Brown oil coming out of valve cover breather

"So the motor was beleived to

"So the motor was beleived to have a cracked head
i started it up let it idle for a bit, sounded great revved it up to about 4500 for a few and then the brown started pouring out of the breather. I looked in both valve covers and its brown froth.The oil reads really high on the dipstick not brown though.Iam thinking this couldnt be all from a cracked head.Cracked block new motor?Let me know what you think.
Adam"

"Hi,

In my opinion, the oil

"Hi,

In my opinion, the oil may not have a funny colour in the dipstick because normally the dipstick tube goes to the bottom of the pan so that you can pump out the oil through it. Therefore, what you see could be very much a sample of the oil you initially put in. However, when the oil level goes up with you adding any oil, it can be either due to water or (rarely) fuel ingress in the crankcase. Since water is normally the problem, possible sources could be a cracked head or a defective head gasket. A defective intake manifold gasket could aslo do this in many engines.

To find out whether or not you have water in the oil, a simple an inexpensive way is to perform a crackle test. You can search in Google if you don't know how to do it."

"I guess it would depend on wh

"I guess it would depend on where the crack in the head was. If the crack is in an area where the water can pass into the oil jacket then run down into the pan then yes it could be the head.
But the head on a V style engine doesn't crack in this way very often. In fact,now that I think about it I've never seen one do this.
The water jacket in the block is much thinner & will break / crack sooner the the head will.
This is more so if freezing is thought to be the cause of the crack.

There could be as stated before a bad head gasket. This may or may not show up with a compression test. It depends on how close to the cylinder & how bad the gasket is.
The head or intake gasket could be leaking from the water jacket to an oil port. In this case the compression would not show any change from one cylinder to the next if it was the head gasket but water would leak into the oil system.

If it was the intake gasket the water would run in under the intake to the lifter gallery then drain to the pan.

You didn't give the age or model of the engine but if it's an older model I'd check the intake & then the head gaskets for signs of leaking if the engine having been frozen is not a concern.

If you think this may have frozen then once the intake is removed you can inspect the lifter gallery for cracks in the water jacket.

The walls of the water jacket under the intake just above the lifters are the weak point in the water jacket on V style engines & most times break before anything else does if the engine was frozen.

If this engine has had this leak for awhile there will be rust in the area of the leak making it easy to spot once you do get to it if it is a crack.

If this is a GM V8 I'd go with the block being cracked before the heads.
I've seen some of the GM engines split on the inside & outside from one end of the block to the other from freezing & the heads were still good. The heads do not have much of a water jacket & the water is not above the intake up in the head when the engine is not running giving ice room to expand before breaking the head. Plus the head is very thick.
I'm not saying these heads do not break just that it takes a lot to hurt one compared to the block.

It sounds like the removal of the intake & heads is the only way to know foresure.

There is only 5 ways for water to enter the oil system. Cracked block, cracked head, leaking intake gasket, cracked intake water jacket above lifter gallery or a bad head gasket.

If an exhaust manifold was leaking the water would have to pass the piston to enter the oil system & foresure the engine would hydro lock at sometime if this were the case.
Plus it would run like crap & think of how bad the rings would need to be to allow any amount of water to pass.

Just my opinion on the subject from what you said you have. Best of luck."

"I'd put my money on a cra

"I'd put my money on a cracked block, sorry."

Thanks for the replys.
It is

Thanks for the replys.
It is a 1997 4.3 v6.I bought the boat figuring on a new motor hoping for just a head.The previous owner thought the head cracked because of freezing.So odds are new motor. Oh well at least with a new motor I know how many hours it has and how it was taken care of.
It still amazes me how much brown foam was shooting out of the breather tubes and the motor wasnt missing a beat.crazy
Thanks again
Adam