I have a 95 4runner w/3.0 auto. It is making a noise around 3500 rpm at idle, or just when you need a little gas at cruising speed. It sounds like a stick against bike spokes. Ive been told that the noise it makes is the wrist pin, I dont believe it though as it would do it all the time. Ive also been told that it is the valves, but not to worry about it. The mechanic I went to wasnt to clear on why they couldnt do the work at their shop(valves). He does have a great rep. w/ other toyotas. Also, last night I pulled the codes from the computer and Im getting 12 14 7. Oddly enough Im not getting a bad o2 sensor code considering my CAT fell off about a month ago. Im also running 2 yr. old bosh plugs, which some have told me could cause the codes mentioned above.(control module, and TPS) Ive also been told that it could be the injectors, but it sounds isolated to the pas. side of the engine. Bottom line is I have a lot of work to do and need a place to start.

 

I have the same problem but I feel its sumthing with the exhaust as soon as u pass 3500 rpm it goes away