Choked inlet manifold on ML270

[Alex Crow]

for some time now i have been scheming a new use of the 'egr shunt'. for those interested, have a read of the 'P2036-001....' thread and all will become clear!

 

[LNM]

I bet not many chavs bother to read _this_ little lot and act upon the instructions.

 

[LNM]

and more to the point, this kind of activity must be of interest to MB engineering development.

And here's me, with a sweaty petrol M103 engine. Still suffers from a right load of crud in the intake air paths from crankcase gas recirculation though !!

 

[supermed41]

shunt

Just to let everybody know, I have had no problems since my EGR shunt and I have done over 1000 miles.

I have also noticed that my turbo whistle is more evident at low rpms-speed but again am very happy with the results!

I have also noticed that my engine takes less time to warm up and doesnt stay as warm, but I think that my thermostat is gone too as it did this before hand.

If anybody needs any help on wiring or info let me know as I did the job myself.

Thanks all[/QUOTE

I live in Reading and i need your help with my ML PLEASE!!!!!!

 

[Hybrid]

Great Tech guys. I've been reading through with ineterest. I live about 15km from Oigles and have a ML270 playing up at right about the exact same mileage as his. Car puts out a plume of black smoke under hard turbo acceleration then usually within 20 mins will go into limp mode (big loss of power). I'm guessing I either have this EGR inlet blockages or blocked cats. The guys that have done this how have you cleaned the actual engine cylinder head? I can understand the inlet pipework, egr and manifold but getting into the engine would require taking the head off correct? Is there anything that can be run in the fuel to clean it?

Also specifically to Oigles do we legally have to run cats on diesels of this age here in Queensland?

 

[oigle]

Great Tech guys. I've been reading through with ineterest. I live about 15km from Oigles and have a ML270 playing up at right about the exact same mileage as his. Car puts out a plume of black smoke under hard turbo acceleration then usually within 20 mins will go into limp mode (big loss of power). I'm guessing I either have this EGR inlet blockages or blocked cats. The guys that have done this how have you cleaned the actual engine cylinder head? I can understand the inlet pipework, egr and manifold but getting into the engine would require taking the head off correct? Is there anything that can be run in the fuel to clean it?

Also specifically to Oigles do we legally have to run cats on diesels of this age here in Queensland?

The amount of gunk inside the cylinder head ports is of no real consequence. Just clean what you can from the outside when the manifold is off. The big problem is around the swirl flaps and restriction within the manifold itself. Of course the EGR can jam which causes problems too. No fuel cleaner will affect this area as the injection is directly into the combustion chamber. Cleaning the inside of the manifold is a nightmare too. Awful stuff.
Shunt fixes the problem completely. Mine doesn't smoke at all now, even with the chipped ecu. Expecting gain in fuel economy.
Re CAT in Qld. Law states that if a vehicle is fitted with a cat, it should not be removed. Best way to not get caught out is to remove the cat, put a broomstick through the thing, shake it out and reweld it back in place. The internals are quite brittle and break out easily.
I think you should look at shunt first and look at CAT if and when you have to.
Redcliffe Car Electrics did my shunt for me - talk to Brock if you want him to do yours. Phone 32848459.
Of course, the manifold and egr need to be cleaned out and fixed first. I can reccommend a good mech who did mine if you need help at a reasonable price. PM me if you need any more help.

 

[Hybrid]

Thanks Mate! I'm pretty handy with a spanner and multimeter so I'll have a crack myself first. I don't suppose there's a link around to the workshop manual section on removing the intake manifold? I'm sure I can work it out but some diagrams generally save me a few skinned knuckles.

 

[alexanderfoti]

Sorry for the late reply.

I am happy to help any body with wiring etc, but Im not sure if me actually doign the wiring is a good idea. while I am confortable with working on my own car, im not sure it would be good If I broke somebodys elses

plus im no mechanic

Any help do let us know!

 

[Naraic]

Photos would be good, if you have any.

 

[alexanderfoti]

I dont have any but can take some, its only a couple of wires, the diode/resistor are covered in electrical tape.

I intend on tidying it up at some point.

will get some taken tonight.

 

[toby1]

Awesome thread everyone. Can't say I understood it all, but I have a better understanding of EGR if nothing else.

I'm definitely up for trying this EGR shunt to see if it will solve my smoke issues. I have absolutely no electrical skills whatsoever, so if a sticky is made at least I could put it under the nose of a techy and see what he makes of it.

AlexanderF, would you be able to help as your car is almost the same as mine?

Cheers all.

 

[supermed41]

I dont have any but can take some, its only a couple of wires, the diode/resistor are covered in electrical tape.

I intend on tidying it up at some point.

will get some taken tonight.

Thanks Alex, that's kind of you, i'm looking forward to seeing them.

 

[alexanderfoti]

Will defo get some taken today

 

[soup nazi]

OK Boys
I have bought the relevant gear to do the job, although I am using 1W resistors as my electronics store does not have the 0.25's, I am told it makes no difference, they are just a fraction larger.

The wires on my 2003ML are Brown/White from pin 5 on my MAF to pin 24 in plug 2 on my ECU.

Grey/Black from my EGR vacuum transducer back to pin 50 on plug 3 at the ECU.

Red/Grey for the 12V power from ECU plug 3 pin 37.

I will cut it in in the next few days, so lets see how it goes hey.

 

[oigle]

Anyone looking for further detailed info on this matter should now look at the new thread made by dieselman on the subject.
I have asked that it be made a sticky. Thread is
http://forums.mercedesclub.org.uk/showthread.php?t=68928

 

[Hybrid]

Alright, going to have a crack at cleaning the gunk out of the Mrs' ML270. What gaskets am I going to need? Just the EGR and intake manifold? Also any tips from those guys that have done it for stripping the tar? I was thinking of soaking everything overnight in biodiesel. Would that wreck the swirl flaps or any other plastic parts? I'll post any shunt related stuff I do in the other thread.

 

[oigle]

I didn't use any new gaskets/seals. The manifold and egr seals are O ring type. Just be careful with them. Grease the EGR seal before reassembly so it will slide in OK.
I used a strong hot alkali bath and a high pressure sprayer to help get the gunk out. I'm sure there must be better ways as it took ages to get it out.

 

[soup nazi]

From what I understand these manifolds are prone to leaking from where the guide vane control shafts enter. Anyone know what type of seals are used in these shafts and if they can be renewed?

Anyone got a step by step for the removal of the manifold? Things not to do etc.
SN

Edit. I would renew all the "O" rings as they tend to go hard and crack, leak with time. I have cleaned three diesel manifolds and found petrol to be a reasonable solvent to use. Still slow going. I have heard the Alkaline bath Oigle used is good but I haven't tried it, I believe most mechanics use it as well.

Oigle
Did you mix you Alkali bath yourself?

Hybrid
If you do it I would appreciate some photos or info on any problems you face. I will do mine but am still a couple of months away yet.
SN

 

[rovingHawk]

Speaking for a mondeo EGR, I clean it with a big disposable rag for the worst of the gunk, a finer rag to do a bit more, then I use WD40 and a clean cloth to dissolve the rest- it works fine. Ethyl alcohol also works well.

RH

 

[oigle]

From what I understand these manifolds are prone to leaking from where the guide vane control shafts enter. Anyone know what type of seals are used in these shafts and if they can be renewed?

Anyone got a step by step for the removal of the manifold? Things not to do etc.
SN

Edit. I would renew all the "O" rings as they tend to go hard and crack, leak with time. I have cleaned three diesel manifolds and found petrol to be a reasonable solvent to use. Still slow going. I have heard the Alkaline bath Oigle used is good but I haven't tried it, I believe most mechanics use it as well.

Oigle
Did you mix you Alkali bath yourself?

Hybrid
If you do it I would appreciate some photos or info on any problems you face. I will do mine but am still a couple of months away yet.
SN

No, I took it to an engine recon place where they use such a bath to clean engine blocks and heads before working on them. Pretty strong stuff - I've put burnt and blackened home oven parts (trays etc) in that bath overnight and they come out clean as a whistle. Being a bit concerned about the effect of the alkali on the rubber o rings in the swirl flap pivots, I chose to use a pressure spray instead of a long soak. Had to do it a few times and was hard going.
Am hoping that, now the muck isn't accumulating in the manifold, that the PCV oil mist might serve as a good lubricant for the swirl flap seals and keep them in better order. Be good if it increases their longevity. Not sure if one can source those seals separately.