vito 110cdi engine pre-heater

[johnnythefox]

I have a Vito 110cdi (2001) which has been a great van apart from rust!
The van is fitted with a pre heater which I think burns diesel which heats up the engine when really cold. It has stopped working and now the engine will only get to about 60 deg unless on the motorway and takes an age to warm up at all.
Anyone else had this problem?

 

[mersum1es]

Change thermostat!

 

[johnnythefox]

i changed the thermostat which made no difference. From new the van has always only warmed up at low speeds with the preheater.

 

[Danny DeVito]

Good info here it covers most of the heater. Diesel Booster Heater - Benzworld.org - Mercedes-Benz Discussion Forum

 

[mersum1es]

Still not warming over 60???? Should do that anyway now, auxiliary heater is only for quicker heating not for getting higher running temp... I've never heard if Vitos has also 'low temp radiator' isntalled in fuel line (you'll foung it some W210, W202 and W203 diesel models) and there is also separate thermostat which will prevent engine warming up enough. Low temp rad looks something like this, if installed (part 22) http://www.mese.fi/forum/userpix/6563_kylman_ilman_jaahdytin_1.jpg

Try unplug fuses of the heater first, that will reset fault codes which may prevent heater starting.

 

[Tinkerer]

I have one of these and as I understand it, it operates when the outside temp is below 6C and the engine temp is below ~40C to give some comfort to the occupants i.e. it should not affect the 'normal' running temp of the engine. If you have already changed the thermostat I guess the question is did you buy a good one? I have never heard of a low temp radiator ....... but that does not mean that it does not exist.

 

[Danny DeVito]

I have one of these and as I understand it, it operates when the outside temp is below 6C and the engine temp is below ~40C to give some comfort to the occupants i.e. it should not affect the 'normal' running temp of the engine. If you have already changed the thermostat I guess the question is did you buy a good one? I have never heard of a low temp radiator ....... but that does not mean that it does not exist.

I dont think outside temp matters. The booster should run until normal operating temp is achieved at about 80 i think it was . The engine must be running and the heating on and fan on. It cuts out when the fuel in the tank gets low.

I'd question the stat though too. If u run the engine and clamp the top hose for a while the temp should go quite high soon enough and this might tell if the thermostat works or not

 

[johnnythefox]

when I bought the van I was told that the cdi engine is so efficient that the heater is fitted to warm the engine up. I used to leave it on all the time in the winter as it warmed the engine up quickly and then shut off at about 80 c. You are right Danny you must have at least 1/4 tank of fuel as it burns diesel to create heat. It sounds like a turbine when its working. The thermostat was an aftermarket part so I think I will buy one from mercedes and see if that sorts it. Thanks for all the info chaps