2012 Pentastar Noises on Started With Jasper Remanufactured Engine

NowieHowie

New Member
Joined
Aug 20, 2025
Messages
1
Location
Michigan
Last winter I had a shop replace my 3.6 pentastar in my 2012 rubicon with a Jasper remanufactured pentastar.

Since I’ve gotten it back a few months ago upon start up the engine has a whine that seems to be following the rpm’s until it warms up enough. Doesn’t even need to reach low pressure on the oil pump, just once the engine warms up a bit the noise stops. Wondering if anyone can diagnose and suggest a fix.


Some background:

After the engine install the first issue was some harness problems, had to repair that due to losing all power if the jeep jostled too hard. Then I noticed the jeep had a very low oil and very high coolant situation and they said they replaced the water pump along with fittings and tubing. Had a similar noise before the pump exchange but it changed a bit and evolved to what it is today. I left it with them to try and diagnose it but they said they couldn’t figure it out.
 
I'll play the Devil's Advocate role on this one. I'm still trying to find the root cause of my noise. New Gates belt, idlers, and tensioner didn't solve it, even though one idler had a bad bearing. I have yet to find it with the stethoscope. My suggestion would be to not throw parts at it until you can pinpoint it.