W639 - Black death again on back injector, advice needed.

[BloodSexMagik]

Hi,

Vito 111 55 plate.

Noticed some whiffs of fumes recently, took air filter off today and injector number 3(or poss 4) is leaking. I already fixed injector 1 last year

Because the injectors are arranged front to back, injector 1 was easy to access but 3/4 look a lot harder! Has anyone managed to replace the seals in these without removing the engine? Or am I better to take it out and replace all three while i'm there?

Cheers.

 

[BlackC55]

Just remove the bulkhead and it's then easy.

 

[StMarks]

My injector 3 was chuffing when I got my W639 109cdi
I normally do everything mechanical to my vehicles.; Not only do I enjoy the satisfaction, but I can be confident that the job has been done conscientiously.
However....
When I read up about the removal of these injectors I came across numerous instances where people had caused serious (& expensive) damage attempting what should be such a simple task.
Furthermore my Vito is a 2007, so the engine has the later design of injectors & my injector removal kit doesn't fit.
So I reluctantly decided to hand it over to my Mercedes Dealer to do. I cleaned out the accumulated "Black Death" myself first, then drove it to them with the engine cover removed & all ready for them to remove the injector.
Luckily their work has a 2 year warranty, because it started to leak again this Autumn & they had to do it again.
I only wish I had their equipment to do it myself.

They certainly did all the work without removing the engine, although I think they removed the scuttle bulkhead.?

Hth.

 

[BloodSexMagik]

Cheers for the replies. I'll get out tomorrow and have a look at how to remove the bulkhead.

I replaced number 1 last year and was fairly straightforward. Key was to heat up the engine first so everything came out easily. Also make sure everything was impeccably clean and don't go overboard on the torque when putting it back together.

That said, this might be the end for my Vito as I'm getting sick of taking it to pieces!

 

[wu56Shoozz]

You Tube may be your friend her, may be worth a look see.

 

[StMarks]

Cheers for the replies. I'll get out tomorrow and have a look at how to remove the bulkhead.

Please let us know how you get on.?

 

[BloodSexMagik]

So its definitely injector 3 as can see smoke coming from it if I shine a light. Removing the bulkhead looks doable, just a few screw/plastic rivets and it should come away. It will afford a little more room but still won't be ideal - better than an engine out job. Plan will be to get the engine nice and hot and remove the injector before removing the bulkhead but not all the way. Then remove bulkhead and injector fully, clean everything up and reseat it with a new washer and bolt.

Not going to have time to do it this weekend so it's pencilled in for next friday and I will just have to drive it as little as possible until then. I will try and take photos of the job and do a write up on here if that would be helpful to someone.

 

[BloodSexMagik]

Got the job done on Saturday. Predictably forgot to take many photos (think I managed one and it doesn't really show anything) but I'll describe the process for anyone interested in fixing it themselves. As stated in thread title this is for a Vito 111CDI but is probably applicable to most CDI engines. I'd recommend having a read of this also - http://www.mercedes.gen.in/mercedes-diesel-injector-advice-sprinter-others/ - as it describes the process well.

Firstly you'll need to buy some parts from Mercedes:
-Tub of high temperature grease
-Stretch bolt for retaining the injector*
-Injector seal/washer**

*Please do not be tempted to reuse the bolt. It is a stretch bolt and is one use. If you reuse it you are asking for things to snap/strip threads and get into a world of pain you want to avoid.
**Discussion here http://www.mercedes.gen.in/mercedes-cdi-injector-leak-honda-washerseal-alternative/ reckons you have more luck with the slightly thicker and softer Honda injector seal/washer. He explains why in that post and I agree with his reasoning so have used the Honda part instead of the Mercedes in both replacements I have performed.

This amounts to roughly ~£20 from memory so not expensive. I will add part numbers when I get a chance.

-Firstly I ran the engine for 20 minutes to get everything nice and toasty. This aids with removing the injector as everything expands. I then shut it off, disconnected the air filter box (stuffing a rag down the intake pipe to stop anything getting in) and then removed the steel fuel line running to the leaking injector. I fashioned a plug for the end of it to stop dirt getting into it and then moved it out of the way by loosening the nut that attaches it to the common rail. I then disconnected the leak off line by removing the metal clip and then popping it off the top of the injector with a screwdriver. I also disconnected the leak off from the forward two injectors to give more room to work and plugged the top of these with paper towel also. The electrical plug will also need disconnecting from the top of the injector.

- Now remove the T40 injector retaining bolt. Once out (shouldn't take much effort) I removed the retaining clamp, which will be reused later, and then proceeded to gently move the injector from side to side. If it's been leaking for a while this may be quite difficult so I would get a large spanner that fits over the injector and gently work it back and forth to loosen it up. You're basically rotating the injector in the hole. Be very careful not to use too much force as you can snap the heads off of them. Apply the turning pressure as low on the injector head as you can. With any luck it should move back and forth like mine which means that it isn't welded in.

-At this point I removed the bulkhead from above the engine to get more room to work. This was achieved by removing the wiper arms, undoing a few bolts and plastic rivets(more like snapping them, pieces of ****), removing a couple of bits of foam, removing the pollen filter retaining strap and then unclipping the top plastic piece from the windscreen and manoeuvring out. I then removed the wiper motor assembly and then finally the metal bulkhead which was held in with far too many bolts (I'm not sure where they thought it was going to go?). Remember to take the bolt that attaches the brake fluid top up reservoir to this piece off and unclip the washer fluid hose also. Then just lift the metal tray away.

-Now I had room to work I got started on removing the injector. I got my large spanner and began to rotate the injector back and forth applying upward pressure with my other hand at the same time. I would be wary of using any kind of lever against the head as I have seen stories of people cracking them. Around five minutes of rotating and pulling up with my hand and the injector came free. Set it aside and don't touch the nozzle with anything. I used a piece of wire with a hook bent in to retrieve the old washer/seal from the bottom of the hole. Bit of a fiddle but it'll come out.

-Next I made a couple of plugs from bits of wire with paper towel wrapped around them and plugged the injector hole and the bolt hole. Then I got a hoover (don't use the house one if you value your life/wife) and duct taped a bit of pipe to it. Using this and a screw driver I carefully chipped away at the black carbon deposits that had built up and hoovered them up as I went. The best solvent I have found to deal with any stubborn bits is Carb Cleaner so I used this to clean the top of the engine until it was spotless (ish).

-Remove the bolt hole plug and get the hoover pipe down that too. Either use an extra long tap or cut a notch into the old stretch bolt (I did this) to run it down the hole a few times and clear the thread out. It's worth taking time over this until its definitely clean as these threads are a weak point. I continually ran the notched bolt followed by the hoover until I was sure it was clean. You could use some carb cleaner down here too if there is a lot of coke build up. Refit the plug.

-Remove the injector hole plug and get the hoover down that. Using a mirror and light (be imaginative) look at the injector seat down the hole. It needs cleaning up to reseat a new seal against. I purchased a cheapish seal cutting kit from amazon and it was useless - the cutters didn't actually reach the seat - but I think there are better ones available. What I did was super glue a piece of abrasive paper to the end of a chopstick and then polished the seat to a nice shine. You want to get it as clean and smooth as possible.

-Now clean up the injector body itself with a screwdriver to carefully chip away at large build-ups/spray some carb cleaner on a rag and wipe the injector body with it. Don't touch the nozzle.

-Get your new injector washer/seal and put a dab of the special grease on it and slide it onto the injector - the grease should hold it in place. Smear the injector body with grease and take the injector clamp that you removed earlier (you can clean this up with carb cleaner too). Manoeuvre the injector carefully into the hole (check orientation) and attach the clamp to it - make sure the hole in the bottom of the clamp fits into the dimple on the engine. Now put your new stretch bolt in and tighten it up with fingers. Now pray to whatever god you believe in and get your torque wrench ready to tighten the bolt. See the Mercedes.gen.in article linked above but I subscribe to the tighten to 7Nm + 90deg school of thought (rather than 7Nm+90+90 - bit too tense for me, as I said these threads are a weak point). Nip it up to 7Nm then add in a quarter turn.

-That's pretty much it, refit the fuel pipes/electrical connector. Take the rag out of the air intake and fire it up, should start easily and then you can check the injector to see if it's still chuffing. If not reassemble the bulkhead in reverse order and you should be good to go.

Bit long winded and sorry if I've missed anything but hopefully it's of use to someone. Any questions just ask.

 

[StMarks]

Good work there fella, did removing the bulkhead give much more room to work for you.?

 

[BloodSexMagik]

Yeah, definitely. Injector 3 was fine to replace and I reckon it would give you enough room to do injector 4 too, it'd be tight but preferable to removing the engine (i'll probably find out at some point!)