Any Fluid Dynamics Experts?

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Al2O3

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I'll keep a long story short. I rebuilt my 300Tdi engine a couple of years ago and I've had trouble with the turbo blowing oil through the intercooler ever since. On to my third turbo. If you're bored and got some time on your hands you can see my engine rebuild thread in the Engines section of the forum. Anyway, the after-market oil return pipe was kinking and I thought this was creating a build up of oil causing the high pressure oil coming in to burst through the turbo seals in to the compressor side. I eventually found an original replacement return pipe. Bought another CHRA for the turbo and tried it this week. The replacement CHRA is blowing oil through straight away.
I also replaced the HP inlet pipe for a new (aftermarket) one. I'm wondering if this pipe is also not made to the exact spec of the original. So, I'm wondering if the ID of the pipe is smaller then the pressure might be higher and this might be affecting the turbo? If the pressure is higher would that mean the volumetric flow will be less and so may cancel out any potential higher pressure and so make no odds? If anyone understands this better than me I'd appreciate your thoughts. I'm clutching at straws now a bit. :rolleyes:
 
I'll keep a long story short. I rebuilt my 300Tdi engine a couple of years ago and I've had trouble with the turbo blowing oil through the intercooler ever since. On to my third turbo. If you're bored and got some time on your hands you can see my engine rebuild thread in the Engines section of the forum. Anyway, the after-market oil return pipe was kinking and I thought this was creating a build up of oil causing the high pressure oil coming in to burst through the turbo seals in to the compressor side. I eventually found an original replacement return pipe. Bought another CHRA for the turbo and tried it this week. The replacement CHRA is blowing oil through straight away.
I also replaced the HP inlet pipe for a new (aftermarket) one. I'm wondering if this pipe is also not made to the exact spec of the original. So, I'm wondering if the ID of the pipe is smaller then the pressure might be higher and this might be affecting the turbo? If the pressure is higher would that mean the volumetric flow will be less and so may cancel out any potential higher pressure and so make no odds? If anyone understands this better than me I'd appreciate your thoughts. I'm clutching at straws now a bit. :rolleyes:

Have you seen the britannica you tube video where he is searching for a reason he has oil in the pipework?


Cheers
 
I did study fluid mechanics when I did my engineering qualifications many moons ago. A very clever bloke called Bernoullie (I think I spelled that right) worked out that the volume (quantity) of a fluid flowing through a closed system was constant (ie the volume going in at one end is always the same as the volume coming out the other end). In sections of larger diameter (or cross section) the velocity falls but the pressure increases. In sections of smaller diameter the pressure falls and the velocity increases. Where the fluid exits the system (such as at the end of a hose pipe) the velocity again increases and the pressure falls to zero. People often misunderstand and mistake high velocity for high pressure, this is not the case.
In the case of your oil pipe, if the diameter is smaller than it should be then the pressure in it will be lower than it should be but the velocity through it will be increased. If you fit a larger diameter oil pipe the pressure inside it will increase and the velocity in it will fall.
 
all turbos pass some oil is it a lot,presumably youve removed the breather to isolate it as a casuse
Yes, it's a lot of oil James. I have removed the breather and played the end in to a 2ltr milk carton. Nothing comes out. I've also rigged a nitrile glove on to the oil filler cap and there's no blow by apparent what so ever.
I ran the Landy with the new CHRA in the other day for about 8 miles. Then I took the turbo outlet pipe off and took it for a whirl - just under 6 miles.
This is the oil that sprayed on to the outlet pipe that was in the way.
oil.jpg


The kitchen paper I had taped on the wing behind was also covered in that time.
oil on paper.jpg


On a previous investigation I had a look down the oil return pipe union to the block and it looked clear to me
IMG_6393.JPG

Clutching at another straw I think I should take the sump off and look at it from the other direction. When I took the head off and went in through the bottom to take the pistons out to check the honing I'm pretty sure I looked through the return hole then, but I'll have to do it again I think.

Have you seen the britannica you tube video where he is searching for a reason he has oil in the pipework?


Cheers

Cheers, neilly. Yes, I've already watched that video and, as you can see from my reply to JM, I've tested the cyclone breather output with a catch can set up.

Is is coming from the tappets via the cyclone?
Cheers, gymmaniac. Appreciate the suggestion, but see above.
 
How much oil is in the sump? not what it says on the dipstick but actual quantity, remember quoted figures are for a dry fill.
Where are the cartridges you are using coming from?
Have you got a pic of your engine bay?
 
If you are on your 3rd Turbocharger in 2 years, I think the problem is fairly clear.
You need to get a better Turbocharger, or at least get a proper recon job on the one you have.
I don't know where I'm going wrong TM. When I rebuilt the engine I put a shiny reconditioned turbo on it. Started burning oil straight away and I blamed to turbo. To their credit the recon company replaced it. Same thing happened with the replacement. Next I bought a brand new Garrett turbo from Turner engineering and that immediately went the same way. This week I put a brand new CHRA in the new Garrett turbo housing and I'm no further forward. So really, that's three whole turbos and then a CHRA swap. Four turbos effectively. I'm not beaten yet, but I'm ashamed to say my mind is entertaining the idea of giving up :rolleyes:
 
I don't know where I'm going wrong TM. When I rebuilt the engine I put a shiny reconditioned turbo on it. Started burning oil straight away and I blamed to turbo. To their credit the recon company replaced it. Same thing happened with the replacement. Next I bought a brand new Garrett turbo from Turner engineering and that immediately went the same way. This week I put a brand new CHRA in the new Garrett turbo housing and I'm no further forward. So really, that's three whole turbos and then a CHRA swap. Four turbos effectively. I'm not beaten yet, but I'm ashamed to say my mind is entertaining the idea of giving up :rolleyes:
I always use Turbo Technics. Never had any problem.
Not only do they recondition the Turbos, they also make the balancing machines for the cartridges.
 
Yes, it's a lot of oil James. I have removed the breather and played the end in to a 2ltr milk carton. Nothing comes out. I've also rigged a nitrile glove on to the oil filler cap and there's no blow by apparent what so ever.
I ran the Landy with the new CHRA in the other day for about 8 miles. Then I took the turbo outlet pipe off and took it for a whirl - just under 6 miles.
This is the oil that sprayed on to the outlet pipe that was in the way.
View attachment 231411

The kitchen paper I had taped on the wing behind was also covered in that time.
View attachment 231412

On a previous investigation I had a look down the oil return pipe union to the block and it looked clear to me
View attachment 231414
Clutching at another straw I think I should take the sump off and look at it from the other direction. When I took the head off and went in through the bottom to take the pistons out to check the honing I'm pretty sure I looked through the return hole then, but I'll have to do it again I think.


Cheers, neilly. Yes, I've already watched that video and, as you can see from my reply to JM, I've tested the cyclone breather output with a catch can set up.


Cheers, gymmaniac. Appreciate the suggestion, but see above.
thats definitely a turbo issue,
whats your oil pressure
 
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I don't know where I'm going wrong TM. When I rebuilt the engine I put a shiny reconditioned turbo on it. Started burning oil straight away and I blamed to turbo. To their credit the recon company replaced it. Same thing happened with the replacement. Next I bought a brand new Garrett turbo from Turner engineering and that immediately went the same way. This week I put a brand new CHRA in the new Garrett turbo housing and I'm no further forward. So really, that's three whole turbos and then a CHRA swap. Four turbos effectively. I'm not beaten yet, but I'm ashamed to say my mind is entertaining the idea of giving up :rolleyes:

Okay in that case its manifolds off and see if any cylinders are passing engine oil? ie the turbo/s may be fine and you have an engine issue.
 
How much oil is in the sump? not what it says on the dipstick but actual quantity, remember quoted figures are for a dry fill.
Where are the cartridges you are using coming from?
Have you got a pic of your engine bay?
It's a great thought, but I don't think I'm over filling it and blocking the oil return hole. When I change the oil it fill a 5ltr oil container. Then there's whatever is in the filter. I've had the Landy for 16+ years and before the engine rebuild there wasn't an issue with the oil level causing problems.

To be honest the last service kits I bought were from Paddocks, so Britpart stuff.

Do you want a picture of the engine bay wing to wing?
 
It's a great thought, but I don't think I'm over filling it and blocking the oil return hole. When I change the oil it fill a 5ltr oil container. Then there's whatever is in the filter. I've had the Landy for 16+ years and before the engine rebuild there wasn't an issue with the oil level causing problems.

To be honest the last service kits I bought were from Paddocks, so Britpart stuff.

Do you want a picture of the engine bay wing to wing?


i was just thinking pic of full engine bay, and someone may see/say aha I see what you have wrong, you never know we have all done daft things, and had them pointed out to us!

Did you see my post above about popping the manifolds off?
 
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