SweetZRag

Last oil change I sent my oil out for testing and they told me there was a very small amount of antifreeze contamination in my oil. I changed it again last night (after another 3,000 miles) and found milky oil (about 4 ounces) in the oil separator I previously installed in line with the PCV valve. The oil in crankcase looked fine. No visible signs of water. My coolant level has never dropped.

During past oil changes, I found a trace of milky substance in the separator and always believed it was condensation and not a problem. There was a lot more last night.

Does anyone have any ideas why I would find water in the separator and not a visible amount in the crankcase? Do I have a leak and where should I look for it. I am trying to avoid ripping the top end apart if there is something else going on.

bw_hunter

I think your first assumption is correct. Since the seperator works the vapor coming out of the crankcase, you are most likely seeing condensation and nothing more.

You probably have more than you did before simply because it's getting cooler out.

SweetZRag

I live in NJ so it has gotten noticably cooler since the last oil change. I hope you are right. If I understand the process, the air pressure in the crankcase is vented through the PCV valve and into the air plenum where it is burned off in the combustion chamber.

How else would outside air get into the crankcase besides blowby from the cylinders? Does air flow into the passenger side valve cover from the throttle body through that vent line? I am just trying to understand how the moist outside air could be introduced into the system.

When the testing lab told me there was a very small antifreeze contamination, I assumed I might have some seepage from the head gasket. I have not retorqued it since the rebuild about 70K miles ago. I am planning to do that.

If the separator picked up that much condensation, this device is doing a great job.

bw_hunter

Fresh air is supplied via that the tube that plugs into the passenger side valve cover. The outside air isn't necessarily moist...water is a byproduct of combustion. These combustion products have two paths to the crankcase...getting past the rings as blowby is one and the EGR is the other. It's quite normal to have some of this material present. Your seperator might actually make the volume seem worse than it really is as it seperates the liquid from the vapor immediately on startup..once the engine warms this phenomonon is minimized.

When the oil analysis folks mentioned anti-freeze in the oil, did they mean that or could they have meant water? You should ask...there isn't any good way for antifreeze to get in the crankcase...only bad ways. I ask because it's itsn't that easy to pick glycols out from oil during an analysis...but water is a piece of cake.

SweetZRag

They detected components of the antifreeze. I need to find the report to remember exactly what chemicals they found but I think it was potassium and one other chemical. I spoke to the guy and he said it definitely was antifreeze. I'll post a link to report once I locate it.

bw_hunter

OK, potassium? That shouldn't be in antifreeze. Maybe aluminum or sodium silicates but Potassium is weird. The basic anti-freeze material is a glycol of some type, usually ethylene, diethylene or propylene, The anti corrosive additives can be all sorts of things. I'll take a look at the link.....

Oh yeah, glycols smell 'sweet' when they burn....without asphyxiating yourself, smell the exhaust. Maybe stick your hand in it and sniff that. Anyway, you should be able to pick up the unique odor. If you have questions you can do it to another car and compare....

SweetZRag

It was potassium and sodium that indicated an antifreeze leak. They said Valvoline uses some sodium as an additive but not as much as was in my oil indicating an antifreeze leak. Here is the the link the entire report:

http://www.yousendit.com/download/dk...YXloMld4dnc9PQ

No smell in the exhaust and the level does not drop so I think any leak would have to be small. I was surprised by the amount of milky oil the separator trapped.