bad oil separator?

[John V]

If oil is pooling on top of your engine your oil fill tube is leaking. It may be cracked or it may just have a leak in the joint between the upper fill tube and the tube that meets the engine. The oil fill tube is a thin black plastic tube which is about 1.5" in diameter. If you run your finger under the underside of it and it comes back with fresh oil, you know that joint is leaking.

I disassembled mine, cleaned the interface with acetone, then sealed it with RTV since it was not cracked. No leak.

[wanna986]

Originally Posted by John V

If oil is pooling on top of your engine your oil fill tube is leaking. It may be cracked or it may just have a leak in the joint between the upper fill tube and the tube that meets the engine. The oil fill tube is a thin black plastic tube which is about 1.5" in diameter. If you run your finger under the underside of it and it comes back with fresh oil, you know that joint is leaking.

I disassembled mine, cleaned the interface with acetone, then sealed it with RTV since it was not cracked. No leak.

My pooling is safely a few millimetres deep and is contained by the waffle design of the casting.

So the AOS may be o.k. and it's just a leak at the junction? I guess my question is "What's the oil doing way up there?"

I have to try the oil cap as soon as I can.

Thanks, all.

[John V]

Way up where, in the oil fill pipe? Oil vapor is present in that pipe and if the seal isn't perfect, it will drip down. Pretty simple.

[Lil bastard]

In addition to de-foaming the oil, it's also an emissions device to keep the crankcase vapor from venting to atmosphere. Instead, it is drawn into the intake and burned during combustion.

[Zuffen]

Originally Posted by John V

If oil is pooling on top of your engine your oil fill tube is leaking. It may be cracked or it may just have a leak in the joint between the upper fill tube and the tube that meets the engine. The oil fill tube is a thin black plastic tube which is about 1.5" in diameter. If you run your finger under the underside of it and it comes back with fresh oil, you know that joint is leaking.

I disassembled mine, cleaned the interface with acetone, then sealed it with RTV since it was not cracked. No leak.

Hey John V, I think this is exactly what is happening to my 2000 Box. I do not think my AOS is bad (new version and pretty clean all around it) No smoke from the exhaust. I did get the pooling of oil on the passanger side and underneath the join of the fill tube there is oil.

Question: How was the removal and cleaning process? Any guidance on how to do it will help. What is RTV?

Thanks in advance.

-Zuffen

[Lil bastard]

It is a silicone sealant. RTV stands for Room Temperature Vulcanizing. Most general purpose silicone sealants are RTV type. It generally uses an acedic acid based solvent and is characterized by it's vinegary smell.

This form of sealant starts to cure as soon as it is exposed to air/moisture.

There are several types of silicone sealant.

Anaerobic silicone is usually 2 parts which must be mixed together and sets quickly. It does not require exposure to air to cure. It is often used in sealing engine halves, valvecovers, etc. where the silicone is pressed between 2 surfaces and not exposed to air.

UV or Radiation silicone sealant will only cure under exposure to ultraviolet light.

There is also Thermo or Thermoset silicone sealant requires exposure to heat in order to cure.

[wanna986]

There is definitely vacuum present when I remove the cap.

Once the cap is removed, the engine starts to get rough, stumble and "chug". I put the cap back on and things smooth out. What's this say?