I'll do my best to explain this. 02 Taco 3.4L, 22k miles. As it's started getting warmer, I've noticed my valves getting noisier under load at low RPMs. (Not bogging the engine, but not in the power band either). At first, it didn't seem to be too bad, but it has definitely gotten worse. THEN, yesterday I was stopped at a red light, and when I took off it was TERRIBLE. Bad enough that I pulled off the road and checked the oil. It literally sounded like no oil was getting to the rockers though. Oil was fine (800 miles since last change), so I start it back up, take off and it's back to the way it was--which is noisy, but nowhere near as severe as what I just explained. I have not been able to duplicate that again. Anyway, oil is good and clean, there seems to be no decrease in performance (even during the severe fit that it took). Someone please tell me what I'm dealing with here. I can't believe I'd be having this problem on a Yota at 22k miles, and I definitely don't understand what would cause an intermittent (or one time deal) severe valve rattle.

BTW, air filter is new (changed at last oil change), coolant is right on the money, basically it's a brand new truck--although just out of warranty, I think.

Thanks for any help/opinions!

 

what weight is your oil? Because its happening more now that its warmer it sounds like it may be that your oil is thinning too much

 

if your valves lost oil it would have wiped every lobe on the cam.sounds like preignition to me.mine does this too,but only in the summer and with the A/C on.

 

I'm using Amsoil 5W-30 full synthetic, changing at about 5000 mile intervals. It's been pretty cool here the last several days, and no significant noise from the valves.

I run 87 octane gas, but have never had a problem with it. I'll wait for the weather to warm back up and see what happens.

Thanks for the replies.

 

Switch to a thicker oil for the summer and see if that remdies the situation;my Eclipse didn't like the thinner stuff in the heat.

 

try 10w-30 but that doesnt usually make a severe diference in sound. A mild difference yeah but not from no noise to severe valve train noise.

Are you sure its valve noise? If seen alot of things make things that sound like bad valve noises, from tensioner to warped exhaust manifold. Can you hear what sounds like ALL the valves?

That about taking it to the dealer, is it under warrenty. I dunno if they had the 6year 60k powertrain like they do on my truck.

 

You shouldn't have to change the weight of your oil on a 22K mile vehicle due to noisy valves; 5-30 is standard on this engine. If the sound is severe enough to be concerned, you need to take it to the dealer since it is still under warranty.