300 Tdi Rebuild

ir\e ?
So if seals are not right, it can blow back in to the exhaust flow and straight out the back?

Al2O3 said:

ir\e ?
So if seals are not right, it can blow back in to the exhaust flow and straight out the back?

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yes, or out of cold side in to the cylinders, you allways find intercooler and hoses are wet but you shoudnt notice oil loss over the short term

jamesmartin said:

yes, or out of cold side in to the cylinders, you allways find intercooler and hoses are wet but you shoudnt notice oil loss over the short term

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If it comes through the cold side it must burn as it goes through the cylinders, surely?? My hoses look very wet for new hoses!

Al2O3 said:

If it comes through the cold side it must burn as it goes through the cylinders, surely?? My hoses look very wet for new hoses!

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yes it does, they allways do thats why you have to see what is actually passing out of the turbo direct

I need to try and rule out the turbo, so I'll try the various tests at the weekend. ie investigating how much oil is coming through the breather or from the turbo. I've got a lot of oil in those pipes (well it seems a lot to me) so it has to be coming from one of those sources.

I don't want another bloody runaway

it has to be bad for that and then it doesnt allways happen

jamesmartin said:

it has to be bad for that and then it doesnt allways happen

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Phew!
Cheers, James. I'll get there eventually.

Next update.
Yesterday, I spoke to the company I bought the turbo off. I told them I thought it was passing a lot of oil. They asked me to check the oil return from the turbo to see if it was blocked as this would cause the oil to be forced through the seals. I was confident that it was fine as I had checked the oil flow on installation with the outlet pipe in a milk carton to catch oil as it came out. Oil was coming out of it freely back then.
Anyway, took it off this morning. Pipe was fine.

It goes on straight with no kinks.
I cleaned the I/C pipes.
Elbow from the turbo

Top of I/C to inlet manifold

Air inlet to turbo

Hard to tell with it being black, but that has been cleaned with brake cleaner and is oil free.
Inlet manifold

Put it all back together and took it for a spin up the road. Drove it hard taking it up to nearly 60mph in 4th before slipping in to 5th. Kept it at 60mph even on inclines. Engine was pulling well. Did 28 miles by the time I got home ant then checked the pipes.
Elbow from turbo.

Looking in from other end of the elbow pipe.

I/C to inlet manifold.

Not such a clear picture but there is a fair bit of oil there.
Inlet manifold.

Air inlet to turbo

You can't tell, but it's dry, clean and free of oil.
To me, that looks like a lot of oil that has come through the turbo in 28 miles.
What do you reckon?
I suppose the next thing is to try to rig up some way of catching the oil coming out.

Set this up and set it away ticking over on the drive.

Noticed a clickety chirping sound while I was stood there.
I couldn't tell where it was coming from. Everywhere I put my ear I could hear it.

Checked tappet clearances. Ok.
Put the rocker cover back on and turned it over with the socket wrench still attached to the crank nut.
As soon as I heard a rattle I turned the key back. Fortunately she didn't fire up, but the wrench handle took a bit out of the bottom of the radiator cowl and badly bent one of the power steering pipes. What an idiot IIRC they are expensive anorl. I considered changing them when I rebuilt the body, cos they were very rusty. Think I decided not to for the time being because of the cost. I'll have to look the part number up. And keep my fingers crossed it doesn't start to leak.

Started it up properly without the socket! Chirping still there and I suspect the alternator.

What a day! Any thoughts on my turbo and now that noise?

Ooh, nearly forgot to say. My brief test with the milk carton revealed no oil showing. However, I know there is a load of oil coming through, it was only for a minute or two at tick over, so I reckon not comparable to 28 miles at 60mph.

As promised Al....here are a couple of photos of my inlet manifold and top IC hose....difficult to see, but these were last cleaned when I did the Core Plugs a couple of months ago.....

You are a star. A couple of months ago..................how many miles do you reckon?
Yours doesn't smoke though?

Al2O3 said:

You are a star. A couple of months ago..................how many miles do you reckon?
Yours doesn't smoke though?

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Just a little puff when foot first planted.....if revved over and over she can start to puff a bit of black/white smoke....but that could be expected as the manifold pressure is low and you are pumping a lot of diesel into the cylinders.....this is where pump tuning adjustments can help - the Star wheel, the boost pin and the smoke screw.

On start she gives a little puff of black, tanking up a hill pulling hard and she'll give a bit of a black haze but not clouds of soot....

Runs fine, and there is quite a bit of oil in the pipes.

I'd say she has done 1200-1500 miles in the last couple of months.

Saint.V8 said:

Just a little puff when foot first planted.....if revved over and over she can start to puff a bit of black/white smoke....but that could be expected as the manifold pressure is low and you are pumping a lot of diesel into the cylinders.....this is where pump tuning adjustments can help - the Star wheel, the boost pin and the smoke screw.

On start she gives a little puff of black, tanking up a hill pulling hard and she'll give a bit of a black haze but not clouds of soot....

Runs fine, and there is quite a bit of oil in the pipes.

I'd say she has done 1200-1500 miles in the last couple of months.

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Hmmm........... mine smokes more than that. At the moment, I think mine is oil burn rather than diesel not combusting properly. This is backed up by the amount of oil I'm using. I put another litre in today!

So another litre - and how many miles??

Don't get me wrong, mine can puff hard and smoke....but it is more white and black or grey....little oil is burned in mine as the level doesn't drop as fast as yours seems too.....maybe 1/2 litre every 8-10 weeks (about 2k miles)

Saint.V8 said:

So another litre - and how many miles??

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263 miles

And it isn't coming out the bottom and being blown over the underside or burnt on the exhaust??

Saint.V8 said:

And it isn't coming out the bottom and being blown over the underside or burnt on the exhaust??

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Clean as a whistle underneath. No leaks from anywhere, which is a positive I suppose.
James is probably going to be right about the honing. But,
1. I can't get my head around the physics with the compression being so good.
2. I don't want to believe it

Al2O3 said:

Clean as a whistle underneath. No leaks from anywhere, which is a positive I suppose.
James is probably going to be right about the honing. But,
1. I can't get my head around the physics with the compression being so good.
2. I don't want to believe it

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As James alluded to:

The boring of the cylinders creates a screw thread, if this is not honed out, the minute screw thread can create a helical path for the oil to travel up via both capillary action and also when the piston goes up and down it draws oil and drives it up the screw thread into the combustion chamber.

Compression results will remain good as the oil is acting as the seal in the micro-grooves and seals against the piston rings.

The honing pattern in a cross shape, allows oil to be drawn into the honing grooves and stay there to line the bores to allow the pistons to slide, but they don't create a helical screw thread and as such can't be drawn all the way up into the chamber as the next micro-groove they encounter is one going the opposite way and the oil remains where it is and doesn't have a 'path' into the chamber - like the Archimedes screw,

Saint.V8 said:

As James alluded to:

The boring of the cylinders creates a screw thread, if this is not honed out, the minute screw thread can create a helical path for the oil to travel up via both capillary action and also when the piston goes up and down it draws oil and drives it up the screw thread into the combustion chamber.

Compression results will remain good as the oil is acting as the seal in the micro-grooves and seals against the piston rings.

The honing pattern in a cross shape, allows oil to be drawn into the honing grooves and stay there to line the bores to allow the pistons to slide, but they don't create a helical screw thread and as such can't be drawn all the way up into the chamber as the next micro-groove they encounter is one going the opposite way and the oil remains where it is and doesn't have a 'path' into the chamber - like the Archimedes screw,

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Hmm..........that's not good news then. I'm still stubbornly holding out though.............. nobody likes a quitter