Glazed Black Build-up Under Injector - 2.5NA

Greetings,

I've just found a build-up underneath one of my injectors. It's black and some of it's a bit rubbery, and some a bit more brittle and sooty. It's got a glazed shiny finish to it. I'm thinking it's diesel leaking, but I didn't know it would look like that. Anyway, I need to replace one of the washers in the banjo bolt on the return rail above it, but I think the main problem seems to be coming from beneath the injector. I've been looking for injector seals, but I don't know/can't find them. Anyone know what parts they are, part no. etc?

Cheers. Tom.

Is this visible on the outside of the engine?

If so it is likely to be a tiny gas-leak from the copper washer between the injector body and the seat in the cylinder head.

You want to fix this soon because the injector may become VERY stuck. I may already be VERY STUCK.

All you need is 4 new copper washers of the correct size, and a little red Hermetite is always good.

Easy job. El Zed - Two Spaniard job.
One for the injector pipe nuts and one for the clamp nuts.
And probably a hammer and a pry-bar to persuade them to come up.

CharlesY

Yes, it's very visible on the outside of the engine, but can be picked off quite easily. I may have a lead on some copper washers already (thanks Sypher )

Would you put the Hermetite (or Hylotyte) around the washer? On both sides?

Thanks for the advice. I'll try and get this done this weekend!

tombardier said:

Yes, it's very visible on the outside of the engine, but can be picked off quite easily. I may have a lead on some copper washers already (thanks Sypher )

Would you put the Hermetite (or Hylotyte) around the washer? On both sides?

Thanks for the advice. I'll try and get this done this weekend!

Click to expand...

CLEANLINESS is the answer here.

Plug the injector inlet boss, and make sure you don't damage it in any way.

Use a stiff wire brush on the injectors, tips and all, till there is NO carbon gunge on them. DO NOT USE EMERY OR SANDPAPER!
Wipe them spotlessly clean at the tip end, and make sure the flat surface the copper washer sits on is ABSOLUTELY clean, right into the inner corner edge.

This is what I do next. Others will be experts and will know better.

Clean the hole in the head where the injector fits. If some crap falls in, forget it. It won't last long in there. Use a little rag wetted with petrol to clean the hole, and make sure the flat seat where the washer will sit is perfectly clean and dry, and no particle of crap on the seat.

Now you need a small fine perfectly flat file. Take a washer, and press it lightly but firmly onto the file near the end, and slide it ONCE up the file. This will scratch lines on the washer. Do this ONCE more but rotate the washer so that the second scratches make a criss-cross pattern on the copper. Do the same to the other side. Do all the copper washers at this stage.

Get a bit of wire and bend it to you can hang the washers on it.

Now put a LITTLE red Hermetite on your index finger, touch it with your thumb, and rub the Red Hermetite onto the washer between finger and thumb. Now hang the washer on a bit of wire till the Red H is dry. You should have a very thin smear of Red H on both sides of each washer.

The rest is the usual fitting injectors routine.

If the copper washer seals really well, there will be NO gas leaks, and therfore no carbon burned-on gunge.

It's what I do, but as I say, there will be loads of experts out there who do
things differently.

I have NEVER had an injector leak gas or get stuck after being fitted like this.

CharlesY