use a marine water heater to preheat for winter?

[columnshift]

Having read a discussion on another board, what is the feasibility/ safety/ wisdom of trying to plumb in a fuel-run water heater into the cooling loop of a diesel vehicle with the idea of having something that will pre-warm the vehicle out of range of an electric plug in so that it will start well even in very cold weather?

An example would be here: http://www.webasto.com/us/markets-produc.../water-heaters/

There are electric sources for everything, but limits on how much power you can run through one plug. (fuel could get hotter faster) I've seen systems where the coolant is plumbed to preheat fuel lines, fuel tank and everything else that can gel up in -40 temps - that works great when the engine is already running, prewarming and precirculating the coolant gets all that started.

Plus all the endless discussions of how an engine has greatly reduced wear when starting at real running temperatures (above even summer 'cold' temperatures) makes me wonder if running such a heater year round would make sense if you could flip it on in advance of normal vehicle use to get to and maintain normal engine temp. (assuming you didn't mind the fuel usage) Since 120vac free plugins just aren't available in most places that means fuel powered heat is the way to go.


Now talk me into or out of it.

 

[Rand]

They sell those.. no need to cobble something together.

http://www.arctic-fox.com/fuel-fluid-warming-products/diesel-fired-coolant-pre-heaters

 

[abycat]

webasto and espars are in 99% of the on or off road diesels up here. Pretty much a must have.

 

[JimPghPA]

I have an Espar (use to be the competitor to Webasto) air heating system that runs on gasoline, installed in my 1985 Olds 88. One thing I have found out is that it uses one brushed motor to move both the combustion air and the heating air. That brushed motor is the weak point in the design. It has a life expectancy of only about 200 hours, not really a lot of use before it goes bad.

Also, there is a glow screen and a glow plug. The glow screen is a cindered high-temperature metal. There is a fuel pump that is a simple solenoid pump that the system pulses at a varying rate to regulate the fuel flow. The fuel pump pumps fuel into the high-temperature glow screen, and the glow plug runs for 20 seconds at startup until the glow screen becomes hot enough to maintain combustion. You can not see the inside of the glow screen when the unit is running but the glow screen gets hot like the mantle of a coleman gas lantern. You have to replace the glow screen about once a year, and it can get carboned up and be hard to remove. A can of carburator cleaner works well to clean up the cavity for the glow screen once you remove the old one. You can not reuse the glow screen because it gets all carboned up and you end up busting it up during removal. The glow plug last for several years but to keep it reliable you will want to replace the glow plug about once every three or four years. You are probably looking at something like $30 for a glow screen, and another $30 for the glow plug, though those prices are several years old and the price probably has gone up.

A hydronic system like you are talking about will have two brushed motors. One to move the combustion air, and one to move the engine coolant. Both of those motors have brushes and a very limited life expectancy. I have heard some say that you can expect thousands of hours from those motors, but my experience with my Espar air heating system is that the reality is more like a couple of hundred hours life expectancy. So you will want to use that system sparingly. Think pre-warm on the coldest days, but not continuous use like sleeping in the vehicle with the Webasto system supplying the heat.

I understand that there are some electric heaters that can be installed in the freeze plug location. That would have a longer life expectancy than any system with a brushed motor.

If you decide on the fuel fired hydronic Webasto heating system be aware that there are both diesel and gasoline versions of these systems.

 

[Garak]

There are also various ones available, with the same basic principle as this picture, just used for illustration. Canadian Tire, for instance, sells various types of them up here, for different hose diameters, and different wattage, and different internal capacities.

 

[Trav]

I bought a nice low hours Webasto unit for my VW for $129 Euro and will be putting that in this fall. They work great, this will be the third one I have used.
This one is newer with the remote control so no need to program it.