Servicing my Eberspacher D4

[mbird]

So the first planned maintenance job for this winter now the boat is on the hard was to give the Ebersplutter a de-coke. I do not know when it was done last, and whilst the unit is running fine, I'd rather prevent than cure on something as important as the heating!

I have never done one of these before, so after reading the thread on another forum and also the section on the Le Tonkinois Varnish website http://www.letonkinoisvarnish.co.uk/Eberspacher_Intro_1.html felt sufficiently armed to have a go. I must stress this is only how I did it, and not necessarily the correct way!

I ordered a D4 service kit from Butler Technik for around £18, which basically consists of a new fan gasket, burner gasket, glow pin screen and fuel filter shown in the picture below.

First job is to remove the plastic casing. This is very simple, as the top section simply has two catches at one end then lifts off. The bottom section simply slips off once the rubber seal is removed from the bottom of the unit around the combustion inlet and exhaust tubes.

Next job is to remove the wiring plugs from the ECU, 3 on one side and one on the other side.

There is a single Torx screw requiring a T25 driver bit holding the ECU in position, and once removed the plastic prongs on the other side of the ECU can be squeezed together allowing the whole unit to be lifted off.

Once the ECU is clear, undoing 4 Philips screws allows the fan unit to be removed. Whilst the gasket still looked in good condition, I understand Eberspacher say this should always be replaced to prevent the risk of carbon monoxide leaking into them warm heating air. Not something I'm going to chance!

Removing the rubber grommet allows you to see the glow pin. With the fan assembly removed, the glow pin can be undone with a 12mm spanner and removed. Our one was nice and clean and needed no more than a wipe over with a rag.

With the glow pin removed, the 4 Torx screws holding the burner in place can be undone using a T20 driver bit, and the whole burner removed. The gasket will be in pieces if its anything like mine!

This now gives a clear view of the inside of the heat exchanger. As you can see from the photo below, there was some carbon build-up but I don't think it was too bad. I started off with a toothbrush to remove the worst of the loose carbon (Sue won't be please as it was hers!) and then got a screw driver and some emery paper into the grooves. I was very careful not to damage the fins, and so didn't get rid of all of the carbon, but certainly most of it was very easily removed. I have heard of people boiling the heatexchanger in caustic soda, but when looking at soda crystals in Tesco, they state to avoid contact with aluminium, so I wasn't going down that route! You can see from the second picture below how much carbon came out, so I was quite happy that the job was worthwhile doing.

Here's the cleaned heat exchanger with the new burner gasket in position.

The last job prior to re-assembly was to remove the old glow pin screen to replace it. This is a fine mesh tube that sits in the hole the glow-pin screws into. It's a bit of a swine to get out, and I had to basically pry it away from the surrounding hole, and then hook it out with a bent wire. I'll try to get some much smaller fine-nosed pliers the next time I do this, as there must be a better way. You can see the screen in-situ below in the first shot. A comparison between the old and new shows the old one was looking a bit clogged, and the final shot shows the new screen pushed into position with the supplied insertion tool.

Re-assembly is simply a reverse of the disassembly procedure. I will pop the unit back on the boat in a week or two to test it, and at the same time change the filter in the fuel pump. Fingers crossed that's all the attention it will need for another year. An hour and a half's work and £18 on parts isn't much to keep warm!

[Hockham Admiral]

What a fascinating article, Mark!

I can only imagine what that would cost us to have done!

Now, has anyone a similar story with a Webasto?

[pks1702]

Now, has anyone a similar story with a Webasto? :bow

The UK's leading expert is out there somewhere

[Happy Jax 3]

Well Mark, that didn't look too bad at all, I have seen them when the combustion chamber is half full of coke. Good job well done!

[Hockham Admiral]

The UK's leading expert is out there somewhere

Yes, Perry, but I wouldn't expect free advice from a professional!

[MBA Marine]

Nicely done,

Good to see use of a nice clean, clear light coloured work space, this is very important as you can lay the parts out as you disassemble and not loose small parts. attacking the unit on a cluttered bench in the garden shed is not wise.

If your planning on doing this annually then fair enough you can do it next year but I would have replaced the glow plug regardless, they do not have to look bad to stop working.

When changing the fuel filter I would prime the fuel back through the pipe up to the unit before re-connecting pipe to the unit, it will not fire on air filled diesel bubbles.

[mbird]

Nicely done,

Good to see use of a nice clean, clear light coloured work space, this is very important as you can lay the parts out as you disassemble and not loose small parts. attacking the unit on a cluttered bench in the garden shed is not wise.

If your planning on doing this annually then fair enough you can do it next year but I would have replaced the glow plug regardless, they do not have to look bad to stop working.

When changing the fuel filter I would prime the fuel back through the pipe up to the unit before re-connecting pipe to the unit, it will not fire on air filled diesel bubbles.

Hi Mark

I did um and ah about the glow-pin. I believe they are meant to be replaced every third service according the Eberspacher, and at £90 I thought I'd try to eek out another year from it

With regard the priming of the fuel line. That was something I was going to research. What is the best way to do it?

[BuffaloBill]

Very nice article

I feel our D3LC could do with the same but have been putting it off

£90 for a glow pin ?

[mbird]

£90 for a glow pin ?

Sorry, my mistake. The service kit that INCLUDES the glow pin is £90 (i.e. the gaskets etc in my first photo plus glow-pin)

[ranworthbreeze]

Hi Mark,

Good job on the unit and plenty of pictures for everyone to look at, I know that you have not replaced the glow plug, but did you do anything with the frayed cables on the glow plug? they looked as if they would short out (the loose cores that were not crimped)

Regards

Alan

[MBA Marine]

It will probably be frowned upon but to prime the fuel I disconnect the plug from the fuel pump, using a dummy lead (bit of two core with spade terminals will do,(I have a the connector and wiring that I robbed from an old unit) to connect to the pump. then for ease I use my 12v cordless drill battery as a power source and pulse the pump with voltage, you cannot just wire it up to make it run you have pulse (on,off,on off ect)

If you evacuate the fuel from the pipe between filter and burner first then pulse the pump, it wont take long before you get foamy diesel out the pipe, that will soon be clear diesel with no bubbles (unless you have not connected filter correctly and are sucking air) reconnect fuel pipe to heater, reconnect wiring turn it on and she will be away (assuming you have power in batteries).

[mbird]

Hi Mark,

I know that you have not replaced the glow plug, but did you do anything with the frayed cables on the glow plug? they looked as if they would short out (the loose cores that were not crimped)

Regards

Alan

Hi Alan

I was only one stray strand, so I just nipped it off, the rest were secure.

Mark, thanks for the tip. That sounds nice and simple, and will save the heater trying several start-ups. I had already shut the fuel isolator before disconnecting the fuel line, so it should just be the pump and the short bit of line from there to the heater that need leeding.

[mjt]

The one circled looks a bit suspect. I'd suggest a bit of shrink sleeving would make both of the exposed sections safer.

[mbird]

Hi Mike

Ok, thanks, I'll take another look at it. I assume that's just how they come out of the factory, but I see your point.

[mjt]

They may do. It all depends how carefully they were manufactured. What can happen is that if the insulation is not stripped cleanly it can get stretched slightly. Then, over time and possibly from heat, it shrinks back. I can't see from the photo whether the connections are crimped or welded. If welded it might have shrunk back a bit due to the heat from that.

[mbird]

Just thinking again about this, I'm not goin to be able to put any heat-shrik around the wires since there is a moulded plug on the other end, and I don't really want to go de-soldering the connections. I'm a bit converned about using insulating tape due to the hot environment it lives in. I think I may have to just leave well alone

[mjt]

I must admit that thought occurred to me after I'd posted. I guess you're right, should be ok as long as the wires are routed to keep clear of the metalwork.

You could try putting a little epoxy round them.

[ranworthbreeze]

Hi Mark,

The two part magic putty would do the trick, I always keep some in my boat kit, it is great to put into the holes before you screw the canopy press stud back in.

Regards

Alan

[mjt]

Maybe a better material would be a dab of silicone compound - heat-resistant and flexible.