I think I have figured out watch is causing the blue smoke on start up for both 6.4 & 5.7 hemi's

[Lee Stroud]

Hello guys!
I have been paying attention to the times when this happens. If you let one of these trucks sit in the same spot and don't drive it but just start it and let it run then shut it off and restart it. It will produce the blue smoke.
If you drive the vehicle and from work to home and get out and park it. The next morning no blue smoke! But if you start the truck (that has sat in the same spot and not been moved for 2 or three times it will produce this blue smoke!) Think about it if it was the valve stem seals it would do it all time no matter what!
I think that this is the result of the PVC valve on these vehicles! If you have ever watched them take them off the intake. You can see oil running out of the intake runners on these trucks! Not all intake runners but the ones around where the PVC line goes into the intake! Now when you drive your truck it keeps that oil sucked out of the intake and burns it while you drive! It is not enough that you would notice while driving. So you don't see it. Don't forget while your motor is warming up in the morning it is producing water vapor and oil both so this would make it easier for the oil to run into the head and be burnt up! I can't help if they say they have fixed the problem of oil soaking the intake. This is not true!
Now all this I have said above is true unless you have a problem with rings causing excessive oil consumption or valve stems seals causing excessive oil consumption!
I'm talking about an engine that don't use a lot of oil! I have done a lot of studying about this!
These trucks do this when left sitting in the same spot because the oil accumulates in the intake manifold and runs down into the head and this makes it smoke! If you drive it all the oil is sucked out and it will not do this!

The Ram 6.4 hemi needs a catch can for sure!

 

[olyelr]

Or... just let it have a puff of blue smoke occasionally. Does it hurt it at all?


I have noticed this with mine over the years. Seems mine has only done it like you say... if I start it and then fairly quickly shut it back off, next start up could sing the blues for a second. But just a very brief second.

 

[crazykid1994]

Oil residue in the intake and runners can cause buildup which runs the chance of reducing efficiency and performance. I run a catch can to reduce the residue buildup. Yes some vehicles go a long time without them and most people won’t know the difference but if you disassemble and exam the engines side by side the engine with a catch can will be cleaner internally.

 

[Lee Stroud]

Do they make oil catch cans for the 6.4 Ram hemi's ? This has to be the problem instead of valve stems seals because if you park the truck and don't start it until the next morning it won't smoke but if you start it and don't drive it and let it idle then shut it off. Then the next day you start it up it will puff some blue smoke!

Valve stems seals would do it everytime you start the vehicle! Rings would do it all the time you are driving!

If you know of an oil catch can for the 6.4 hemi truck engine let me know!

 

[ScLeCo]

You don't need anything built specifically for a 6.4
It's just a can with a couple of hoses connected to it.
Just get a universal kit and hook it up.
I have a mighty mouse universal kit, works great.

 

[Lee Stroud]

Did it help you with the blue smoke on startup!

 

[2003F350]

Guys...This isn't an issue with just the Hemis. Every gas motor I've ever owned with a PCV has done this. It is, quite literally, because of emissions.

PCV is Positive Crankcase Ventilation. You are literally allowing air from the inside of the engine move into the intake. Hot air contains moisture. A little bit of hot internal engine air will invariably contain molecules of oil.

This oil generally doesn't settle out/build up if the vehicle is being driven regularly and you're using a quality oil. However, if the vehicle sits for days at a time or you're using crappy oil, you will see build up and smoke regularly.

 

[Grand Mesa]

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[Lee Stroud]

I was up until Sept 6, 2019, a Chevy guy! The last Chevy owned was a 2014 GMC 1500 SLT with 6.2 engine. I used two quarts of oil in 6,000 miles. The one before it a 2013 used more. I just got tired of the engine issues. I like the looks of the new Rams so the first Ram I have ever in my life owned is a 2018 Ram Power Wagon with the 6.4 engine. It has 1,467 miles on it. Who knows maybe when the engine gets fully broken in. It might stop puffing a little puff of blue smoke every now and then!

But it is so discouraging when you pay for a new vehicle to have this happen! I call it poor craftmanship and lack of ability to adhere to strict quality control. Engines must be built with total tolerances in machining and parts fabrication. It must be on the money to get a quality engine!

 

[Grand Mesa]

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[2003F350]

I was up until Sept 6, 2019, a Chevy guy! The last Chevy owned was a 2014 GMC 1500 SLT with 6.2 engine. I used two quarts of oil in 6,000 miles. The one before it a 2013 used more. I just got tired of the engine issues. I like the looks of the new Rams so the first Ram I have ever in my life owned is a 2018 Ram Power Wagon with the 6.4 engine. It has 1,467 miles on it. Who knows maybe when the engine gets fully broken in. It might stop puffing a little puff of blue smoke every now and then!

But it is so discouraging when you pay for a new vehicle to have this happen! I call it poor craftmanship and lack of ability to adhere to strict quality control. Engines must be built with total tolerances in machining and parts fabrication. It must be on the money to get a quality engine!

Mine has 37,000 on it (a '17). It still puffs a little blue if I let it sit a few days.

Like I said, EVERY gas motor with a PCV valve does this. It is normal. And if you're driving it enough for the motor to get hot and burn off the oil that does get into the intake, it's not really all that harmful, either.

You also have to remember that these kinds of things are mass-produced. They churn out probably around 100 engines every hour the line is running, per line (I don't know how many they have). It is possible to hand-build an engine that won't burn oil, but you aren't going to do it on a mass-produced engine.

That said, I have never burnt more than about half a quart of oil per oil change in any vehicle I've ever owned, with the exception of the Dodge Omni I used to have that I just gave no ***** about...That thing would burn 2 quarts in a thousand miles.

 

[Leonard Russo]

My 6.4 has 10K on it and uses zero oil between 5 k mile oil change intervals . Never seen any blue smoke yet?

 

[Dusty]

Blame GM for inventing the PCV valve.

The Positive Crankcase Ventilation system for automobiles was invented by Chrysler for California cars in the late '50s. It was called the Cleaner Air Package.

Before that, crankcase vapors were emitted directly to the atmosphere by a tube at the rear of the motor.

Best regards,
Dusty
2019 Ram DT 1500 Silver Billet Laramie, Quad Cab, 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, 18 inch wheels. Build date: 17 April 2018. Now at 024967 miles.

 

[Grand Mesa]

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[JS4024]

Never have I seen any blue smoke from any of my mopar 5.7’s or 6.4’s. And I don’t burn a drop of oil during the change interval. Must be something wrong with mine.

 

[Grand Mesa]

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[Dusty]

Never have I seen any blue smoke from any of my mopar 5.7’s or 6.4’s. And I don’t burn a drop of oil during the change interval. Must be something wrong with mine.

Neither have I. All of my oil gulpers were either GM or Fords.

Best regards,
Dusty
2019 Ram DT 1500 Silver Billet Laramie, Quad Cab, 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, 18 inch wheels. Build date: 17 April 2018. Now at 025008 miles.

 

[olyelr]

My 6.4 has 10K on it and uses zero oil between 5 k mile oil change intervals . Never seen any blue smoke yet?

Never have I seen any blue smoke from any of my mopar 5.7’s or 6.4’s. And I don’t burn a drop of oil during the change interval. Must be something wrong with mine.

I change my oil once a year, right around 10k miles. It has never been low either. But, if you start the truck cold and shut it right back off and let it sit a while, next startup will have a small puff of smoke. Have to be paying attention closely though or you wont even notice it. Its not like some huge cloud of smoke comes out and fogs the area out.

 

[Lee Stroud]

Thanks guys for all your replies keep em coming! I still have not got 2,000 miles on my truck yet! I'm at 1661 miles. I'll see how it goes! I will wait until I get at least 2,000 miles on it before I say anything! It seems to be maybe doing better!

 

[2003F350]

I change my oil once a year, right around 10k miles. It has never been low either. But, if you start the truck cold and shut it right back off and let it sit a while, next startup will have a small puff of smoke. Have to be paying attention closely though or you wont even notice it. Its not like some huge cloud of smoke comes out and fogs the area out.

That's pretty much it. The only reason I noticed that mine puffs once in a while is because my wife was the one starting it and moving it while I did something else...It was a small puff, maybe only 2 cylinders worth. Not even close to enough to notice on the dipstick over a 5k oil change period.

I'm not suggesting that mine burns a ton of oil - it doesn't even register. And aside from one vehicle, any of my gas-motored vehicles that 'puffed' a little now and then were never low at oil change time. What I am saying is that any gasser that sits for extended periods is going to have a small puff if everything is functioning properly, and that if you're not watching, you may not even see it.