Crankcase breather oil leak

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aj81spider
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Crankcase breather oil leak

Post by aj81spider »

When pulling my oil filter mount off (see other thread) I noticed a reasonable amount of oil appears to be leaking from the small hose on the crankcase breather. Any thoughts on why/how this might be happening?

I suppose I'm going to have to pull it off to see what's happening, but could use some insight into what to look for.

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A.J.

1974 Fiat 124 Spider
2006 Corvette
1981 Spider 2000 (sold 2013 - never should have sold that car)
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bradartigue
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Re: Crankcase breather oil leak

Post by bradartigue »

- A cracked hose
- A nasty separator that needs to be removed, cleaned, and replaced
- A bad separator base gasket, and while you're in there, clean the separator and replace the hoses

All of the the above are easy. If you are actually getting some quantity of oil then it is likely oil and radiator fluid, meaning you have blow-by from either bad rings/worn bores or a bad head gasket. Head gaskets aren't hard but the other is a bit of a pain in the ass.
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aj81spider
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Re: Crankcase breather oil leak

Post by aj81spider »

Thanks Brad,

The engine is newly rebuilt, so I'm hoping it's one of the simple ones or my rebuilder did a worse job than I already think he did (although I'm still cranky if he didn't replace the hoses and clean the separator).

I'll pull it off tomorrow and see what it looks like.
A.J.

1974 Fiat 124 Spider
2006 Corvette
1981 Spider 2000 (sold 2013 - never should have sold that car)
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aj81spider
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Re: Crankcase breather oil leak

Post by aj81spider »

So in what I'm guessing is bad news - I pulled everything off. The seperator was clean and unimpeded. The small hose was in fairly good shape. No obvious cracks and the rubber seemed supple.

The big hose was new (I put it in), and it had some oil in the lower (closest to the block) end.

Things were oily, but otherwise pretty clean.

The only obvious abnormality was that there was no gasket on the base of the separator. I have new hoses and a gasket on order - but it looked like the oil was coming out of the base of the small hose, so I'm a little worried that that won't solve the problem.

On the positive side, it appears that the leak I noticed when looking at the exhaust on a lift (see other thread) originated here - so I only have one leak to deal with (that I know of).
A.J.

1974 Fiat 124 Spider
2006 Corvette
1981 Spider 2000 (sold 2013 - never should have sold that car)
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bradartigue
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Re: Crankcase breather oil leak

Post by bradartigue »

aj81spider wrote:So in what I'm guessing is bad news - I pulled everything off. The seperator was clean and unimpeded. The small hose was in fairly good shape. No obvious cracks and the rubber seemed supple.

The big hose was new (I put it in), and it had some oil in the lower (closest to the block) end.

Things were oily, but otherwise pretty clean.

The only obvious abnormality was that there was no gasket on the base of the separator. I have new hoses and a gasket on order - but it looked like the oil was coming out of the base of the small hose, so I'm a little worried that that won't solve the problem.

On the positive side, it appears that the leak I noticed when looking at the exhaust on a lift (see other thread) originated here - so I only have one leak to deal with (that I know of).
If it was a real new engine then I would just clean it up, tighten the hoses, and check in about 1,000 miles.New engines can be leaky and nasty for a little while as things get seated.
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