New member

[tttonyyy]

I've been posting here about swirl flaps and high pressure pumps without introducing myself. How rude of me!

Anyway, my name is Tony - I live with my family in a glorified shed with an aluminium roof (don't ask) and spend as much free time in the summer as possible on boats. This gets in the way of all the things we should be doing to the family shed. I mean, house.

In need of something diesel with a decent amount of grunt for hauling boats up slipways, an M class seemed a good fit to replace our aging Saab 9-5, so here I am.

We also haven't bought a drop of forecourt diesel since we started making our own biodiesel back in 2008 (well, OK, we ran out of homebrew in Europe once and had to top off with diesel to get home, but that doesn't count).

 

[Blobcat]

Hello and welcome,

Love the avatar

 

[Srdl]

Hi Tony and welcome. Sounds an interesting lifestyle.

 

[tttonyyy]

Thank you for the welcome.

Hello and welcome,

Love the avatar

We had a Nissan Largo once with a decal on the back of grumpy cat, captioned "Grumpy cat hates your stick figure family".

I don't like to think of myself as grumpy, as such, more that life has left me rather cynical.

 

[Blobcat]

Thank you for the welcome.



We had a Nissan Largo once with a decal on the back of grumpy cat, captioned "Grumpy cat hates your stick figure family".

I don't like to think of myself as grumpy, as such, more that life has left me rather cynical.

I've seen one "The Empire doesn't care about your stick figure family" followed by a Tie Fighter blasting the stick figures into infinity

 

[A.J.]

Hi Tony, welcome to the forum

 

[om613]

Hello mate, welcome!
Did the EGR shunt work? I made two and didn't test that one...
Was the ML from Oxfordshire Keith's?

 

[McDonald]

Hi Tony, I can't tell whether you're enjoying an alternative lifestyle, or not. Cheap fuel and messing about on boats sounds like fun, but keeping your family in a 'shed' sounds less idyllic. Anyway welcome to the wonderful world of mercedes benz and our happy band of enthusiasts.

 

[tttonyyy]

Hello mate, welcome!
Did the EGR shunt work? I made two and didn't test that one...
Was the ML from Oxfordshire Keith's?

Ohh hello

Haven't fitted it yet, I figured I'd get all the other engine gremlins sorted first before making such improvements, otherwise I won't know what I've broken and what was already like that!

I didn't know Keith had an ML. Not his though, looks like it lived in Hayes, was then owned for a few weeks by the chap I bought it from (felt sorry for him really, he'd got it as a treat for himself but then the swirl flap issue occurred). Nearly walked away from it but finding lower mileage cars without a DPF is getting harder as time goes by.

 

[Craiglxviii]

Hello and welcome!

Word to the wise, MB CDI engines are not recommended for high proportions of biodiesel. Looked into it myself; I’ve seen anything from 10-30% concentration recommended, anything more than that risks gumming up the injectors or knackering the high pressure (rail) fuel pump bearings.

 

[tttonyyy]

Hi Tony, I can't tell whether you're enjoying an alternative lifestyle, or not. Cheap fuel and messing about on boats sounds like fun, but keeping your family in a 'shed' sounds less idyllic. Anyway welcome to the wonderful world of mercedes benz and our happy band of enthusiasts.

Thank you for the welcome.

It is fun but also hard work! Same with the house, though perhaps shed is an unfair way to describe it. I call it a shed because it has 165 sqm of aluminium roofing as designed by a German architect in the 1950s, which lends it certain shed-like qualities. At one point in its history it had 7 back doors, now reduced to 5. Normal it is not (a bit like us), but we love it.

 

[tttonyyy]

Hello and welcome!

Word to the wise, MB CDI engines are not recommended for high proportions of biodiesel. Looked into it myself; I’ve seen anything from 10-30% concentration recommended, anything more than that risks gumming up the injectors or knackering the high pressure (rail) fuel pump bearings.

Thank you and hello!

Do you mean vegetable oil though, rather than biodiesel?

High concentrations of cold vegetable oil in a common rail direct injection engine will gum up piston rings (blow by, loss of compression), end up polymerising in engine oil, and strain injection components due to it's higher viscosity.

On the other hand, properly converted* fatty acid methyl esters (aka biodiesel) with a splash of 2-ethylhexyl-nitrate this engine will love more than diesel itself.

*that's the hard bit, leaving no mono/diglycerides, methanol or soap in the final product - something even some commercial producers struggle with.

Do not worry, "this ain't my first rodeo" with high pressure common rail systems

 

[Craiglxviii]

No, I mean biodiesel not SVO. I run an R Class 320 (same platform as your ML). It’s a big old bus and I did a lot of research on the US biodiesel forums before buying, as it mainly sold there. The consensus was pretty universal, MB diesels beyond around 2002-3 model year stand a good chance of gunking up in specifically the bearings to the fuel system components. VAG diesels are a whole other bag and are designed with biodiesel in mind, but MB aren’t & won’t thank you for it and will line you up a costly repair job some tens of thousands of miles down the line.

 

[John Laidlaw]

Hey and the ‘official’ welcome

 

[carlls]

hi and welcome

 

[tttonyyy]

No, I mean biodiesel not SVO. I run an R Class 320 (same platform as your ML). It’s a big old bus and I did a lot of research on the US biodiesel forums before buying, as it mainly sold there. The consensus was pretty universal, MB diesels beyond around 2002-3 model year stand a good chance of gunking up in specifically the bearings to the fuel system components. VAG diesels are a whole other bag and are designed with biodiesel in mind, but MB aren’t & won’t thank you for it and will line you up a costly repair job some tens of thousands of miles down the line.

My apologies, so many people mix up vegetable oil and biodiesel it's never quite clear they mean what I mean, if that makes sense.

Which are the affected bearings? In winter biodiesel is more viscous than pump diesel unless thinned with petrol which I prefer to avoid.

These chaps in America seem to be doing fine with their Sprinters on biodiesel:

http://www.sprinter-rv.com/biodiesel-sprinter-or-maybe-a-frybrid-sprinter/
http://www.sprinter-rv.com/biodiesel-sprinters-part-two/
http://www.sprinter-rv.com/biodiesel-sprinter-fleets/

Their experience tallies with mine, any problems are likely to be with fuel system pipes and o-rings not rated for contact with 100% biodiesel (and, in some very rare cases, aftermarket fuel filters glued together with incompatible adhesives). Fuel pipe I prefer to replace with nylon, and o rings with Viton.

Any "gunking up" to me says poor fuel quality. There's a lot of it about from homebrewers and commercial producers alike - I wrecked an injection pump back in 2008 when I started out, buying commercially made biodiesel from two large producers. This was down to their poor processes in both conversion and polishing. It was this that prompted me into making my own, as that's the only way I could fully trust the quality - and have successfully run it in other common railers (Volvo V40, Fiat JTDm multijet). I'm very proud of my fuel quality, though it's taken a while to perfect.

And then there is the economics argument. The cost of a single tank of fuel exceeds the cost of a single injector recon/a whole fuel rail assembly from a breaker/a high pressure pump from a breaker.

To pick the most extreme argument, if it lasts three years and the whole car blows up, I'll have saved £8k in fuel and could just go out and buy another one. Obviously replacing fuel system components if necessary is a slightly more economic way to approach it, but you get the point.

I'm rebuilding the high pressure pump this weekend anyway (assuming the seal kit arrives in time) so I'll take a look at bearing surfaces - anything else I should look out for?

 

[om613]

My S210 OM613 did 30K on my FAME before I moved it on (to a MBUK forum member).

No problems with the injectors or the very basic (Bosch CP1) HP pump.

Too many electronics was it...

You'll be fine. I used that same kit you've bought.

Just had my first full MONTH of buying diesel in ten years.

 

[tttonyyy]

Happy to report that the ML is running well on biodiesel with the rebuilt high pressure pump. It was satisfying to hear the nasty diesel clatter get replaced with a softer purr when it made it through the filter to the injection system.

The only problem encountered (thus far) was diabolical fuel economy - 12mpg. We were getting 65 miles to 25l of fuel. I didn't run it on mineral diesel for long enough before switching over to know if it was that bad on mineral diesel. Maybe this is why the previously owner only drove it 2500 miles a year?

As it turns out the thermostat wasn't closing all the way, so it was running cold all the time (mostly 65C and 80C at best - even when it got to 80C it would cool again when off-load coasting downhill). Now it has a 87C opening 'stat the engine runs at 90-92C all the time and the economy is considerably improved.

I suspect mineral diesel with cold running engines isn't quite as much of an economy hit as with biodiesel, since biodiesel viscosity changes dramatically with temperature, significantly affecting atomisation and burn characteristics. Even a healthy dose of 2-EHN wasn't helping, and I've always sworn by that to help with cold-start fuel economy. Maybe it's not as effective as I thought.

 

[Wighty]

Welcome from another om642 non dpf owner

 

[tttonyyy]

Thank you! So far I am enjoying my foray into the world of Mercedes ownership.