w210 webasto information needed - Page 2 - PeachParts Mercedes-Benz Forum

dude99 · #16 11-15-2015, 07:26 PM

Yes, the exhaust got warm, and progressively more forcible for a few minutes, then slowed down, turned off, and then did the same thing again. I'm going to comb through WIS and see what else I can learn and if it mentions the flame sensor anywhere...

atypicalguy · #17 11-16-2015, 12:13 PM

It must have a thermostat for the coolant temp right? Otherwise it could boil the coolant off and start the car on fire.

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dude99 · #18 11-16-2015, 01:53 PM

Yes, I believe it's designed to run until the coolant temp reaches 60*C

97 SL320 · #19 11-16-2015, 07:00 PM

Given your description in post 16, I'd say some external force is shutting it off. A 100% failed flame sensor will allow the burner to run for a few seconds then shutdown.

The sensor could be failing when hot but for home heating burners that generally does not occur.

Does your aux coolant pump turn on? Do the hoses at the aux heater heater get warm?

Past that I'd have to see the factory manual.

dude99 · #20 11-16-2015, 08:17 PM

I'm going to dif through WIS and see if I can find info on the flame sensor. Thats a good call. There is something else wrong though. It was below 5*C today and it didn't even try to fire up when I started the car... The temp sensor works as the inside temperature display is bang on....

tombance · #21 11-17-2015, 01:07 AM

I had a W202 C220 CDI, 1999 model in the UK. It had a Webasto that like you said was supposed to come on at startup if the outside temp was less than 5C or so. It would then switch off when coolant got up to a certain temp (40C if I remember correctly).

The aim of it was to provide cabin heat quickly on cold mornings, as the CDI's are so efficient that they take AGES to heat up when idling or in traffic. They obviously replaced it in newer models with a PTC heater in the heater box.

Mine was completely automatic in operation, but there was a switch in the center console with an LED on it that could be used to disable the Webasto.

They're quite unreliable, mainly due to their susceptibility to corrosion due to their location on the car, and they have a glowplug which can go.

dude99 · #22 11-17-2015, 03:26 PM

Yeah, that's what my problem is. I don't get any heat and the engine take ages to warm up. I changed the thermostat and that didn't help and while I was under there I saw the webasto...

Currently going through a bunch of polish websites translated through google... not great, but they seem to have more info.... no if only I spoke another language so I could ask questions....

I have since leaned that my model doesn't have nay switches to control it. It's fully automatic.

97 SL320 · #23 11-17-2015, 08:12 PM

Another few thoughts. There has to be some sort of fuel pump and filter, if one of them are clogged that could cause it to go out. When running, does the heater make a steady flame sound or an uneven or popping?

Also the nozzle could be clogging limiting flame size. All of these could cause the system to think the flame has not established.

dude99 · #24 11-17-2015, 09:03 PM

The more I read the more I realize that I'm probably going to have to pull the entire unit out and take it apart and clean it... bummer...

dude99 · #25 11-18-2015, 12:53 PM

Hmm, well it was 2*C today when I went out and started up the car. As I got out and started scraping the windows I heard the blower on the webasto start up, then heard a muffled sound that I assume was it igniting, then a puff of smoke and it shut down...

So from this I gather that the control system is more or less functioning. When I got it to fire last time I could also hear the dosing pump (fuel pump) pulsing. I am going to assume as other have suggested, that at this point the most likely culprit is a dirty flame sensor. If its nice this weekend and I have some time I think I'm going to pull it out, disassemble it, and give it a good clean.

dude99 · #26 11-19-2015, 11:46 AM

Today's startling development:

Temp outside was hovering around the 0*C mark this morning. Started up the car, heard the webasto blower turn on like yesterday, then heard the blower stop and the muffled sound of what I have been assuming was the flame igniting, or at least trying to, but this time, the blower came on, and the exhaust got hot with moisture in it (a sure sign of combustion) and it stayed running!!!!!

I had gleaned from the polish\Finnish forums that when these are not used for a period of time the fuel line can loose its prime and take several cycles to re prime itself.. We'll see if it works tomorrow morning or not.

What a difference though, I can't believe how much faster the car heats up with it!

dude99 · #27 11-20-2015, 10:38 AM

Day two of the webasto firing up in the morning. It warms up so much faster now, I can see why they equipped these cars with them.

GregMN · #28 11-20-2015, 11:00 AM

Can that heater be used to pre-heat the engine before attempting to start in really cold weather ?

dieselbenz1 · #29 11-20-2015, 11:11 AM

Although I have never owned one I did a lot of reading years ago and yes they are intended to warm the engine in really cold weather. I seem to recall in -30 temperatures it takes about 20 minutes to get the engine coolant up to 60 degrees C. At the time they were in the $1800 range which was a bit too rich for me.

If you could add a remote to start it that would be ideal.

daw_two · #30 11-20-2015, 11:17 AM

I have the owner's manual to the unit I have for sale. Our units may be similar. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/358373-fs-webasto-heater-memphis-tn.html

Maybe I can dig it up sometime this weekend and post some pics for you. As I recall, the control unit I have, has a timer on it; maybe even a temperature setting. Could it be set to come on at a certain cold temperature?