Crankcase Breather and PCV

CMF_Gareth594 · Dec 10, 2013

Hi All,

I've just joined Micrafiles and I hope someone can help me...

I've recently purchased a modified K11 1.0L (coil pack) car which has been heavily modified. The engine was burning a huge amount of oil under any acceleration and because of the engine modifications I couldn't work out why.

I've changed the piston rings and valve stem seals and very carefully rebuilt but it is still burning oil.

I notice oil on the inlet ports so we think it must be something to do with the breather system/PVC taking oil into the engine. As the car has been modified I don't know the breather system in the car other than the PVC valve at the back of the camshaft cover (looking from the front into the engine bay) and the two pipes going into the Camshaft cover on the left.

Does this sound familiar to anyone? Has anyone seen oil come up into the inlets and enter via the inlet ports?

Any help would be appreciated.

Thank you

G

CMF_frank2 · Dec 10, 2013

the pcv should be on the offside rear of the cam cover gareth (near the brake cyl) any others are just vents

CMF_woohoomobile · Dec 10, 2013

All of the vents on my car were blocked when i got it. it took a bit of effort with a stiff cable tie and parts washer to clear the solid burnt oil from these points.

M y car was not burning oil but was leaking it Every where.

On older engines ive always thought that burning oil, but knowing the bottom end is ok, the cause being valve stem seals.

CMF_Gareth594 · Dec 10, 2013

Thanks Guys

I'll take another look later and try and work it out.

But from what you are saying, the cam cover has three pipes coming out which two are vents (one on the long length of the cam cover facing the rear of the engine bay/induction and the and the other on the right side of the engine closest to the front of the car) leaving the PCV valve being the one of the right hand side nearer the back of the car?

Sorry to be so specific but I'm totally lost and cannot find any diagram/flow that shows the information.

Is the attached diagram correct?

Thanks

CMF_frank2 · Dec 10, 2013

this is the 1 way pcv gareth (that goes to the manifold, and is subject to vacuum conditions), the other 2 are vents

CMF_Gareth594 · Dec 10, 2013

Thanks Frank,

have you ever heard of large quantities of oil going through the PVC value into the manifold?

My car seems to consume a 1:1 petrol / oil ratio which is great for an Aston Martin DB5 in James Bond but not out the back of a Micra...

CMF_frank2 · Dec 10, 2013

Gareth594 WROTE:

"Thanks Frank,

have you ever heard of large quantities of oil going through the PVC value into the manifold?

My car seems to consume a 1:1 petrol / oil ratio which is great for an Aston Martin DB5 in James Bond but not out the back of a Micra...

only when the crankcase pressure was very high mate, have you tried a compression test ? and what c/r does it have ?

CMF_asdamepop · Dec 11, 2013

this is the inside plumbing of the engine cover
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-67#post-537731

and I wrote a rough metaphorical description of how the pcv system flows here
http://micra.org.uk/threads/my-little-knitting-needles-sw7672-1-3-turbo.52965/page-30#post-622193

CMF_hotfunk67 · Dec 11, 2013

Gareth594 WROTE:

My car seems to consume a 1:1 petrol / oil ratio

2 stroke micra, cool

CMF_Gareth594 · Dec 11, 2013

Hi All, I think I have enough information, I'll take the cover off this afternoon and try and see what is going on.

Thank you for your help and guidance!

Gareth

Crankcase Breather and PCV

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