Strange yellow goo from CDI injectors

[stumo]

I have a ML270 CDI and injectors 1 and 4 have yellow gooey stuff coming from/around them. It is like the consistency of vasolene, and is ejected up onto the underside of the plastic engine cover and all around the injectors.

Please does anyone have any ideas as to what I can do?

 

[dave.robbo]

Could it just be spray grease that was squirted to assist in the assembly of the engine/injectors?

 

[stumo]

Could it just be spray grease that was squirted to assist in the assembly of the engine/injectors?

Thats what I thought initially, so I cleaned it all off. But after checking again after only 200km (120 miles), it is back again. So it is definately coming from somewhere. ie. I specifically cleaned the undeside of the engine cover, and now it has the goo in a kind of single spot spray pattern above inj 1 and 4.

The car is new to me, and it supposedly had "new injectors" 30,000km ago - but it is just a note in the service book,(no receipt) so I find that a bit hard to believe considering the costs involved, not to mention why it would even need new injectors. Anyway, it may be related to the goo problem - any more takers???

 

[Kevin Gardiner]

the grease your seeing is assembly grease from when the injectors were refitted.
i expect when the injectors were replaced the seat weren't cleaned properly allowing the exhaust gases to blow the grease up past the injector.

 

[dava]

I would have sniff of it it could be diesel, under some conditions it turns waxy and this might suggest a leaking seal.

 

[exeng]

leaking injectors

The easy way to see if injectors are leaking is to pour water onto the head while engine running you will see bubbles if they are leaking which i suspect they are the seats have to be spotless on refitment

 

[Cnics]

You ask why they'd be replaced. I think there were alot of injector issues around the 2002 / 2003 years on the CDI's

 

[stumo]

The easy way to see if injectors are leaking is to pour water onto the head while engine running you will see bubbles if they are leaking which i suspect they are the seats have to be spotless on refitment

Excellent, I was hoping I would be able to try something like this - I was thinking about using a soapy water mixture like when finding exhaust leaks.

Anyway, regardless of what the goo actually is, it seems I will need to find out and fix wherever it is leaking from. I will have another look probably next week when I have the engine cover off for an oil and filter change. I will report back then.

Thanks for all the help so far.

 

[stumo]

the grease your seeing is assembly grease from when the injectors were refitted.
i expect when the injectors were replaced the seat weren't cleaned properly allowing the exhaust gases to blow the grease up past the injector.

Ok I have checked with soapy water now, and there is a blow-by leak at inj 1 and 4. So my next questions are....

1. Should I pull all 5 injectors and re-seat them (cleaning/refacing as required) with new washers and bolts? The reason I ask is that it has only been 20k km ago that they were "replaced" and whoever did it might not have done a good job since 2 are leaking already.

2. Should I use new clamps as well? (The car has done over 235k km)

3. Any other tips/tricks that could be useful for the replacement procedure? I'm hoping the injectors will just lift out, since there is absolutely no carbon around any of them yet.

Cheers for all the help so far, this forum is excellent.

 

[dragon]

I found some around the joints of the MAFF. Will it affect the performance of the MAFF? The MAFF looks clean inside. Currently the engine hesitates when I accelerate.

 

[stumo]

I found some around the joints of the MAFF. Will it affect the performance of the MAFF? The MAFF looks clean inside. Currently the engine hesitates when I accelerate.

The answer to your MAF issue may be found here.

 

[dragon]

The answer to your MAF issue may be found here.

Why are you taking me to Thread hijacking wiki link?

 

[kebo57]

I have a ML270 CDI and injectors 1 and 4 have yellow gooey stuff coming from/around them. It is like the consistency of vasolene, and is ejected up onto the underside of the plastic engine cover and all around the injectors.

Please does anyone have any ideas as to what I can do?

Hi I have had the same problem / same motor
see my thread below
http://forums.mercedesclub.org.uk/showthread.php?t=35511

Like you say "it has only been 20k km ago that they were replaced"

So you might have difficulties with extraction & you will need to make a good job of the mating surface
Kevin

 

[stumo]

Well I had a go at the injectors yesterday, with partial success...

I couldn't get no1 out, my special "Mercedes CDI" puller tool I got off ebay wouldn't fit down into the recess in front of the injector. Also the thread tap that came in the puller kit (for the clamp bolt holes) was too thin. So that was 100 quid not well spent at all!!! The injector would not budge at all with my limited attempts at freeing it, I could see some black lava poking out just at the joint between the head and injector.

I might grind away some of the injector puller fork part so that it will fit before I try again. I had limited time and no grinder yeasterday.

Inj4 came out basically by hand after giving it a twist each way with screwdriver levering. I ran it through my small untrasonic cleaner with quite good results on the injector tip (see here http://forums.mercedesclub.org.uk/showthread.php?t=42301), then cleaned the rest of the injector shaft with a brass wire brush. Applied the MB special grease. Cleaned the hole in the head with a piece of green scotch pad wrapped around a screwdriver and WD40. Re-torqued with a new bolt and new washer. To get the old washer out I just free'd it with a screwdriver then used a long piece of wire with a hook.

Back on the stuck inj1 I just put a new bolt in and gave it a few good blows with a hammer and drift before torquing fully (7nm + 90deg + 90deg) and it seems to have stopped the leak (for now).

I did want to ask if it is true that if you take the injector apart to connect a certain type of puller adaptor, do you then need to buy a new injector?

 

[Bill312D]

i was talking to my indy about this with my vito ad he says he has a special tool for removing injectors, but if he has to use it the injector is rendered useless.

 

[kebo57]

I did want to ask if it is true that if you take the injector apart to connect a certain type of puller adaptor, do you then need to buy a new injector?

The answer is no the injector can be put back together, but I've never done it
I spoke to a guy on this forum EXENG he does the extraction that way for MB dealership when they can't remove them.
The No 1 injector is the one with the least Clarence regarding getting a puller in.
Thats the one I made my puller to suit. you could of borrowed it our I could have come round & had a crack at it my self but your in Australia.

Kevin