300 Tdi Rebuild

[Goc3k]

The pressure drop effect separates the oil from the air rather than the oil condensing as it hits the IC. The oil vapour starts to condense immediately after it is forced out of the combustion chamber and into the crankcase (via blowby, oil passing from the turbo will condense as soon as it hits the compressor housing, or blow straight out the exhaust via the turbine seal), even before reaching the intake plumbing (massive temp drop, like when you breathe out on a frosty morning and the water in your breath condenses near instantly) , as such - oil vapour than drops out and becomes trapped in the intake system / starts to pool will never be picked back up by the intake charge again, as the temperature within the intake cannot get high enough to vaporize the collected oil residue (temperature in the IC is less than 200C-250C all the time). There is a degree of evaporation that occurs of course, and that is what stops the system on a healthy engine eventually filling with oily residue. (passage of "leaked" oil is less than the rate of evaporation)

Hence checking for pooling (or the lack of) is a good test - if anything it would be nice to see some pooling as that might help the diagnosis become more concrete

 

[Al2O3]

The pressure drop effect separates the oil from the air rather than the oil condensing as it hits the IC. The oil vapour starts to condense immediately after it is forced out of the combustion chamber and into the crankcase (via blowby, oil passing from the turbo will condense as soon as it hits the compressor housing, or blow straight out the exhaust via the turbine seal), even before reaching the intake plumbing (massive temp drop, like when you breathe out on a frosty morning and the water in your breath condenses near instantly) , as such - oil vapour than drops out and becomes trapped in the intake system / starts to pool will never be picked back up by the intake charge again, as the temperature within the intake cannot get high enough to vaporize the collected oil residue (temperature in the IC is less than 200C-250C all the time). There is a degree of evaporation that occurs of course, and that is what stops the system on a healthy engine eventually filling with oily residue. (passage of "leaked" oil is less than the rate of evaporation)

Hence checking for pooling (or the lack of) is a good test - if anything it would be nice to see some pooling as that might help the diagnosis become more concrete

To be honest I can't follow all of that. Do you think the oil is going out via the hot side of the turbo and out through the exhaust?

 

[Goc3k]

Suppose it wasn't the best explanation, think the comparisons make it harder to read! The short version was = excessive leakage into the intake either via turbo or pcv will cause pooling in the lowest part of the system, eventually.

Aye it is entirely possible it is leaking straight out the hot side rather than the compressor side, which would manifest as smelly light white smoke (possibly moreso on boost but not necessarily), which a mate driving behind you might be able to see / smell

 

[Al2O3]

Suppose it wasn't the best explanation, think the comparisons make it harder to read! The short version was = excessive leakage into the intake either via turbo or pcv will cause pooling in the lowest part of the system, eventually.

Aye it is entirely possible it is leaking straight out the hot side rather than the compressor side, which would manifest as smelly light white smoke (possibly moreso on boost but not necessarily), which a mate driving behind you might be able to see / smell

I appreciate all of this feed back as it's getting me to think about the problem from angles I haven't thought of and so I'm learning all of the time.
A thought - the inside of my inlet manifold is oily. This is to be expected, as I've shown pictures of the oil pooling in the inlet pipe, up against the lip of the inlet manifold. So, it follows, that the oil will be blown over the lip and in to the manifold. This oil must also get blown in to the combustion chambers from the manifold, but at what rate is the puzzle. To me anyway

Question - to someone driving behind- what differences might there be to the smell and visual appearance of oil passing the turbo seals straight in to the exhaust. And oil going through the IC or past the piston rings and being burned before coming out the exhaust?

 

[Al2O3]

@Goc3k
I'm trying to think of this a different way.
Imagine taking the top hose off the IC and pouring 200ml of oil in to the IC. Or putting it in to the bottom hose. Then taking the Landy for a 250 mile run. Would that oil be lying in the bottom of the IC or would it be blown up through the IC, through the manifold and burnt?
I could experiment, I suppose

 

[Goc3k]

This oil must also get blown in to the combustion chambers from the manifold, but at what rate is the puzzle. To me anyway

The oil vapour that remains suspended will make up 99% of what is burnt, the stuff that builds up and is what is visible upon inspection will for the most part remain as buildup and never end-up being drawn into the engine under usual circumstances, if it never builds up to more than "a bit oily" then that is acceptable.

Question - to someone driving behind- what differences might there be to the smell and visual appearance of oil passing the turbo seals straight in to the exhaust. And oil going through the IC or past the piston rings and being burned before coming out the exhaust?

Oil that escapes the oil control rings on the hot side of the turbo will flow straight into the exhaust manifold and blow out the exhaust, unburnt - this will be more visible whitish smoke / haze, whereas oil that has actually been burnt in the combustion chamber in small amounts will generally be harder to see or a light grey from the exhaust, but will smell slightly more acrid vs the smell of just burnt diesel. Both the smells are hard to explain really, will be easier to see the smoke at dusk with lights on also

 

[Goc3k]

Imagine taking the top hose off the IC and pouring 200ml of oil in to the IC. Or putting it in to the bottom hose. Then taking the Landy for a 250 mile run. Would that oil be lying in the bottom of the IC or would it be blown up through the IC, through the manifold and burnt?

As I understand it, if you were to do this within a system working as intended, with say 50mls (as 200mls is loads, and some would get churned up and sucked in just by turbulence of the sheer volume in the small 300tdi IC) - then it would almost certainly still all be there after only 250 miles. Possibly it would clear after a good few thousand miles?

As a direct comparison I had a 405 with a mildly shagged turbo a few years back, took about a thousand miles for a few teaspoons to build up in the lower left corner of the IC after being cleaned out, but it would never build past that amount, and once i'd put a lower mileage scrap turbo on it stopped collecting it entirely.

combustion chamber and into the crankcase

Also, this sentence is nonsense - late posting errors in action Should read:

The pressure drop effect separates the oil from the air rather than the oil condensing as it hits the IC.

The oil vapour starts to condense immediately after it escapes past the PCV / compressor housing of the turbo. Heavier elements within the oil vapour then drop out of the stream further down and become trapped in the intake system.

This residue will never be picked back up by the intake charge again, as the temperatures required to vapourize oil will never occur within the intake.

 

[Al2O3]

The oil vapour that remains suspended will make up 99% of what is burnt, the stuff that builds up and is what is visible upon inspection will for the most part remain as buildup and never end-up being drawn into the engine under usual circumstances, if it never builds up to more than "a bit oily" then that is acceptable.

Oil that escapes the oil control rings on the hot side of the turbo will flow straight into the exhaust manifold and blow out the exhaust, unburnt - this will be more visible whitish smoke / haze, whereas oil that has actually been burnt in the combustion chamber in small amounts will generally be harder to see or a light grey from the exhaust, but will smell slightly more acrid vs the smell of just burnt diesel. Both the smells are hard to explain really, will be easier to see the smoke at dusk with lights on also

I'll get the Mrs to drive the Landy while I follow her in the Mondy.

As I understand it, if you were to do this within a system working as intended, with say 50mls (as 200mls is loads, and some would get churned up and sucked in just by turbulence of the sheer volume in the small 300tdi IC) - then it would almost certainly still all be there after only 250 miles. Possibly it would clear after a good few thousand miles?

As a direct comparison I had a 405 with a mildly shagged turbo a few years back, took about a thousand miles for a few teaspoons to build up in the lower left corner of the IC after being cleaned out, but it would never build past that amount, and once i'd put a lower mileage scrap turbo on it stopped collecting it entirely.

While you were writing your last post I was looking at my past pictures. The following show the oil being passed by the first recon turbo I put on following the rebuild.
Oil in the IC to inlet manifold pipe.

The first turbo was passing a lot more oil
My newly cleaned out, nice and shiny inlet manifold.

Inside the bottom pipe of the IC

I think I'll try putting some clean oil in the bottom of the IC at the weekend and see what happens. I think 50ml or less is a good suggestion for a fair test. It's not long since I put the 15w40 mineral oil in, but it's going black now. The new oil might show against it and perhaps help see what's going on. It's all very interesting.

I'm presuming, like James Martin, you think it's passing the piston rings and getting burnt due to poor honing? I fear you're both probably right, but I have to clutch at straws and investigate other possibilities.

EDIT
Obviously, I'm not convinced that the turbo reconditioning company were crash hot or were using top quality parts.

 

[Goc3k]

Oil in the IC to inlet manifold pipe.

Aye that first pic is "not so good" levels, but the pic of the bottom of the IC is with the new turbo on correct? How many miles of collection occurred before taking that photo?

I think 50ml or less is a good suggestion for a fair test

Haha, can't say i've ever heard of that being tried - will be interesting to see if it clears I suppose. And also the chemistry, as no doubt fresh oil has a lower specific gravity than the stuff that is dropped from oil vapour, and thus may be picked up again more easily.

It's not long since I put the 15w40 mineral oil in, but it's going black now

The sump oil you meant? How many miles are on the 15-40?

like James Martin, you think it's passing the piston rings and getting burnt due to poor honing?

That is the most likely case, be it a poor hone or not run in quite right - primarily as it seems the problem isn't worsening / is slightly better than it was? Bad oil control seals in the turbo would only get worse, and fairly rapidly if they were bad. What company reconned the turbo out of curiosity?

 

[Al2O3]

Aye that first pic is "not so good" levels, but the pic of the bottom of the IC is with the new turbo on correct? How many miles of collection occurred before taking that photo?

No, that picture was with the old turbo that was passing a lot of oil. All three pictures were taken 650 miles after all was cleaned.

Haha, can't say i've ever heard of that being tried - will be interesting to see if it clears I suppose. And also the chemistry, as no doubt fresh oil has a lower specific gravity than the stuff that is dropped from oil vapour, and thus may be picked up again more easily.

It can't be massively different. It'll be an interesting experiment.

The sump oil you meant? How many miles are on the 15-40?

985

That is the most likely case, be it a poor hone or not run in quite right - primarily as it seems the problem isn't worsening / is slightly better than it was? Bad oil control seals in the turbo would only get worse, and fairly rapidly if they were bad. What company reconned the turbo out of curiosity?

Well, I'm not completely out of hope yet
I'll PM you the name.

 

[Goc3k]

All three pictures were taken 650 miles after all was cleaned.

Oh, that's actually rather a lot then for such a short distance post cleaning. Should be just an oily haze with a few drops collected after such a short distance

985 miles before blackening isn't very far on a rebuilt engine that gets fresh oil constantly, got a pic of the dipstick / oil clarity? Does the oil smell of just oil?

 

[Al2O3]

Oh, that's actually rather a lot then for such a short distance post cleaning. Should be just an oily haze with a few drops collected after such a short distance

985 miles before blackening isn't very far on a rebuilt engine that gets fresh oil constantly, got a pic of the dipstick / oil clarity? Does the oil smell of just oil?

I'll check when I get home at the weekend.

 

[Al2O3]

@Goc3k Home now, I'll have a sniff of the oil later. Need to go out to see my sons new flat. I suspect it'll cost me somewhere along the line
Anyway, I've had a thought from a different angle so here's one for you. Hyperthetically speaking, would you buy my turbo off me second hand, having seen the pictures of the oil it passes?

 

[Goc3k]

Need to go out to see my sons new flat. I suspect it'll cost me somewhere along the line

Sounds about right!

Hyperthetically speaking, would you buy my turbo off me second hand, having seen the pictures of the oil it passes?

If I knew the turbo was the only factor causing that oil collection, then probably not, but if i was just buying that turbo off of a scrap engine and saw that buildup i'd not know it occurred over such a short time frame and probably buy it anyway. Is the EGR still connected also? looks much blacker and heavier post intercooler.

 

[Al2O3]

No, I've removed the EGR.

 

[Kwakerman]

No, I've removed the EGR.

Have you seen this, just wondering if that could be a potential cause of your oil consumption / loss? That said, I've not trawled through all these pages recently to see what state your pipes are in!

 

[Al2O3]

Have you seen this, just wondering if that could be a potential cause of your oil consumption / loss? That said, I've not trawled through all these pages recently to see what state your pipes are in!

Early on, after the engine rebuild, when I noticed the oil consumption, I tested the vent from the cyclone with a catch bottle. It remained clear. I'd installed a new cyclone too. I haven't checked it since though, so I think it's worth another look to see if there is any oil in the pipe that plugs in to the air intake. Appreciate the thought and the link to the video

 

[Al2O3]

Have you seen this, just wondering if that could be a potential cause of your oil consumption / loss? That said, I've not trawled through all these pages recently to see what state your pipes are in!

Just took the pipe off the top of the cyclone and stuck my finger in it.

Hmm, I wonder if I cleaned that pipe? Not 100% sue, but I think I did. If I did, I don't think that's looking good. Something else to investigate

 

[Kwakerman]

Just took the pipe off the top of the cyclone and stuck my finger in it.
View attachment 162936
Hmm, I wonder if I cleaned that pipe? Not 100% sue, but I think I did. If I did, I don't think that's looking good. Something else to investigate

I think you will probably end up with a finger looking like that as there is oily air moving through it. Is the pipe leading to the air intake oily?

 

[Al2O3]

I think you will probably end up with a finger looking like that as there is oily air moving through it. Is the pipe leading to the air intake oily?

Yes, there is oil in the other end of the pipe too.