07 4.6 rattles under load

[RonZonk]

My 07 4.6 with 90k miles has just recently begun to rattle under load- hard accelerating or a moderate hill while towing ~3500lb of boat & trlr. I have this list so far:
timing
EGR
MAS
so yes, those contributors are related... just wondering if anyone here has had that issue with the 4.6. I have cold air & cat-back, but no other engine mods.

 

[07LTDDSM]

you sure your intake is not rattling? try taking it off and listen for noise.

 

[kvunck]

Yes mine also rattles ( pings ) I have found that mid grade fuel use while towing is the best bet.

 

[JohnnyO]

Yes mine also rattles ( pings ) I have found that mid grade fuel use while towing is the best bet.

It is probably the gas since it just started doing it. Different parts of the country get different blends of gas at different times of the year. Here we get the crappy oxygenated gas in the summer, I see you are in IL so it might be the same for you. I've had it affect some cars more than others. My 4.0 Sport Trac doesn't care much but runs better on 89 in the summer. I used to have a 3.0 Ranger that would barely run on the summer gas and pinged like crazy despite multiple trips to the dealer to have it worked on. Had to use at least 89 and 91 worked better. Then in September we'd get normal gas again and it was fine on 87.