Oil shooting out dipstick when driving over 50mph

[Hugomartin]

my 350 has been timed n tuned by a mechanic , new radiator cap but still losing oil pushing out of the dipstick 100 percent sure of this i know its weird i heard it could be the oil separator and flame trap , where are those things located? Thanks

 

[JoeR Jr]

Either your PCV system is totally plugged or you have so much blowby that the PCV system can't keep up. Check your PCV system and then run a compression check. If you're pushing oil up the dipstick tube, you're going to find you answer with those 2 checks.
Joe

 

[Hugomartin]

I checked the pcv valve , it rattles im assuming its good. What else can i check on the pcv 'system' thanks! I havent done a compression test yet

 

[Big Chip]

Make sure you have vacuum at the pcv valve and that the passenger side isn't plugged.

 

[skysurfer]

I started having oil coming out of the dipstick at high rpm after I replaced the hose connecting the valve cover to air cleaner with a breather cap. Don’t know why it caused a problem, breather cap on one side and pcv on the other, but it turned my dipstick tube into a miniature version of Old Faithful. Went back to the stock configuration and everything was fine.

 

[Blmpkn]

I checked the pcv valve , it rattles im assuming its good. What else can i check on the pcv 'system' thanks! I havent done a compression test yet

A leak-down test is what you'd want to do ideally.

 

[JoeR Jr]

I checked the pcv valve , it rattles im assuming its good. What else can i check on the pcv 'system' thanks! I havent done a compression test yet

With the engine running, take the oil cap off. Does it pump a lot of air out of the hole? If you're not sure how much should be coming out if there, compare it to another vehicle. That will give you a rough idea, but it should be a very low volume, and under no pressure at all.


Where are you in NC? Any chance you're near Stokesdale/Greensboro?

 

[fast 99]

Some small blocks also have a lower dipstick tube in the block. Not sure if that has anything to do with your problem but GM put it in for a reason.

 

[Hugomartin]

With the engine running, take the oil cap off. Does it pump a lot of air out of the hole? If you're not sure how much should be coming out if there, compare it to another vehicle. That will give you a rough idea, but it should be a very low volume, and under no pressure at all.


Where are you in NC? Any chance you're near Stokesdale/Greensboro?

Im in durham nc ill check the oil cap for air. I could probbly use an oil catch can ive Never used one im duMping 2 quarts of oil per week

 

[Hugomartin]

Not much air pushing with gas cap off. I decided to remove my dipsting and put a pcv hose with clamp in its place. So far no leaks!!!

 

[RecklessWOT]

Not much air pushing with gas cap off. I decided to remove my dipsting and put a pcv hose with clamp in its place. So far no leaks!!!

I would hope air isn't coming out of your fuel tank.

Otherwise, hey whatever works I guess. That definitely doesn't solve the problem, if 2qts of oil per week are blowing out the dipstick, I guess your little "fix" is better than losing it onto the ground and instead keeping in the engine, but you clearly have a big problem. By any chance do you have a metric sh!t-ton of blow by? Do a compression test, losing oil sounds like the least of your problems

 

[Radiohead]

Would plugged pcv do this?

 

[JoeR Jr]

Not much air pushing with gas cap off. I decided to remove my dipsting and put a pcv hose with clamp in its place. So far no leaks!!!

I'm sure you meant oil cap, nit the gas cap. If not much oil is pushing out, then that lends itself to the diagnosis of a plugged PCV. Losing 2 quarts of oil though points to bigger problems. If you get tired of guessing at it, stop over and we can diagnose it. I'm kjust north of Greensboro.
Joe

 

[JoeR Jr]

Would plugged pcv do this?

When the engine runs, combustion gasses get by the piston rings. It has to escape somewhere or it would pressurize the crankcase, like out the dipstick tube. When those gasses got pumped up the tube, it would take plenty of oil with it, and if the dipstick ends below the oil line, then it would pump a lot of oil out the tube.
Joe

 

[Rusty Nail]

I think dude said it

Not much air pushing with gas cap off.

So far no leaks!!!

Simple enough...?

Replace gas cap, seems it's venting out the dipstick.

Over 50 your fuel return is really flowin!
Take the cap OFF and see how fast you can go without barfing oil, then go buy another one if you don't believe me.

Did ya buy a replacement gas cap and get the wrong one?

Whatcha reckon the chances are of your truck hiding a modification to said fuel return? Pretty good I bet.
Wrong / bad fuel pump?


Ready?

GO!