XANTIA HDi RUNNING ROUGH

[Skull]

Sorry JIM, while attempting to quote your post I accidentally deleted instead of quoting. Perhaps you could reinstate it MTM

Who me

[Skull]

Well the results of my inspection today ....it's fair to say that it needs more than a Cam-Follower

I can't tell from the camera orientation as it just gives a peep-hole view (edit: photos with fuel injector removed and camera inserted through the hole)

Skull's - holed piston

That looks like the final chapter @ 168K

I'm not sure whether this is a piece of the missing piston or the valve seemingly sat on a ledge or perhaps a piece held by the valve.

Skull's - piston/valve piece

This has happened sometime between the garage visit (1/2 mile away) where No. 4 was still firing (after the initial faulty core-plug and engine timing was re-set) and Jim and Mick's visit.

I know it's only a car but

[mickthemaverick]

I can't really make out what we are looking at there. Is it possible that the apparent 'bit' is from the inside of the original core plug which dropped in before the plug failed completely and worked its way to the valve during the subsequent drive home? Also the apparent 'hole' looks far too regular to be a holed piston to me, suggesting a trick of the camera's light maybe? Either way it's a head off and look properly job I'd say!!

[Skull]

Yeah Mick the camera wasn't easy to control the focus of the piston crown and in an attempt to improve the view I used the camera mirror attachment which er ... detatched inside

I don't see how the core plug would have found it's way into the combustion chamber but I think I'm still going to pull the cylinder head off but with the view that it won't be put back together ....

[mickthemaverick]

My thinking re the bit of core plug was that it came off the outside and found its way into the injector port and then dropped inside when the injector was removed.

[Skull]

Mick - Just because I lost the mirror down there the core plug wouldn't fit down there

[mickthemaverick]

I was thinking more of a flaky bit of rust off the surface of the core plug but it was only an initial reaction. Possibly the valve spring top collett or washer if there is one? One of these:

Possibilities arrowed

[Rhothgar]

I'd like to know where you inserted it...

You seem to be looking up? I can see the spring coils furthest away but cannot make out if there is a valve stem or a guide.

Some more context is required ie did you remove the cam or something else?

What Mick has identified is the top or bottom spring retainer which makes sense between without knowing what you have removed and where you inserted it, we're all guessing I think.

[Skull]

Initially I put the camera down the glow-plug hole but very poor picture of something

So I took the fuel injector out and all was revealled in the 2 pictures above of the piston crown with a chunk missing

[mickthemaverick]

If I follow you these are what I thought you were seeing and what I think you tell me you were seeing?

What I thought I was seeing

What I think you are telling me?

Am I anywhere close?

[Skull]

Am I anywhere close?

Not really ..... Valve Spring looks intact just the follower has broken and I believe the valve has broke the top of the piston (the valve head may have even broke off and fell through the hole it made in it's bid for freedom) ....

[Rhothgar]

If I follow you these are what I thought you were seeing and what I think you tell me you were seeing?





Am I anywhere close?

What is/was throwing me is where you say valve. I thought it was too because you think you can see the spring coils.

But I can also now see Skull’s line of thinking.

If we can drag up a picture of the piston from the parts catalogue all might become clearer.

The round shiny bit could be the top of the piston with the surrounding skirt and between them is a volume for compressing the diesel?

[Rhothgar]

If there was a hole in the piston there would be NO compression at all.

[ekjdm14]

Really doesn't look like a bad piston to my eye, looks like a bit of liquid down the bottom & an otherwise healthy looking piston crown.

Academic now since there's a mirror stuck in there, but I honestly don't see anything wrong & still think it could've been a random rocker failure.

The circular area in the centre is the combustion chamber in the piston. I've a set of HDi pistons/rods somewhere if we need a clearer photo for reference? I think the "missing chunk" is liquid diesel from being unable to fire due to no valve opening.

[Rhothgar]

This is what you are seeing.

I thought it might be a pyramidal cone.

I don’t think you have a holed piston but it does look as though something has bounced around a little on top of it if you look to the right of your photo.

You cannot easily get the inlet manifold and exhaust off so I would remove cam and test compression on the cylinder.