W163 ML270 refitting injector problem

[Down.Side]

Hi Everyone

I recently bought a 2003 ML 270cdi with 160,000 miles on the clock and it had a couple of blowing injectors (three and four if counting from the front) - the dreaded "black death"!

After reading the threads already on here (Very useful too, thankyou!) I decided that the removal / refurb / replace washer and refit was something I could have a crack at with my limited skills and knowledge.

I bought a set of new copper washers and bolts off ebay, and had a go.

Anyway, to cut a long story short, I ended up stripping one of the internal threads so will need to helicoil it to repair, but the main problem I'm having is this :

When I removed the 2nd dodgy injector, after cleaning it up and greasing it, I then used the old bolt to try to clean the thread before I refitted the injector with a new bolt. Howver, the new bolt - and even the old one will now not go deep enough into the hole to screw the clamp down properly. Its as though the hole is suddenly shallower than it was???

Using a torch to shine down the hole, it does look like this is the case - it looks like metal but I have not snapped a bolt or anything like that.

Does any one have any ideas how has this happened and what has caused it?

is it going to be a case of removing all of the remaining injectors, the cam cover and have a good fiddle about or am I doing (or not doing) something obvious?

Many thanks in advance

Glyn

 

[jamesfuller]

I had this problem on my Ml a few years back. I never actually found what the problem was. It was a tiny amount, it just needed to tighten down another half a mm or so. I put a washer under the bolt head and it was fine.
But i'm not suggesting this is the correct way to go about it, it just got me out of trouble.

When I carried out the lovely task of removing all that carbon, I also cleaned up the seats where the copper washers sit (I borrowed the kit from a Garage up the road)
as they told me it would still blow if I didn't do something with them.