Yes you can use CJ-4 oil if you want to use it, but if you want to extend the drain time on your oil then use CI-4+ oil as it has a higher TBN number and will last a lot longer.

 

I have exactly the same thing on my 2005 with ony 6000 miles on it. It started about a week ago. The best way to describe it is similar to pinging on a gas engine. Definately coming from the right hand side of the engine. Not temp related by any means. I think I'll bring it into the dealer next week.

 

I'll get that same ping, had it for about 30K, the one thing Ive found to get rid of it or make it not as loud is to hammer the throttle a few times and let the rev limiter take over with a load.

the mix helps out alot, however carbon will still build up on the injectors and this is what you are hearing.

 

That much of a buildup after only 6000 miles? Seems strange, but could be I guess.

 

if your not getting high cylinder pressures and pushing the EGT's then it wont take long to build up.

 

6000 miles on the 365 and the intake manifold ports are 3/4s of what they were new.