Fc420v blowing oil out the dipstick tube

[ras8539]

Engine on a John Deere lawn tractor. Oil was leaking from the dipstick tube. I took out the dipstick while the engine was running and it blew a plume of oil into the air.

Took off the valve cover and inspected the breather Reed valve. The gap is right and the valve flaps when the engine is cranked. With the dipstick out the valve still flaps, but I can feel the push/pull on my hand - I was holding a rag over the tube to keep the oil off the ceiling. I took off the Reed valve and the tube to the crankcase is clear and clean.

The oil level is spot on, and the oil is clean after a couple of mowings and the engine starts right up with no smoke so I'm thinking it's probably not blowby.

I'm completely stumped. Any thoughts?

 

[Scrubcadet10]

Normal.
When running there's a fine mist of oil blowing around the crankcase, and then the ever changing pressure and area of the crankcase changing due to the piston moving. when you take the dipstick tube off, there's an outlet for it.,

 

[Auto Doc's]

You don't remove the dipstick and cap while running. These are not like a car engine.

Inside the crankcase there is oil and air constantly being "slung around" while running . It is known as windage and often referred to as splash lubrication. The moving parts inside the engine rely on this cooling and lubrication of the parts.


The likely initial seeping of oil was from the dipstick tube O-ring. The get brittle with age.

Check out parts tree for your exact engine using the label tag on the engine itself.

PartsTree - Home of OEM Parts for Outdoor Power Equipment

Parts lookup and repair parts diagrams for outdoor equipment like Toro mowers, Cub Cadet tractors, Husqvarna chainsaws, Echo trimmers, Briggs engines, etc.

www.partstree.com

 

[ras8539]

Well, at least I know why I didn't find anything wrong. Thanks guys!

 

[Its Me]

Engine on a John Deere lawn tractor. Oil was leaking from the dipstick tube. I took out the dipstick while the engine was running and it blew a plume of oil into the air.

Took off the valve cover and inspected the breather Reed valve. The gap is right and the valve flaps when the engine is cranked. With the dipstick out the valve still flaps, but I can feel the push/pull on my hand - I was holding a rag over the tube to keep the oil off the ceiling. I took off the Reed valve and the tube to the crankcase is clear and clean.

The oil level is spot on, and the oil is clean after a couple of mowings and the engine starts right up with no smoke so I'm thinking it's probably not blowby.

I'm completely stumped. Any thoughts?

you say you have a leak, a leak from where it goes into the block where the rubber bushing is, threads around the cap on top of the tube, crack in the tube but if you remove the dip stick while it is running you are going to get a shower of oil, you cannot not remove it without out like you say "keep if off the celling" its under pressure, if the cap is screwed down and you have a leak, might have to change the dip stick and the tube.

 

[SeniorCitizen]

Personal experience when i forgot to screw the the stupid dip stick in that by design just sets on the tube to check oil level . In < 5 minutes makes 1 hellofahmess .