oil blowing out dipstick
 

Allright fellas please help a brother out ran boat today up to half throttle fine kick it in the but and dipstick blows out and oil everywhere???????????????????????!!!!!!!!!!!!!!!!! !

540ci with 1071 bds blowers

I'd do a compression test, or leakdown test... to find out which cylinder has the hole in the piston.

Like stated above do a compression test at the very least and if that doesn't show anything then do a leakdown test.

MAN THAT WASNT WHAT I WAS WANTING TO HEAR. Ive been reading and ive found alot of comments about ventilators stopped up? I put dipstick back in and crancked motor back up oil pressure holds good! I ran it back to dock bout 1/3 throttle power seems fine

Somehow compression is leaking into the crankcase when you are on it. Some is normal, but if this just started happening then what they said is correct, you need a compression test done to find out if you have a really weak hole, that will be your bad piston.

also have seen where people have said that high hp motors with blowers often require a latching mech. of some sort to hold dipstick in

Blower motors will push the dipstick out under big boost, but normally it does it from the start. Did this just start to happen or has it always done it?

it happened last time i went out to but thought it was a fluke just from checking oil thought didnt put dipstick all the way in. It only comes out about 2 inches. only reason i didnt think it was engine prob is no unusual sounds, good power, temps and pressures good!

If you have decent compression numbers then you can add a spring to the end of the dipstick. Use a small hoseclamp to hold the spring in place and then bend the end to wrap around the dipstick. There are also locking dipsticks for a cleaner look.

Make sure your exhaust is not going bad,I had a riser start going and this happened must have been getting some water in the cylinders and lowered compression.Fixed exhaust and it never did it again.

Make sure not overfull of oil

Yep, check your oil levels. Are your breathers clogged up?

+2

Breathers could be clogged

Like most have already said, it could be a couple different causes, or a combination.
Check leadowns.
Overfull of oil can create excessive windage, which can create crankcase pressure and pop out a dipstick.
Your breathers could be clogged, but this woudl more be a symptom of excessive blowby or windage clogging them with oil. Check them anyway.

My engine, 598ci N/A, would pop the dipstick out at 6000rpm, but would not blow a drop of oil out of any of the valve cover breathers. leakdowns at 4% or so. Put a locking dipstick on it and problem solved.

Lokar makes a very nice billet locking dipstick, reasonably priced as well.

if you do not have a lot of leakdown, you need to get the engine to breathe better..had the same issue on mine with procharger, changed to 5/8 hoses off both valve cover to blower intake cured mine totally...

What do you have for breathers on the valve covers? There may not be enough crankcase ventilation.
Eddie

I thought breather in valve cover were there to exhaust pressure from crankcase, not to breath from those valv cover hoses... was I wrong?

They both do the same thing, relieve pressure from the crankcase. Sometimes those hoses to the flame arrester just aren't enough. Especially if you increase your cu.in.'s.

on prochargers, they run right off the fittings on the valve covers to the the air bell on the supercharger, when mine were 3/8 blew oil out of dipstick...changed the fitting and hosed to 5/8 cured instantly...that pressure has to go somewhere..better blowing the dipstick than the intake end gaskets..which will as well....

if it is running without a dead hole, your rings might just be stuck, been there done that, blower motors that spend too much time idling build up a thick carbon like film around the ringlands and then the rings dont seal properly... this is my opinion as you dont seem to have a problem in the lower rpm range... a hole is a hole no matter what rpm ur turning... trust me you'd know if she were dead!!

this of coarse is assuming that breathers are of correct size. I run -8 out of both v/c and a pcv valve in the valley just ahead of the dist... pcv plumbed to breather, valve covers vent to puke tank on my 900scs (10:71 blowers)