18 replies to this topic

[hepple]

My Mini, over the last month has been throwing out oil from the Crank Case breather. Have check all compression etc .. All perfect. Running excellent Oil Pressure too.

We narrowed it down to breathing too heavy, so I fitted rocker cover with a breather on it. After this it stop putting Oil out of the Crankcase breather, excellent ...

On route to Malvern today (first proper Motorway journey) it started doing it again, it also threw it out of the rocker cover breather.

The only thing I can think of now is that I have a blocked Oil gallery.

My question is:

1. Is there a way to check if I have a blocked Oil gallery?

2. How can a blocked Oil gallery be fixed?

Thanks in advanced

James

[ANON]

rings

[hepple]

I thought that but Compression is 160 through all 4 pistons ....

[Ethel]

It's hard to see it being anything other than blow by. It has nothing to do with oil pressure, that'd be like expecting the air pressure in your shower to increase because you've turned the water on. A compression test is a measure of the engine's ability to cram air into the combustion chamber, your rings could leak nearer the bottom of the piston stroke without effecting the test results. They also have to hold much higher pressure on the power stroke.

[hepple]

So could be Piston rings still :/

Is there any other ways in which I can check the piston rings with out stripping the engine ?

James

[liirge]

are you sure your breather cannisters aren't just full of crud?

try taking them off and bathing them in diesel and blowing through with compressed air, see if that aids the problem.

[Ethel]

Not conclusively, you can't really replicate the conditions in a running engine. A leak down test might tell you a bit more, as might removing the head to inspect the bores - but it might not & you can't see the rings or the bore at the very bottom of the ring travel. You could rig up a pressure gauge to show the crank case pressure on the road. If it runs ok, you could put your efforts into controlling the oil loss with a catch tank. But it sounds like you'll be looking at a rebuild eventually.

[hepple]

Have cleaning the crankcase breather out and the rocker cover had a new k&n type filter on it.

[hepple]

Might try and go and get a leak down test done then.

Too much Oil gets thrown out to control it really. The Crank Case breather does go into a Catch Tank (Water Bottle) and it filled up within around 10 minutes on the Motor Way.

Thanks
James

[racingbob]

i had this on a race engine catch tank filling up with oil just like yours if i can recall it was rings

[hepple]

Sounds like it could be an excuse to build an engine over winter ....

[liirge]

Wow thats a lot of excessive crankcase pressure, the rings must be completely gone. Have you run this car with a loose filter linkage?

I've had this once, an old Perkins AD3.152 engine, made popular by its usage in the Massey Ferguson 135 tractor, anyway, after a days work out on the field, mainly transport work, the sump would drain from full to empty. It was leaking out of every orafice it could find, including the rocker cover breather.

[hepple]

Then you would think that the compression test wouldn't be perfect if they were completely gone.

What do you mean by loose filter linkage?

[liirge]

Air Filter, debris ruining the bores.
depends how bad the rings are, sometimes oil will always be in the cylinder causing a good reading.

[dklawson]

What do you mean by loose filter linkage?

I wondered that also. Perhaps liirge meant "leakage" not linkage?

My take is the same as those above who suggested bad rings. A leak down test will identify all sorts of problems and do a better job of it than a compression test alone.