Jeep Wrangler Forum banner

Pentastar rattle

12K views 26 replies 19 participants last post by  Riccochet 
#1 ·
I have a 15 Jku willys with the 3.6L engine and manual trans. In the morning when I start it there is a rattle for 1 - 2 seconds until the oil is picked up and then all is quiet. Only does this after sitting for a few hours.
My wife has a 15 Dodge journey with the same engine and it does not do this. Yes the oil is full and clean only 1300 miles on the jeep. Should I be concerned or is this fairly normal.
 
#6 ·
Mine is pretty quiet
 
#8 ·
My '14 runs smooth and quiet from start up. However...I did notice my previous '12 had a little clatter.
 
#13 ·
Some do it and other don't, so it's anybody's guess.....:confused:

It has been stated by several Forum Members, that running 5W-30 seem to help at start up!!!!!!!
 
#15 ·
Mine used to until I switched to Pennzoil Platinum 5w-30 synthetic. Now I don't hear it anymore. I was concerned about running it in the winter but even cold weather starts were quiet. I'm sold. I even put it in the truck on the last oil change.
 
#16 ·
^^^X2, same oil and viscosity that I am using!!!!!!!
 
#17 ·
my 2011 dodge caravan with the 3.6 did that. had it for 3.5 and 53 000km and no issues.

My 2014 jku is quiet after I did my own oil change and used 6L of quakerstate.
 
#23 ·
My new 3.6 does not do this, but my wife's mini cooper is notorious for doing it. Turned out to be the hydrolic timing chain tensioner. It needed to fill with oil on startup in order to tension the chain enough not to rattle around on the top pulleys. The fix from BMW was a longer chain tensioner to keep the timing chain tighter.

I'm not sure if our Pentastar engines have the same type of internal tensioner.
 
#25 ·
Maybe it depends on the climate where you live. I live in South Florida so it rarely gets below 60 degrees during winter.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top