Slight rattle

[JRThomas]

I have a slight rattle like the pre ignition you get when you use low octane gas in a gas engine. It is very faint; you can’t hear it with the windows open, radio going or the wife talking. You only hear it while running at a steady speed on flat highway, if accelerate, decelerate or start up a grade it goes away. I usually get the rattle between 1500 to 2000 rpm’s. It never changes frequency. This has been going on for the last 30k miles. The truck runs great and I have had no problems since day one. I bought it new.

I have 55k on the clock, 50k with my normal towing load of around 10k. I get around 10. 5 mpg towing and 15mpg without towing and in city driving.

 

[rbattelle]

You might try running a tank with a cetane boost and see if that clears it up.

I wouldn't worry about it, though.

Ryan

 

[GDMRTN]

A friend of mine just had the same thing. It was one of the trans oil pump bolts come out. No leak. just little rattle at certain odd times. Mite be something to check.

 

[JRThomas]

Thanks for the ideas. I’ll make a close inspection tomorrow.

I changed the FAC today, but won’t be making a trip for a month to check it out. I found it out a little too late, but even with my employee discount it’s cheaper to get it from Cummings.

 

[rbattelle]

FAC? You mean FCA? What made you want to change that?

Ryan