Espar D5 "S" Heater Glow Plug

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Aqua Puttana

Poly - Thread Finder
I have the older Espar "S" D5 heater in my 2004. I've progressed to getting it to fire and run, but it doesn't start reliably.

My glow plug chamber had what I thought was carbon caked in it. I dug that out. It did indeed seem to be just caked carbon.

The newer style Espar D5 heaters have a "Fuel Strainer" and screen which surronds the glow plug pin. My 2004 heater had no such screened strainer.

More info is here.

https://sprinter-source.com/forums/showthread.php?p=274329

I presume the flame from the glow plug chamber just goes out the screened 3/16" hole "window" into a intermediate burner chamber to ignite the burner. Answer = It does light via the intermediate chamber.

My questions:
Is there a strainer around the glow plug for the older style heaters? (Mine defintely didn't have one.) Edit. Answer = No.

Was the caked carbon I removed supposed to be there? Edit: Answer = No.

Does anyone know how the fuel gets into the glow plug chamber? Edit: Answer = Yes. I do.

Probing with a dental pick makes it feel like there are 2 each small holes down in the chamber. Unless I learn otherwise, my next cleaning attempt will be to use a piece of piano wire with a 90 degree bend at the end to try to open those "holes" up better.

Edit: NEVER poke around in there with a dental pick. Do not damage the screen. It is critical for initial ignition.

The glow pin chamber is the 1/2 round hole to the right.

EsparHeaterSm.jpg

vic
 
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OrioN

2008 2500 170" EXT
Does anyone know how the fuel gets into the glow plug chamber?

Probing with a dental pick makes it feel like there are 2 each small holes down in the chamber. Unless I learn otherwise, my next cleaning attempt will be to use a piece of piano wire with a 90 degree bend at the end to try to open those "holes" up better.

The glow pin chamber is the 1/2 round hole to the right.



vic
Yep... the fuel needs to drip through a small hole on the glowpin chamber wall. You will need to perform surgery to open up the hole. The second hole I believe is a vent hole or a second fuel hole, so it too needs to be free and clear.
 

Aqua Puttana

Poly - Thread Finder
Yep... the fuel needs to drip through a small hole on the glowpin chamber wall. You will need to perform surgery to open up the hole. The second hole I believe is a vent hole or a second fuel hole, so it too needs to be free and clear.
Thanks. :thumbup:

Is there any screen or "fuel strainer"?

Other than the tiny window screen which I dug out while cleaning? :bash: Fortunately I have some appropriate nickel mesh screen for replacement.

vic
 

bc339

New member
Vic, several years ago I had mine apart. While it was apart, the screen was still in place.

Last year, the Espar would not fire up, so I disassembled it again and this time the screen was gone.

I'm having a fun time finding the correct parts to order - the part numbers that I have are not matching up with the latest Espar numbers.

Bruce
 

Aqua Puttana

Poly - Thread Finder
Vic, several years ago I had mine apart. While it was apart, the screen was still in place.

Last year, the Espar would not fire up, so I disassembled it again and this time the screen was gone.

I'm having a fun time finding the correct parts to order - the part numbers that I have are not matching up with the latest Espar numbers.

Bruce
Bruce,
So you didn't find anything in the "D" shaped chamber other than open space?

I believe that my 2004 heater crosses over best to the older 25 style "S" heater.

Some 2004 info is here now.
https://sprinter-source.com/forums/showthread.php?t=30384

I made up a nickel screen to replace the one which I ham handedly dug out. In my defense, it was all carboned up to the point that it appeared to be solid carbon buildup.

This is what I replaced it with.

ScreenInsert.jpg

ScreenInPlace.jpg

Perhaps that is affecting my reliable starts?

I'm considering making a sort of coiled screen unit to simulate the "fuel strainer" units. If that works reliably for me I'll be happy to send you one for testing.

vic
 
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bc339

New member
Vic, yes it was originally in place but either eroded or fell out.
Let me know how yours works out - I'll take you up on the offer.

Thanks!

Bruce
 

Aqua Puttana

Poly - Thread Finder
Vic, several years ago I had mine apart. While it was apart, the screen was still in place.

Last year, the Espar would not fire up, so I disassembled it again and this time the screen was gone.

I'm having a fun time finding the correct parts to order - the part numbers that I have are not matching up with the latest Espar numbers.

Bruce
Bruce,
I'm continuosly learning about my Espar heater. Sometimes it seems like it is one step forward with two steps back.

The screen being gone may be the reason your heater won't fire as you suggest. After I had my heater mostly firing I decided to try and improve the starting relaibility. I went in with a dental pick and an old spark plug gap tool which has right angle gap wires. The 0.020 and 0.025 wires did a great job of digging things out. Too good actually. I uncovered a slot just above the screened window. After opening that up I have no firing now. Just lots of reliable white smoke. I believe I'm now getting too much fuel into the chamber.

The screen across the window continues up through the slot to the fuel pipe. The screen works sorta like a wick in a kerosene lamp. The screen causes the fuel to break up into little segments which will light off easily. I'm pretty confident about that theory.

The glow plug ignited fuel flames out the screened window via an intermediate chamber to the main burner chamber. In the one video they mention being certain that the hole at the end of the newer style fuel strainer chamber is open to let the flame go to the main burner chamber. I haven't found any hole there.

Regardless of how it actually works I know that the screen is an important part of the glow plug ignition. Without breaking the diesel fuel up the glow plug is trying to set a pool or drops of fuel on fire. Diesel can be hard to ignite (but difficult to put out once started) so the screen needs to be intact for starting. By dumb luck my nickel replacement screen must have been close to the OEM specs or I wouldn't have gotten the starts which I did.

I can say one thing for certain. Anyone who is cleaning the old style "D" chamber burner should be very careful during the cleaning process. My recommendation would be to only use carburetor cleaner and maybe a brush for cleaning. I'm thinkin' that a .22 bore brush might be a good choice. I wouldn't attack it with dental picks and pick wire like I did. I ruined my burner assembly by doing that. Edit: I did ruin it, but for a special repair.

I can send you a chunk of nickel screen if you want to try it. PM me with your address. vic

Edit:
I have updated the basic burner operation description and added some parts/reference info in this thread.
https://sprinter-source.com/forums/showthread.php?t=30384
 
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