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Unimog Moderator
250GD Wolf
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Discussion Starter #1 (Edited)
I'm wondering if anyone can help.

My Esbar in cab heater was working just perfect until it cut out yesterday.

Now it will come on, and does two things:

It either runs for 3 minutes, then shuts off blowing cold the entire time, but it does smoke out the exhaust (manual states to try it again, if continues take to esbar dealer for service)

Or it runs for the 3 minutes, blowing cold, then kicks into high (normal operation) when it starts blowing warm air, runs for 6-20mintues, and kicks off.

I've pulled the glowplug (first glowplug I've ever seen :eek:) and it was hot to the touch, but other than that I'm lost. I've checked it for continuity with my OHM meter and it reads fine (0.07ohms)

There is a safety thermal cut off switch on top, but it hasn't been tripped, there's also a reset on the dash, it also hasn't be tripped.

I can also here the fuel metering pump pumping, and it smokes out the exhaust when it does run over the 3 minutes, so I'm sure its getting fuel.

Any help is as always, much appreciated.

EDIT: I can hear what I think is it trying to light, it sounds like a tiger torch or small propane torch, but it doesn't sound like it gets fully lite, you can hear it "whoooph...whooph............whooph.whooph.whooph..........whoooph" but it doesn't seem to stay lite, and the exaust is more like when you shut it down than start it up, ie, lots of thick smoke, like the end of the combustion cycle. Not the cleaner less pungent smoke when its first turned on. I'm leaning towards glowplug, I have a call into my Esbar dealer on the hunt for one. Any way to test a glowplug?

-Trev
 

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1957 Unimog 30, 1999 E320, 2004 E320
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I've never touched the air heater but I do have an Espar coolant heater and I'm pretty sure the combustion side of the heaters are similar, just a different heat exchanger.

To test the plug I'd start with an ohm meter and make sure it's not burnt out, but given that the machine runs I'd suspect it's fine. You could apply power to the post and body, the coil will turn red quickly if it's functioning. A word of caution, unless the voltage is marked on the plug don't assume it to be 12 or 24V, just apply enough power to get the coil warmed up.

If that's ok the next thing I'd do is install the plug back into the heater and clip a volt meter to the power pin. Start the heater and monitor the voltage to ensure it isn't falling off as the heater runs.

With my coolant heater, when the fuel pump is running the suction line would always have a strong kick to it with each pulse, I'd check that too, if your pump isn't pushing enough fuel that would also impact how the heater runs. If you can pull the pump and injector it might be worth while as well, at least you can see if the fuel is being atomized or not.

If all else fails you can try calling Espar support at 905-670-0960, I've called them in the past when my heater was acting up and they gave me a couple hints that were not included in the manual to get my problem sorted out. You'll likely have to keep trying as they seem to be busy people and returning voicemails wasn't their strength.

Jason
 

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Unimog Moderator
250GD Wolf
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Discussion Starter #3 (Edited)
Thanks Jason,

I clipped my voltage meter to the two posts on the glow plug, its rock steady at 9.5volts until it kicks out. No drop. The batteries in the Mog are strong and fully charged, so I'd assume its getting the right voltage even though the heater is 24volt. There must be a resistor or something that cuts the voltage down, I'm looking at the wiring diagram but its confusing.

Edit: Manual says indeed there is a resistor, they call it a "glow plug series resistor, 24volt model only"


The Fuel Metering pump kicks hard, I can feel it moving the supply hose each pump, I've also checked the combustion intake hose and its clear and sucking air.

I found a new glowplug at a dealer in town, but its a few days out, hopefully I can get it before they close for Xmas and give that a try.
 

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Unimog Moderator
250GD Wolf
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Discussion Starter #5
Update for any whom are interested,

I spoke with Esbar and they were very helpful, he nailed it down to a fuel delivery issue, or as Jason said, an injector issue (we will get to that later)

I took the unit completely apart, it separates in to two halves inside, a motor half and a combustion chamber/flame-box half.

Esbar said there's a mesh screen that surrounds the glow plug, and that diesel fuel is simply "injected" or rather, just squirted from the fuel pipe onto this screen, he indicated if said screen was gummed up it might have issues holding a flame. He also told me how to meter the fuel, using an eye dropper. I never got to that step.

Once I seperated the motor half and flamebox half, I noticed how carboned up the chamber was, I soaked it in brake cleaner for a few hours, then washed it as best I could with a toothbrush and warm soapy water. I was sure to make sure all the brake cleaner residue was removed for obvious explosive hazard reasons.

I had chunks of carbon the size of marbles coming out.

I then cleaned the screen as best I could, put it all back together and voila, its running, and producing better heat than ever (probably due to clean chamber walls conducting heat better)

Esbar recommended once in a while (Once a year, before winter, depending on use) to run it for a "few hours" on Kerosene, he said it burned hotter, and would clean up and burn out all the gunk inside. I'm going to locate me some Kerosene and do it as a service, in case I didn't get it completely clean inside.

Hope that helps if anyone has similar issues in the future, I'll update if its not a permanent fix, and it comes back to haunt me.

-bit warmer Trev
 

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I then cleaned the screen as best I could, put it all back together and voila, its running, and producing better heat than ever (probably due to clean chamber walls conducting heat better)
Good to know it's warm again.

BTW, Isn't it called Espar, not Esbar ?
 

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1973 416 Doka, 1978 416 Doka, 1980 416 Doka..... Help me, I can't stop buying them!!!
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Trev,
Thanks, I have a 12v that I couldn't get going and it sounds like you have found the cure for it! I will have to dig it out and take it apart. I bet I find it all gummed up inside as well.
 

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Vehicle: 1397 Portative Organ Normally Aspirated....U411, U2450,463 300GD
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I thought you were talking about Pablo Escobar....In which case you could clean it out with some Bolivian Marching Powder.........
 

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250GD Wolf
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Discussion Starter #10
I thought you were talking about Pablo Escobar....In which case you could clean it out with some Bolivian Marching Powder.........
Booger Suger? Not for this guy ;) I smelled enough diesel fumes to keep me going for the holidays however :eclipsee_steering:
 

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Vehicle: 1397 Portative Organ Normally Aspirated....U411, U2450,463 300GD
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Ditto on the diesel...brought the Christmas tree home behind the diesel Landcruiser...now we have a diesel Christmas tree. The wife and kids weren't as excited as I was....
 

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ex-moglet u1700 (ex U1300L)
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Hi

I've had a series of problems with my Eberspacher, which I think I've got to the end of after about 6 months!

One good thing to do is change the panel you turn it on with for one that can give you the error codes, then although it may still lock out after repeated failed starts you can unlock it yourself without taking it to a dealer.

Both my water pump and fuel pump had ended up over time being more horizontal than outlet up so didn't de-air by themselves. This ended up eating the water pump.

The air blower motor also played up a bit and got replaced, along with the heater plug, heat sensor, seals and gauze. The dealers can be big £$£, but Ebay, particularly a man in Turkey, is much cheaper.


Anyhow, a while back mine did the same as yours seemed to. I checked all the things the dealer said to try, as well as what the error codes suggested. Check fuel supply was a recurring one, but it had fuel, smoked a lot but wouldn't burn etc.

The fuel test is to measure the fuel pump output on start up during its first attempt, which was spot on. Each time I took it apart it burnt properly for a while, but next time no go, or just a few minutes.

The fuel line between pump and burner was sleeved for protection. Taking this off the pumped fuel in the line looked like lemonade if you shook it before opening, lots of bubbles! Each time I'd dismantled it the fuel line was clamped up out of the way letting the air out, allowing the first burn to be fine for a long time. The fuel test was of course OK as the air leak was after the pump, you don't measure the air coming out too!!

I hope you have fixed your problem, but renewing the rubber joining sleeves each side of the fuel pump etc may be a good plan occasionally anyway, mine were quite hard, and make sure all the joints are fully butted. New rubbers for pence have removed the final, hard to find problem that was right infront of my face, although the odd air bubble persists which is "normal". Small diameter pipes with such a small fuel quantity means they are quite sensitive in this respect I'm told.

Cheers

Jason

:)
 

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Gentlemen,

I think we've stumbled across one of those eureka get rich quick ideas... :D:D

Merry Christmas!

-Trev
YO HO HO BOYS AND GIRLS!.....

I think you've hit the nail on the head Trevor...So amongst the various diesel scents there will be a specific Unimog diesel scent...there is no smell like a Unimog diesel...'specially the older ones. This will conclude my Espar highjack.

Merry Christmas to All
 
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