300 Tdi Oil Leak

[Stefano]

I've got a new oil leak that I can't find. It is definitely engine oil. I suspect the oil cooler but saw nothing when I removed the fan shroud.

What part of the radiator is dedicated as oil cooler? It is a few of the bottom rows or just part of the end cap?.....???

 

[javelinadave]

Hard to tell from the pictures. I would clean it off real good and take it for a short drive. Hopefully the source appear.

 

[expanse]

spray down/clean whole area, run it around the neighborhood a few times, see where it leaks.

R&R the leak'n paht

 

[Stefano]

It's clean as a cat's a**! I spent over two hours under it with a pressure washer just 500 miles ago and haven't driven it off road or in the rain since. The newly oiled surfaces you see in the photos, have developed in the last 100 miles, but I still can't tell where it is coming from. It's so clean that it only drops one or two drops of oil every time I park it simply because oil is still spreading itself over all the clean surfaces.

I've removed the radiator shroud to inspect as much of the radiator as possible without removing it and don't see any oil anywhere on the radiator.

That's why I'm asking what part of the radiator is dedicated as engine oil cooler. If it's the very bottom of the radiator then it might be that and I will pull the radiator and have a look. I just don't want to pull the radiator not having a clue as to which part of it has oil in it because if the oil cooler section stops at the lower oil line then the leak is not in the radiator because I can see all that already.

 

[jymmiejamz]

Is it possible that oil is coming out of the intercooler or intercooler hoses? Looks like your leak is on the left side and the engine oil cooler is on the right side of the radiator.

 

[erover82]

It may be clean, but it’s not dry. Finding an emerging leak without first being degreased is very difficult. I’d degrease until dry and then inspect everything with a light after every drive. The source should then be apparent.

 

[michael67]

The oil cooler sits fully inside of the radiator end cap immersed in coolant and is not part of any of the rows. If the oil cooler was leaking at any place other than the fittings you'd have oil in your coolant. I have had the fittings leak coolant but not oil.

Are you sure it's engine oil and not power steering fluid? Or, a long shot, oil from your fan's viscous coupler?

 

[Stefano]

Thanks for the info @michael67. Saved me pulling the radiator.

And all others, you've convinced me, I suppose I'll re-clean and start seaching after short trips.

Thanks,

Stephan

 

[Siia109]

Looks like its the power steering - The fan might be whipping it around - its tough to tell, but consider all the options (meaning anything that has oil is suspect! LOL).
Wipe it down, start it up and lay underneath it to see whats what... Have someone hold 3000 rpm to increase pressure then when you get some in your mouth you can be a "Guess that Fluid" contestant!

 

[Stefano]

Solved. I re-cleaned and one of the lower IC clamps was a little loose.

Which begs the question: Does the IC need to be removed and de-greased (de-oiled) occasionally to restore it's cooling capacity? The 300Tdi only has 80k miles on it and runs like a top so wouldn't think the cyclonic breather was being overwhelmed.

 

[michael67]

I've had my intercooler out a few times and it's always been clean - no oil or fuel collecting at the bottom; I haven't cleaned it since my head gasket failure, so maybe it's dirty. The service manual says it's required to be cleaned occasionally, and it's not a difficult task to remove. I just run some degreaser through it, followed by lots of water, then compressed air + dry time. I plan to clean mine again later this summer.

 

[Ansley Rover]

Oil can also get in the intercooler from a failing turbo seal. Ask me how I know. To be leaking from the intercooler hose there must be a significant amount of oil in there that shouldn’t be. If it’s the turbo, you need to fix it asap. I’d make sure that’s not your problem.

 

[Stefano]

Sounds like that gets moved to the top of the laundry list.

Since the crankcase breather enters the plumbing before the turbo, how do you figure out where the leak is from?

No detectable oil loss in the 2,500 miles since I’ve owned it.

 

[Ansley Rover]

I’m not familiar with the layout of the 300tdi - I have a 200tdi. I’m sure many on here can tell you how to figure out which one. But if it is the turbo, it can be catastrophic if a lot of oil leaks into the intercooler and then ends up getting pumped into the intake/cylinder. A shop hydrolocked mine that way and bent a connecting rod after it ran away. I was lucky it didn’t crack the water jacket or do worse damage. Had to rebuild the whole thing.

Not trying to scare you, just want to help you prevent a potentially much worse problem. Replacing the turbo (at least on the 200tdi) is easy, though not a cheap part.

 

[hillstrubl]

It may be clean, but it’s not dry. Finding an emerging leak without first being degreased is very difficult. I’d degrease until dry and then inspect everything with a light after every drive. The source should then be apparent.

Maybe put some painters tape on the cleaned parts under the radiator/bumper too to see where its dripping specifically?

 

[erover82]

Tdi's blow too much oil down the separator and the excess gets sent through the intake. This gums up the intercooler and lines. It also contributes to intake hose delamination and then they collapse causing air restriction. One possible fix is to fashion a baffle, like many other engines have, that prevents rocker oil splash being sent directly down the separator. Another is to implement a catch can separator between the factory separator and intake.

You may also want to check for excessive piston blow-by. Loosen the oil cap while it's running and see if the crank case pressure tries to blow it off. Here's an example of too much pressure.