the 4Runner floor (near the cold air intake of the heater unit), to the underside of the heater unit.

I will use a separate 2.5 gallon Wavian diesel tank to fill up with diesel at the gas station. Then use that to fill this 1-gallon HDPE tank as needed.

 

[Cwright26]

Ammo can fuel tank

The diesel tank supplying the heater will be a 1-gallon HDPE fuel tank which has been fluorinated to level 3 for greater resistance to softening from diesel. To protect this fuel tank from bumps, it goes inside a Fat 50 ammo can. The ammo can will also catch any fuel if the 1-gallon tank leaks or breaks. To cushion the bottom of the fuel tank from the inside bottom of the ammo can, I cut a piece of 1" thick polyurethane foam (which also resists diesel) to use as padding.

The ammo can will go in the driver's side rear corner, on the 3/4" plywood floor. L-brackets bolted to the floor will hold it in place.

I got a vented cap for the fuel tank. So diesel fumes will hang around inside the ammo can. So I got a 1/2" NPT Brass Rollover Safety Vent from #1 Source for Custom Aluminum Tanks and Accessories
– Boyd Welding LLC and installed it, with a 1/2" NPT nut, in the lid of the ammo can, with gaskets on both sides of the hole drilled in the lid. The fuel hose (5/16" I.D., 5/8" O.D.) coming from this safety vent will pass through a 7/8" hole drilled in the 4Runner sheet metal floor (not far from the OEM jack and spare tire change tools) to vent diesel fumes to the outside, and allow outside air to enter the diesel tank as fuel is used up during operation.

Inside the ammo can, a standpipe installed in the top of the fuel tank connects via Tygon fuel line to the fuel filter that came with the heater kit. The fuel line continues through a 7/16" hole drilled in the end of the ammo can (and protected by a grommet), underneath the rear edge of the 3/4" plywood floor, running between the OEM Styrofoam panel and the rear hatch, over to the passenger side of the vehicle, out through a 7/16" hole drilled in the 4Runner floor (near the cold air intake of the heater unit), to the underside of the heater unit.

I will use a separate 2.5 gallon Wavian diesel tank to fill up with diesel at the gas station. Then use that to fill this 1-gallon HDPE tank as needed.

How did this build hold up? I’m playing with the idea of an onboard 2kw. Any lessons learned?