Jeeper John,

Last week with the temps in the metro area i had the same issue.

This has also happened to me after coming back from a hunting trip and the jeep not starting for 4 days.

It is quite a sound to hear under the hood, but so brief. Maybe two seconds in my cases, MAYBE.

Come to think of it, i have never had a dry start in the summer.

 

I also have the same issue with my 2011 JKU Sahara (15000km) . It only happens when its really cold out and living in Canada I am no stranger to cold starts. Has anyone found a filter with an anti drain back rated for cold weather? I think the silicone valve gets sluggish as the cold sets in the engine. Add that to highly viscous oil and you get a recipe for an oil starved engine in -15 weather. Is there a diagram somewhere for the 3.8 that shows the path of the oil through the engine?

 

Also living in eastern canadas fridgid weather. I've found running synthetic and the Fran filter gives me the least dry starts even in -20, tryes Mobil 1 and Quaker filters both almost always had dry starts

 

Try 5w-30 it worked for my 10 Rubicon,
Did not believe it till I tried it....

 

I have a 2009 X and had the same issue of a "rattling" sound at startup. It would only last a second or two and would not happen again unless the jeep was turned off for at least 5-6 hours. To make a long story short, now less than a year later, I have a new engine installed. Turns out at least one of the valve guides was bad and would allow the oil in the valve train to leak down into the cylinder overnight. That explains the ticking and the occasional puff of smoke on startup.
The ticking sound is a dry start of the valve waiting for oil from the pump.
Engine was consuming oil. After two separate 500 mile consumption tests, first showing .7 qt and second showing a full quart, (1.7 qts in 1000 miles) they agreed there was a problem and started an investigation breakdown.
Some of the things they found:
2 heavily carboned plugs
No vacuum leaks
PCV ok
Heavy carbon and scoring of two cylinders
Heads tested and would not hold compression

After this point, they knew it need to be replaced...

When removing the the old engine, they dropped the oil pan and found the remains of an oil control ring.

The Jeep is great now. No more hesitation and has quite a bit of pep! And the best part, no more ticking on startup!

It took two months to complete the oil tests, (short commute to work) and then the jeep was in the shop for 30 days before I got it back.

Jeep started ticking at around 35000 miles. Engine replaced at 38000. Now at 39500 and all is great.

For those that need to know, here are the particulars for my Jeep.
2009 X
6-speed
Shell or BP regular gas only
Castrol 5W20 and a K&N oil filter (changed every 3k miles or 3 months)

 

my 2011 has a rattle for less than a second if its below -10C and I dont have the jeep plugged in, has done it since I bought it, this is running regular 5W20.

My TJ with a 4.0 used to make alot of racket it wasnt plugged in at those same temps too.

 

I just posted a start up tick thread. For about 1-2 mins at start up I also get a tick shutter 5 w 30 with a fram filter did not help :(

 

My new Jeep has less than 75 miles and is not my daily driver. Its not that cold in Richmond Va. but last nite (after sitting for 24hrs) I start it up and got out to check the tire pressure and got no further than the front tire and reached in and turned it off. I have never heard an engine make that much noise other than one that someone forgot to put oil in it after an oil change (I will not share who that person was but you might guess) check the oil and its full but man it did not sound right to me! Started it back up and it took way to long for it to stop rattling IMO. Drove around for a while then stopped went into the store came out and restarted not as bad but there is some fundemental issue here that is not right. I get a new company vehicle every 3-4 years based on mileage. Ive always gotten F-150s Im on my 3rd. Ive never heard this kind of racket out of a new motor. My Jeep will be making a trip to the Dealer real soon WTF

 

Mine did it the other day for the first time. Scary stuff I got real nervous then my friend distorted his and the exact same sound. So now I'm not as worried

 

Did jeep pay for the new engine? Because I have all the same symtoms but I have an 08 with over 50K miles; if not I think it's time to trade it in for something else, man and I love my jeep.