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-   -   Oil Question - Is this correct? (http://www.wranglerforum.com/f274/oil-question-is-this-correct-139904.html)

bigegriff 02-15-2012 02:18 PM

Oil Question - Is this correct?
 
I took my 2012 to the dealer yesterday to take advantage of my free oil change. After I got home and began looking over the invoice I noticed they put 5W20 oil in. This has me a little concerned because the manual and the oil cap specify 5W30. I called the Service Department this morning to ask about it and the guy told me that the lighter weight oil is better in the winter because it is thinner. He recommended using the 5w20 in the winter and 5w30 in the summer. That sorta makes sense in theory, but only for cold starts. It shouldn't matter once your engine is warm, right?

Will it hurt anything leaving the 5w20 in or should I just change it out myself?

batster 02-15-2012 02:36 PM

oil change
 
Others on here have complained that putting 5/20 in their 2012 Pentastar will cause tapping in the heads. Changing back to 5/30 is the preferable solution as it is what the engine calls for. What the technician should have wrote on his paperwork is that they were too f-n lazy to care and put whatever they felt like. The 2011 and other 3.8 Liter's require 5/20. 2012 wants 5/30.

kik 02-15-2012 02:44 PM

It's not going to hurt anything. That's probably what they had available. You can put 5 20 or 5 30 in the 3.8. Your 3.6 will be fine.

TOKKIE 02-15-2012 03:58 PM

A quick search on the internet says the timing chain tensioners are hydraulic. So the wrong weight oil could cause issues. I would put the correct weight oil in it to prevent damage. Could not find if the phasers for the vvt are hydraulic, but if they are it will cause timing issues. On the 5.4 vvt ford engines it will cuase timing to bounce all over the place.

Up Hill Bill 02-15-2012 04:10 PM

Quote:

Originally Posted by TOKKIE (Post 2034930)
A quick search on the internet says the timing chain tensioners are hydraulic. So the wrong weight oil could cause issues. I would put the correct weight oil in it to prevent damage. Could not find if the phasers for the vvt are hydraulic, but if they are it will cause timing issues. On the 5.4 vvt ford engines it will cuase timing to bounce all over the place.

So, how do they run before engine oil reaches operating temps (typically about half and hour) when the oil is MUCH thicker than specs? Or when running hot when it's thinner? The viscosity change between cold and hot oil is way more than the differences at operation temp of a 20 grade and a 30 grade oil. Not to mention the differences among brands, dino and synth... :confused:

TOKKIE 02-15-2012 04:23 PM

Here's a good read from amsoil that explains a multi viscosity oil.Motor Oil Viscosity Grades Explained in Layman's Terms

Up Hill Bill 02-15-2012 04:26 PM

Even better info: Motor Oil 101 - Bob is the Oil Guy

TOKKIE 02-15-2012 04:55 PM

That explains oil pretty well. Made me go look in the wsm for the 5.4 vvt, apparently it uses eot sensor to compensate for vvt function.

aelwero 02-15-2012 04:55 PM

go find the mechanic's car and swipe his oil pan plug when he isn't looking...

wait... don't do that... I had a little "help karma along" moment...

You should steal it, have a fit of good conscience, and return it right where you left it...

I very well might put 5W30 in my jeep and ignore the 5W20 written on the oil cap, and I might not bother with a torque wrench when I put on a tire or an exhaust header. I might cut corners on a lot of stuff, but I cut those corners on my own jeep. If I were going to cut a corner on someone else's, I'd ask first, and make damned sure they understood what I was doing and why. Making those decisions on someone else's vehicle for whatever bonehead reason, is just plain wrong.

Up Hill Bill 02-15-2012 05:16 PM

Quote:

Originally Posted by TOKKIE (Post 2035158)
the 5.4 vvt, apparently ... uses eot sensor to compensate for vvt function.

Pentastar must do the same. Lot of links in the chain to keep these things running. :eek: Thank goodness for 5 year powertrain warranties!

OutlawJK 02-15-2012 05:21 PM

Quote:

Originally Posted by bigegriff (Post 2034577)
I took my 2012 to the dealer yesterday to take advantage of my free oil change. After I got home and began looking over the invoice I noticed they put 5W20 oil in. This has me a little concerned because the manual and the oil cap specify 5W30. I called the Service Department this morning to ask about it and the guy told me that the lighter weight oil is better in the winter because it is thinner. He recommended using the 5w20 in the winter and 5w30 in the summer. That sorta makes sense in theory, but only for cold starts. It shouldn't matter once your engine is warm, right?

Will it hurt anything leaving the 5w20 in or should I just change it out myself?

Take it back and tell them you want the correct oil,
the engineers that designed the pentastar engine probably know more than the lazy grease monkey:whistling:

this happened to me at my free oil change and it caused ticking noises
I took it back and had them do another free one

TOKKIE 02-15-2012 05:23 PM

No doubt, these things are getting harder to work on every year. I had never really thought about how all this actually works. The eot does manipulate the variable timing but a direct answer to you hot/cold question is this(out of the wsm).

The lubrication system is designed to provide optimum oil flow to critical components of the engine through its entire operating range. The heart of the system is a positive displacement internal gear oil pump using top seal rotors. Generically this design is known as a gerotor pump, which operates as follows:

The oil pump is mounted on the front face of the cylinder block.
The inner rotor is piloted on the crankshaft post and is driven through flats on the crankshaft.
System pressure is limited by an integral, internally-vented relief valve which directs the bypassed oil back to the inlet side of the oil pump.
Oil pump displacement has been selected to provide adequate volume to make sure of correct oil pressure, both at hot idle and maximum speed.
The relief valve calibration protects the system from excessive pressure during high viscosity conditions.
The relief valve is designed to provide adequate connecting rod bearing lubrication under high-temperature and high-speed conditions.

jp2611 02-15-2012 05:36 PM

If it were me I would have them change it and put correct oil in....I wonder how Jeep/ Chrysler would look on this. I mean you put what you want in based on what you think will work the best...and it won't matter it has the warranty....would it fall under "neglect" and let them out of the warranty?

I am a little anal that way---- if it says to do something this way I do!!

bigegriff 02-16-2012 09:16 AM

Thanks guys, especially UHB and TOKKIE. Those were very informative reads. It looks to me that it depends on the type of driving I do whether a 5W-20 is going to mess with my engine. It might even be better if I take a lot of short trips because it won't get up to operating temperature and therefore needs a thinner oil. I think I might leave the 20 in and see how she performs.

TOKKIE 02-16-2012 09:59 AM

Hey bigegriff, I wanted to know how this engine works so I did a little more research overnight and found out the pentastar uses a torque acuated cam phaser. This link explains the principal Cam-Torque Actuated Variable Valve Timing System - Tech Dept. - Car and Driver. It seams the phaser do use hydraulics and hydraulics are susceptible to oil viscostity, this could explain the valve train rattle others have got when using 5w/20 oil. I would recomend going back to the dealer and have then put the proper oil in.

OutlawJK 02-16-2012 10:04 AM

Quote:

Originally Posted by TOKKIE (Post 2037823)
Hey bigegriff, I wanted to know how this engine works so I did a little more research overnight and found out the pentastar uses a torque acuated cam phaser. This link explains the principal Cam-Torque Actuated Variable Valve Timing System - Tech Dept. - Car and Driver. It seams the phaser do use hydraulics and hydrolics are susceptible to oil viscostity, this could explain the valve train rattle others have got when using 5w/20 oil. I would recomend going back to the dealer and have then put the proper oil in.

egg Zakery:thumb::D


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