Turbo Diesel Crankcase air

[gstsaver]

2013 Mini Countryman N47 1.6 R60 **AIR IN CRANKCASE ISSUES***

Fixed timing chain. Engine back in.

When I remove oil filter cap lots of air. NO smoke there or at exhaust.

Put oil cap on and massive oil leaks from rear seal. Leave cap off and no leaks at all.
No smoke, no loss of power ....so doubt it is piston rings.

What can this possibly be - The ccv seems to be working as even though lots of air out oil filler hole , when I go to put it back on there is suction (obviously so much so it must cause oil leaks.

What can possibly cause air to be coming out that is like blowby but no vapors or oil etc....just air...no smoke no smell...? Can it be some turbo leak issue ?

Btw I have a decent scanner and NO CODES.

[GreenV8S]

When the CCV system is in place, do you get positive or negative pressure in the crank case?

If it's positive, you have either excessive blow-by, or a blocked CCV system. If it's negative, you might have a blocked crank case vent.

[stevieturbo]

gstsaver said:

2013 Mini Countryman N47 1.6 R60 **AIR IN CRANKCASE ISSUES***

Fixed timing chain. Engine back in.

When I remove oil filter cap lots of air. NO smoke there or at exhaust.

Put oil cap on and massive oil leaks from rear seal. Leave cap off and no leaks at all.
No smoke, no loss of power ....so doubt it is piston rings.

What can this possibly be - The ccv seems to be working as even though lots of air out oil filler hole , when I go to put it back on there is suction (obviously so much so it must cause oil leaks.

What can possibly cause air to be coming out that is like blowby but no vapors or oil etc....just air...no smoke no smell...? Can it be some turbo leak issue ?

Btw I have a decent scanner and NO CODES.

So how could suction, ie. negative pressure in the crankcase, cause it to push oil out of the crankcase ?

With a working PCV/CCV system, there should be air drawn through the crankcase, and some degree of negative pressure/fresh air always drawing through it.

Now if you've done something to screw up CCV operation and there is positive pressure in the crankcase, that could help contribute to leaks...and it's easy to rig up some sort of pressure gauge to see.

[gstsaver]

I made a homemade compression tester, put on tdc and using adapter went in through glow plug and it does NOT hold air at all.
Not coming out the exhaust or intake so must be passing by pistion.

However, there is no smoke out exhaust when driving...none at all.

It also hasn't lost any power.


This makes no sense at all. If there was smoke I could see that perhaps the air was leaking past the pistons ..but no smoke at all..just blow by. How can this be ?

[shogun001]

You've put that you pulled the engine in order to fix the timing chain, had it snapped or jumped a tooth or did you get to it early enough?

[GreenV8S]

gstsaver said:

I made a homemade compression tester, put on tdc and using adapter went in through glow plug and it does NOT hold air at all.

Not coming out the exhaust or intake so must be passing by pistion.

Probably best make sure you understand how to do a test before you do it, otherwise you risk coming to false conclusions - maybe even damaging things. What you did there isn't a compression test. It was similar to a leakdown test, but not done properly. Pistons are never a perfect seal in the bore - there are standard tests that will determine how much leakage there is and whether that is excessive. I suggest you answer the questions that have already been asked here rather than try to guess at ways to diagnose it.

[gstsaver]

The timing chain had snapped but barely touched the pistons.

Took the head to a machine shop who checked and the valves weren't bent, the grinded them, new seals etc.

As for the leakdown test that is what many others do for a homemade leakdown tester for diesels. Modify a compression tester , put a T in and put air in the cylinder on TDC (about 30psi) and see if it holds air (through compression gauge). It doesn't which is strange as if valves weren't even bent, so low impact and the pistons should be fine.

The real head scratcher is no smoke but lots of air our the crankcase.

[GreenV8S]

gstsaver said:

As for the leakdown test that is what many others do for a homemade leakdown tester for diesels.

I don't know about the 'many others' doing it that way, but that isn't how to do a leakdown test. The test is measuring the leakage rate, not testing whether there is any leakage (there always is).

[gstsaver]

Leaks 100% of air

[GreenV8S]

gstsaver said:

Leaks 100% of air

Obviously. As is perfectly normal.

[gstsaver]

But doesn't hold air for even a split second

[GreenV8S]

gstsaver said:

But doesn't hold air for even a split second

If it runs, obviously it seals to some extent.

If you think there is a ring sealing problem you need to do a leakdown test properly to find out. Just connecting up an air line doesn't tell you anything, especially if you have no idea what is normal..