2011 Wrangler Unlimited, 29000 miles. Factory Spec engine oil. This vehicle is not a daily driver. Consequently, it is not unusual that she will sit without being started for up to 7 days. At the end of these periods, only on initial start, I get a racket and shaking emanating from the engine compartment. This will last only for 1-2 seconds. Unnerving to say the least. I am using oil filters which are advertised to have an anti drain back valve. At the next scheduled maintenance I plan to take this up with the dealership. I have very low expectation of help from them, however. Anybody have any idea on what is occurring in the engine? My concern is engine longevity. Thanks
Over Hue PhuBai RSVN. Summer of 1967
There have been quite a few threads on "dry start" sounds with the Pentastar 3.6. I recently read someplace that the new 3.6 is using a different oil filter so Jeep may have changed the design a bit for this issue... Valve clatter on start up.
Brian - ACØUS
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I had a jenyoowine Mopar oil filter installed today. We'll see.
I had same issue with my 2010 3.8 even sitting for a day at first. Wix or mopar filter will help, but letting it sit for a week or so you might still get some clatter on initial startup. I notice it more now in my garage that my hardtop is off. I don't think you will do it much harm, but you appear to be a car guy so here is what I do. Run synthetic oil "platinum ultra" with a K&N HP-2009 oil filter, its aprox 35% larger than the stock filter and its designed for the 3.7 jeep motor. Same specs for valve and size clears everything fine. Excellent filter in my opinion and a little extra capacity. Mine will clatter after sitting for a week though too. If you really want to eliminate noise/startup wear this AutoEngineLube Pre Lube System Reduces Engine Wear Up To 60%. I'm not running this because currently only driving my jeep 7k a year, and at that rate I don't expect to have an oil related failure in a time frame that would justify it. You appear to be a vet thank you for serving and take care.
Also, I prime the oil filter when I change them. I fill it with oil and let it soak in. I then pour out what isn't trapped in the filter media back in the container. Other wise with the horizontal position of the filter it would be a big ol mess instead of a minimal mess as you screw it on. This helps minimize a really hard dry start every 5K or so when I change the oil. That sump system might work really well for off roading with sudden pitches of the vehicle and the oil pickup possibly starving at times. I used something similar "accusump" on my 69 Z28 back in the early 80's, but oil related issues with that vehicle were due to sudden braking and accelerating and cornering back then. Then again spinning it to 8k and speeds up to MPH didn't do much for engine longevity either............
I realize you have the 3.8, but also notice this with the Pentastar when it sits for a week. During the winter, it might be sitting for longer periods of time. My warranty period is going to expire before I get anywhere near the mileage cap.
Has anyone made an ignition cut-off so you can crank the engine without it firing? This used to be easy in older cars, but might be more difficult in new ones. Basically, it lets you spin the engine with the starter to build up oil pressure before you flip the switch to let it fire. Seems like it'd really help in the new stuff that fast idles to build catalyst heat.
There are aftermarket pre-oilers as well, but I think thats a much more involved process.