Skrillah

Ok boys, got a little problem here....whenever I accelerate hard....mostly from like 2nd to 3rd and the engine is working hard to get me up to speed, there is a chattering type sound. Its a 97 runner with 127k on it, to my knowledge the timing chain hasn't been replaced and I'm thinking that could be the problem? If I don't kick it as hard its fine, and it seems to be fine when i rev the engine in neutral too, just mainly when i'm headin up hills or i really punch it and it has to shift. I should mention its a 4cyl stock engine.

Skrillah

also....its an automatic

BajaRunner

Sound kinda like a noisy valve or exhaust leak? I have that same problem when accelerating hard.

Skrillah

Yeah I'm not sure...something like that.....

FUZION

I have a similar ugly sound under hard acceleration on my 4cyl, my mechanic said there was an exhaust leak in the engine bay area

Skrillah

Oh really? Did he say it was anything to worry about and hopefully and non-expensive repair?

FUZION

I don't know how much it would be to fix. He did say no to worry about it though, it was more of an annoyance than anything. He's trustworthy as he's been a friend of the family for some 10 years and works on porsches, ferraris, toyotas, peugots, ect...and has owned his business for some 15 years.

Skrillah

Hmmm....good to know....I thought surely its not the chain. Its gotta have a lot more life left on it, after all it is a Yota with not awhole lot of miles!

Unhappy99

If it occurs when working hard, that could mean the engine is knocking due to detonation. Although not cheap anymore, something quick to try is the next grade up fuel. Warmer ambient temps may require higher octane fuel.

Rick F.

Any chance it's engine ping? My old 3.0L was notorious for engine ping under heavy load. A little timing advance and/or an occasional tank of 89 octane seemed to help.

Skrillah

Nah, its not really a pinging sound....hard to describe the sound....kind of sounds like a small bird flapping its wings under the hood for like 2-3 secs. I know thats a weird analogy but its the best I got...haha . During the cold winter months, I always used 93 oct. and honestly now that I think about it, don't remember hearing it. Maybe that is it, just needs that higher octane.......I'm thinking now its an exhaust leak somewhere....looking around and that seems to be a problem some ppl have....

gpcollen1

It could be just a loose heat shield around the exhaust or something like that...that is what mine was. It was toward the mid-rear of the vehicle and still sounded like it was under the hood...

Slide under and take a look, touch some of the items under the truck, get to know her intimitely...

That is why I bought a creeper recently - so I would not hesitate to do this as a quick first step in diagnosis - and to avoid scrapes and sore spots on my shoulder blad

Tacoclimber

Just to throw this in, on my 99 Taco with the 2.7, I had an exhaust leak on the manifold that sounded similar to what you're describing. When I punched it, I would hear it, but if I just cruised, I really didn't. I asked a mechanic friend of mine as well, and he said the same as your friend. I never worried about it, and it never got worse and never caused a problem. Just some food for thought.

Skrillah

Yeah sounds like its not a big thing to worry about, I'm just glad you guys aren't writing back saying "yup, sounds like the timing chain is going!"!! I'll check it out a little more and see if I can see anything obvious, but unless it gets worse...I'll let it be. Although, I was thinking about throwin a nice exhaust system on anyhow, so we'll see! Thanks a ton guys for the feedback!

DavidA

My 22RE on my old truck did that....turned out to be the timing chain guides had worn through and the chain was slapping around.

Skrillah

The new question is though, i don't seem to hear it when i rev the engine at all....just during actual driving....?????? What the heck does that mean?

FUZION

I'm going out right now so I'll see if thats the same with me.