This is why i asked him to confirm.

 

Costco fuel... I'm going to run a can of Seafoam through it and try Chevron or Shell gasoline. If that doesn't help I'll have the timing checked.

The car is stock, 57k, I bought it from the original owner at 50k, all service done at the local Infiniti dealer.

It's not a rattle.

Thanks for all your help guys.

CM

 

Costco gas is your problem.

 

It's a possibility that it is the Costco gas. I've had bad experiences with it.

Give it a few tanks of "better" gas before you evaluate. I wouldn't even do the seafoam. Just run some fuel injector cleaner and different gas and see

 

I used Costco gas for years in my 04 and never had this problem. However, their supply chain is regional, so I guess it's a possibility; winter gas in general seems to cause alot of problems. My guess is carbon buildup or a sensor mis-reading; I'd recommend the fuel injection service the dealer offers. In addition, reset the ECU at the same time.

 

It's the gas. I last filled with Shell 89 octane, runs like a champ. I guess you get what you pay for. I'm still going to run a can of Seafoam through it just to clean it out a bit.

Thanks for your help!

Carl

 

are you pumping Costco premium or regular? I pumped Costco premium for about 2 years.. zero problems.

 

C mare. Only run a half if you never have run it before! It will freak out your O2 sensors!