Blue smoke on start up

[JerryETX]

So I have a 2016 6.4 Hemi in my 2500 4x4. I'm the 2nd owner motor currently has 51K (bought it with 36K). I've noticed a couple of times on cold start up a pretty large puff of blue smoke come from the exhaust on cold start up. This is not something that happens often. I've had the truck since last September and can only think of about 4 times this has happened in 10 months and about 15K miles. Doesn't use noticeable oil between oil changes. Might use 1/2 a quart in 3500-4000 miles. I know enough about motors that blue smoke means there's oil leaking somewhere just don't know how concerned I should be.

My question is what level of concern should I have at this point?

 

[SouthTexan]

When was the last time you changed out your PCV valve? Check to make sure it isn't clogged or just change it since they are cheap.

 

[JerryETX]

When was the last time you changed out your PCV valve? Check to make sure it isn't clogged or just change it since they are cheap.

I have not it's not due in terms of mileage but maybe it's past it's age.

 

[czervika]

I get the same on cold start after a short prior drive/start. I.E. move the truck from in front of the house to the driveway. Next morning I get a puff. It's oil sitting in the heads leaking past the guides since the engine didn't have time to warm up on the previous run.

 

[buckeyexx]

Mine will do it if I’m sitting on an incline with nose up. Like said before it’s usually when it’s been started and shut down quickly it will blow a puff of smoke out. I will also get a lot of knock when I dont let the oil pump up and run long enough.

 

[JerryETX]

I get the same on cold start after a short prior drive/start. I.E. move the truck from in front of the house to the driveway. Next morning I get a puff. It's oil sitting in the heads leaking past the guides since the engine didn't have time to warm up on the previous run.

That makes sense. Yesterday the street crew had to patch the road in front of my driveway so I had to move my truck from the driveway out to the street (only ran maybe 30 seconds and was cold when I started it). About 30 minutes later I went to the store and when I started it that's when I seen the smoke.
Thanks for the explanation.

 

[2003F350]

Pretty much exactly what everybody above has said. I've had this on EVERY gas vehicle I've ever owned - if you start it and turn it off right away, then let it sit for a while before starting it again, you'll get a puff of blue for up to 30 seconds (usually much less than that). It's actually pretty normal. If it starts to do it consistently, and regardless of how long it ran before, then you're looking at valve seals needing to be replaced. But I don't think you're at that point yet.