Hello i am new to this and also new to owning a hemi, my truck is a 2012 ram 1500 tradesman 5.7l hemi, I have read numerous threads about stuff that could be wrong with my truck.. heavy oil consumption is really the only issue other than some times it kinda hesitates to start kind of like it is trying to catch up (I was thinking crankshaft position sensor could be an issue) anyway about the oil I have taken the mass air off and opened the throttle body and it was oily however I have not yet looked down into to notice if any oil is puddled in the bottom but I am thinking my plenum gasket is shot, my question is I have looked for the gasket or even a video of how to replace it and cannot find anything? The truck runs good I travel for work and it has no issues on the road other than oil consumption also a slight blue puff of smoke on startup but after that all day you can start it without smoke but it will idle all day without a miss or sputter needless I am a bit confused lol there are also no leaks on the motor

 

You aren't finding anything on the plenum gasket for your truck, because it doesn't have one. That's an issue on the older magnum engines. (3.9, 5.2, and 5.9)

How many miles on your truck?

Moving this to fourth gen ram section.

 

well that's what I had about decided is that it didn't have one and the truck has 126k miles on it

 

Think I would first take a long, hard look at the PCV system, I don't know if yours has an actual valve, or, if its just a restricted orifice somewhere.

 

It has a PCV valve on top of the motor I was told that if you take it out and it rattles then it's good so I checked mine and it was rattling

 

Time for a compression, or cylinder leakdown test then......

 

ok thanks!

 

Having had the pleasure of thoroughly enjoying and mile-ing out a number of trucks, I can only speculate from a distance what you might have there. I will toss in a few comments which may or may not be helpful.

Oil consumption only comes in two forms. External or Internal.
- External means it is leaking out somewhere. If you crawl under, over, through, within all nooks and crannies of your truck: are you seeing evidence of oil leak anywhere? I am not talking about dried and weathered oil/grease from years/months ago. Look for anything that seems recent, wet, damp, weeping, dripping, ... ongoing. For external leaks, almost in every case (on my trucks) the cause was a PCV and vacuum system that wasn't working properly. This can lead to leaks at crank seals, excessive oil mist carryover into intake, leaking valve covers all because the crankcase pressures up instead of being under a vacuum it is supposed to be. The PCV can be dirty, sticking, or internal spring weak, it may seem ok but it really is very simple to just replace it and be done with that. The next is to check that all of the vacuum and vent lines are clear and not cracked, leaking, or sucking anywhere not supposed to. Over time, it is really quite amazing how much sticky slimy snot can gets hung up in the PCV system and undersides of valve covers to eventually cause operating and oil consumption problems.
- Internal means the oil is being consumed or hung up internally some how. A few possibilities to list off are: worn piston rings and/or valve guides allowing oil into the combustion chamber and burning it off. Another, is again an improperly functioning PCV system which is drawing excess crankcase oil mist into the intake and burning it off. Another is how about poor quality oil or old overrun oil. When was the last oil change? My engines detest old oil (synthetic or not) and poor quality oil. Crappy oil sticks more to parts, gets burned off, it gets hung up in the valve train, galleries, recesses, and sludges. Both show up as a drop in the dipstick level. Burning it off, low dipstick. Hanging up and sludging in the engine, low dipstick.

I might be inclined to suggest trying a couple of really simple things. Start out with a new PCV and inspection/cleaning of the insides of all the vacuum/vent hoses. Then do 2 or 3 short term oil and filter changes with quality high detergent oil. Short, like 500 - 800 miles changes. If it doesn't smarten up from those, then you are into the worn rings and/or valve guides job, sorry.

Going back to my opening statement of having miled out a few trucks... that puff of blue smoke on startup and running fine rest of the day otherwise is deja-due and really indicating tell tale, unfortunately. The good news is it will run fine like that for quite awhile yet, like another 50,000+ without any hiccups as long as you are not hard or too demanding on it. There is also some is hope it can be something else (eg excessively fuel rich startup) and perhaps checking and doing the couple of simple things mentioned will clear the air and/or lead down a different path. It will either get better or stay the same. Whatever you do, do NOT ever put any kind of stop leak or engine fixer upper smearered power sealer slickener stuffner tightener in there! Put in good quality oil at frequent changes, and absolutely never ever anything else. A clean engine is a happy engine, and nothing cleans an engine better than quality oil on a short changeout regimen.

Hope that helps, in some way!

 

thank you sir for your input, what would be a good quality oil? I use Mobil one not really up to par on quality of oils lol I will check vacuum lines and will just replace pcv it's a simple part atleast to start with, I have been under and over on that motor and no leaks anywhere so i was believing it was internal

 

An oil/filter debate can be a long deep hole really fast, LOl! ....

I had been running Mobil for awhile but I quit using it. I was finding that the Mobil was always clean on the dipstick. I really didn't like that. Even towards the end of my oil change intervals the dipstick level would drop, yet the oil still showed remarkably clean. The engine would get a noisy valve train and start burning oil, a prime indicator that it is time to change it, but sampling would show nice fairly clean oil. To me an oil that stays clean/amber isn't doing its very important secondary job of cleaning, disolving, and suspending contaminants. A clean run gives me the impression of like trying to wash the grease off you hands with water and no soap. The water stays nice and clean but your hands are still dirty, no matter how long your rinse or rub. I am not saying to not use Mobil. Just saying that I didn't like it and went to something else. "Others' mileage may vary."

The want is for long life out of the oil and filter, however I also really want to see the oil get progressively dirtier over runtime, that is one of the windows into knowing what is going on in there. To the point, I quit changing oil on odometer mileage a long time ago. I go by how the engine is behaving and the color of the oil. If the engine is getting noisy and ticketty, change oil. If it starts to burn oil excessively, change oil. If all seems good but the oil is getting dark to black, change oil. The result is some oil changes happen at 2000 miles, and others at 6000+ miles. It just depends on the driving conditions and what the engine is telling me.

As for what oil to choose, there is a high risk of this thread going down that hole and turning into a "Hey look!, Another oil thread!". To package wrap the answer to your seemingly simple question: Run the spec oil weight for your engine from your manual. Stick with a top well established name brand oil that is readily available in your area. Do some research on each of the options and pick one. Run it for a few oil change cycles and see what you get. You can change to a different product at any time, no harm done. You will eventually land on one that your engine likes based on overall oil performance between cycles, and one that you like based on your wallet. (nb: the most expensive is not necessarily the best, neither is simply defaulting to synthetics).