300 Tdi Rebuild

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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
 
Goc3k said:
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
Click to expand...

To be honest I can't follow all of that. :oops: Do you think the oil is going out via the hot side of the turbo and out through the exhaust?
 
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
 
Goc3k said:
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
Click to expand...

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 :rolleyes:

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?
 
@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 :eek:
 
Al2O3 said:
This oil must also get blown in to the combustion chambers from the manifold, but at what rate is the puzzle. To me anyway
Click to expand...

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.

Al2O3 said:
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?
Click to expand...

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
 
Al2O3 said:
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?
Click to expand...

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.

Goc3k said:
combustion chamber and into the crankcase
Click to expand...

Also, this sentence is nonsense - late posting errors in action :oops: 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.
 
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Goc3k said:
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
Click to expand...

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

Goc3k said:
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.
Click to expand...
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.
IC to Inlet Manifold Pipe after 650 miles.JPG

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

Inside the bottom pipe of the IC
IMG_6432.JPG

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. :(
 
Al2O3 said:
Oil in the IC to inlet manifold pipe.
Click to expand...
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?

Al2O3 said:
I think 50ml or less is a good suggestion for a fair test
Click to expand...
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.

Al2O3 said:
It's not long since I put the 15w40 mineral oil in, but it's going black now
Click to expand...
The sump oil you meant? How many miles are on the 15-40?

Al2O3 said:
like James Martin, you think it's passing the piston rings and getting burnt due to poor honing?
Click to expand...
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?
 
Goc3k said:
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?
Click to expand...
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.


Goc3k said:
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.
Click to expand...
It can't be massively different. It'll be an interesting experiment. :)


Goc3k said:
The sump oil you meant? How many miles are on the 15-40?
Click to expand...
985


Goc3k said:
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?
Click to expand...
Well, I'm not completely out of hope yet :rolleyes::(:)
I'll PM you the name.
 
Al2O3 said:
All three pictures were taken 650 miles after all was cleaned.
Click to expand...
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?
 
Goc3k said:
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?
Click to expand...
I'll check when I get home at the weekend.
 
@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 :rolleyes:
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? :)
 
Al2O3 said:
Need to go out to see my sons new flat. I suspect it'll cost me somewhere along the line :rolleyes:
Click to expand...
Sounds about right!

Al2O3 said:
Hyperthetically speaking, would you buy my turbo off me second hand, having seen the pictures of the oil it passes? :)
Click to expand...
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.
 
Kwakerman said:
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!
Click to expand...
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 :)
 
Kwakerman said:
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!
Click to expand...
Just took the pipe off the top of the cyclone and stuck my finger in it.
IMG_0111.JPG

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 :rolleyes:
 
Al2O3 said:
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 :rolleyes:
Click to expand...
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?
 
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