I've got a rattle that happens only in overdrive and when I'm going up an incline. It doesn't do it in drive,just OD. I think that it may be a valve rattling?Are there somthing that I can do,or do I need to get it looked at?? Thanks

 

might be spark knock

are you running 93 octane gas?

 

I was until,gas around here got to 3.00/gal for 93. I have been running reg/mid here lately.