where_the_heffalump_roams 917 AF

If the engine has been running you can feel the coolant level in the towel bar . Have the engine OFF before you open the system and be super careful that you are not releasing 80C coolant at pressure!
I think Vermonster got new parabolics.
Copy that. I did wait for the engine coolant temps to drop before carefully cracking open any coolant access points. I don't want to get burned!
I don't think I've ever felt the bathroom heater get warm past the mid way point. I'l try topping it off and I'll cross my fingers that gets the webasto going. But the part of my brain is thinking that isn't the fix. If coolant is passing through the webasto, it shouldn't matter if there is air at the top 1/3 of the system or top 1/2. Someone please correct me if I'm wrong.
 

Joe917

Explorer
And I agree I don't think it is an air lock issue. You can try to find someone to run the diagnostics or swap it out for a new unit for about $1500. The Webasto is rated to 3000m, that is still higher than the Espar with the altitude metering pump.
One other thing the Webasto does not do well sitting unused it needs to cycle once a month, which reminds me I need to cycle the one on my van!
 
And I agree I don't think it is an air lock issue. You can try to find someone to run the diagnostics or swap it out for a new unit for about $1500. The Webasto is rated to 3000m, that is still higher than the Espar with the altitude metering pump.
One other thing the Webasto does not do well sitting unused it needs to cycle once a month, which reminds me I need to cycle the one on my van!
The unit that is in there right now is a rebuilt one I just installed.

The issue occurred while in use some months ago. I was posted up in the mountains for snowboarding. Woke up to 10C indoor temps while it was -10c outside. I tried resetting the Webasto, it would cycle on for 5 minutes and power down. I had wait until the day warmed up just enough to get the truck to start, I was almost stranded on the mountain. It gets a lot of winter use and this occurred at the end of winter. So the failure occurred during continuous use.


I"m starting to wonder if it's the thermostat or something external to the Webasto?
 

NatersXJ6

Explorer
The same heater acts as a block heater, yes? Do you have a simple diagram of where all the components are plumbed to and where the temperature sensors are?

Do you have an infrared thermometer (temp gun)?
 
The same heater acts as a block heater, yes? Do you have a simple diagram of where all the components are plumbed to and where the temperature sensors are?

Do you have an infrared thermometer (temp gun)?

It does act as a block heater by heating/circulating coolant.
I don’t have any diagrams.
My understanding is the thermostat is the only sensor. It sends a signal to the heater to activate whenever the temps drop below the setting.
I don’t have an infrared gun.


Sent from my iPhone using Tapatalk
 

joeblack5

Active member
In the wiring harness from x1 pretty close to the heater should be a small box with a 2 or 5 amp fuse. That harness goes to the inside with a switch timer or thermostat.
I like simple so we have switch.

The startup procedure,
The fan runs for a while to clear combustion gasses, then the glowplug starts, then fan starts again on slow speed with a ticking noise from the fuel pump..around the same time the coolant circulation should make some noise. Check if your valves to the truck are open and no blockage of coolant flow.
If you have an air leak in the fuel line and the fuel has drained ack in the tank then it takes to long to start the webasto so it times after two or three times of failure start it sets a fault code and you need the disconnect power to the unit.

If you messed with the fuel line then be sure that the plastic feed line in pushed properly in the rubber connector at the suction side of the pump. Air bubbles are easily trapped and that impedes the working of this style pump.

You can download the diagram and manual.
Good luck.

Johan
 
In the wiring harness from x1 pretty close to the heater should be a small box with a 2 or 5 amp fuse. That harness goes to the inside with a switch timer or thermostat.
I like simple so we have switch.

The startup procedure,
The fan runs for a while to clear combustion gasses, then the glowplug starts, then fan starts again on slow speed with a ticking noise from the fuel pump..around the same time the coolant circulation should make some noise. Check if your valves to the truck are open and no blockage of coolant flow.
If you have an air leak in the fuel line and the fuel has drained ack in the tank then it takes to long to start the webasto so it times after two or three times of failure start it sets a fault code and you need the disconnect power to the unit.

If you messed with the fuel line then be sure that the plastic feed line in pushed properly in the rubber connector at the suction side of the pump. Air bubbles are easily trapped and that impedes the working of this style pump.

You can download the diagram and manual.
Good luck.

Johan
Thanks for the through start up explanation!

I don't believe there is a blockage in the coolant line. At least none that I have found.
The fuel pump has been removed 3x, the filter changed, and the last time the fuel pump was swapped out. It has been reset and about a dozen times since. I'm taking a few days off from heffalump projects. My old man back is acting up and I wanted to get back in the woods to ride my bike once my back eases up.

I did contact Webasto and asked for a list of dealers that could assist with repairs. They responded by asking me to call their tech support team. I'll do that next week.
 

NatersXJ6

Explorer
A temp gun is small, lightweight and only about $20-40. It is a very useful tool for diagnosing all sorts of things, including checking tires, bearings, brakes, oil coolers, heaters, air conditioners, radiators, etc. I highly recommend one for anyone driving a heavy truck or towing frequently.

With that being said, I wonder if your engine thermostat is opening and letting coolant circulate properly?
 

Joe917

Explorer
The same heater acts as a block heater, yes? Do you have a simple diagram of where all the components are plumbed to and where the temperature sensors are?

Do you have an infrared thermometer (temp g

A temp gun is small, lightweight and only about $20-40. It is a very useful tool for diagnosing all sorts of things, including checking tires, bearings, brakes, oil coolers, heaters, air conditioners, radiators, etc. I highly recommend one for anyone driving a heavy truck or towing frequently.

With that being said, I wonder if your engine thermostat is opening and letting coolant circulate properly?
It has nothing to do with the engine loop. The engine thermostat position would also be irrelevant it only controls water going through the radiator.
 

NatersXJ6

Explorer
Yeah, so having separate loops would be one of the reasons to ask if there is a diagram. In any event, a no fire condition means an air problem, an exhaust restriction problem, a fuel problem, or a fire / signal problem. It sounds like fuel has been verified. Exhaust and intakes should be verified clear, especially with all the time spent sitting in shops, rodents or nests could be present. Then verify that fire signal is received, and that ignition / glow circuit works. I would think most likely is a water flow problem creating the “wrong” temp at the sensor and inhibiting the start signal, based on the discussion so far. Next most likely would be a bad glow circuit/ bad thermal or fire eye, whatever is used, to verify safe operation, thus the shutdown.
 

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