wuzwiz

My new jeep ('17 JKU) makes a lot of noise on startup. Sounds like the lifters are collapsed and starving for oil. Soon as the oil comes up, all is well and we're off and running. My '07 w/ the 3.8 was weak but ran 120,000 with no expensive noises. Anyone else???

2MchFun

My '16 does the same thing. Hopefully, it's not as bad as it sounds.

Punkineater

My 14 does it as well.

cidd

My 16 is quite as a church mouse

Cajun JK

My 16 Willys and my wife's 16 KL Trailhawk makes noise at startup.

mr72

My 2015 has been noisy for the first 2-3 seconds on startup since day 1.

BTW the Pentastar engine doesn't have lifters. It does have cam followers and other things with clearances in the valvetrain.

The reason it makes this noise is because oil has not been pumped to the top of the engine yet. It has to turn over a few times for the oil to make it up there. The oil just dampens the noise. The "dry" parts rattle/clatter, but when oil is on them they don't make as much noise but they are still moving the same amount (pretty much).

Seizer

Is this a noise that may be solved by an anti-drain back valve in the oil filter? I don't know a lot about fluid mechanics, and yes Archimedes principle I'm sure is at work here, leaving the top end without fluid. Just my 2 cents.

mr72

It wouldn't really apply in this engine, and there is no such filter available anyway.

And the noise is not really a problem that needs to be solved. It's just a noise the engine makes. You're not going to wear out the engine rapidly two seconds at a time every time you start it due to too little oil on the cam/follower/valve.

My daughter's Fiat 500 is more annoying in that it has an electronically-actuated valvetrain that won't turn on until oil pressure is above a certain point, which is a chicken and egg problem that results in the occasional no-start condition. Cars these days. Makes me love my motorcycle quite a lot.

Mr.T

On the 3.8L I've noticed the quietest starts with 0w-XX (my preference being 0w-40) oil. 0w-XX viscosity oil has better cold flow than 5w-XX, but the hot -XX viscosity is what it is, regardless of the w- number.

Regarding oil filters, I'm noticing that filters with finer filtration than OEM (and are more restrictive) tend to cause startup noise - especially in winter. Switching filters is a quick test.

mr72

just bear in mind the 3.8L is not much like the 3.6L. Apples and oranges. What makes noise in one won't necessarily make noise in the other, filter types are not nearly as available for the 3.6L and oil viscosity is somewhat different in terms of applicability because tolerances lubrication design is quite different. Not only that, at higher revs a higher base stock viscosity may be important and the 3.6L revs higher for sure.

That said, besides the warranty considerations, a 0W30 or 0W40 oil is probably best at least where I am at (Central TX). They specify like 5W20 for fuel economy mostly. I'm running Pennzoil Platinum 5W30 and it makes noise for 1 second or so on startup.