Rattle on Acceleration

2001 4cyl. ext cab tacoma, 4x4, 100,000 miles

I've got a subtle rattle from about 1500 to 2000 rpms, light to medium acceleration. It almost sounds like a ping but it's light and more inconsistent. Once I hit higher rpm's it goes away or if I take my foot off the gas it subsides. It's audible and I can't feel any vibrations or anything with the rattle. It seems to be underneath the truck and towards the passenger side.

The sound is only during acceleration and doesn't do it while reved in park. It's gotten a little worse over the past year or so. I cannot find any loose heatshields and when I bang on the Cat I get a little rattle but nothing too bad. Should there be no rattle at all from the cat?


Anyone have any suggestions to diagnose where the sound is coming from? Any thoughts or things to elminate right off the bat?

Thanks!

 

Only because it would be an easy experiment, I would suggest the same thing. Let your tank go almost to E and then refill with premium.

My V6 doesn't like 87 octane going up hills in 4th or 5th gear.

Is yours an automatic? If it's pinging and its a stick, it most likely won't happen in first gear and maybe not in second either.

 

Great recommendations by the members here. My brother had a '02 4cyl. that started to ping when once it reached over 125-135k miles. Using 89 octane cured the knocking that he was hearing. You can also try using one step colder spark plugs to see if that can help.

 

If it sounds like the rear part of the truck could also be a U joint but i kinda doubt that as it would be screaming if it's been going of for a year. Carrier bearing is possible too..but again woulda gotten worse.

 

My u joint went bad and caused no vibes..just noise. Only at acceleration and due to being a manual when just letting if the gas it would make noise too.

Need more info to really know. But ya could be pinging. I don't remember you ever saying yours sounded like it was under the truck. That's what made me throw up the u joint possibility.

 

Yea mine too. I knew it was under the truck. Took a while to figure out it was in the rear.

But if your saying you could hear it in front of you that'll be the give away as to where he really hears it.

 

Could be. Like I said in my original post. I doubt it's the u joint as he said its been going on for a year. A bad u joint for a year would be screaming by now.