Guys, i'm continuing to have issues with what I think is my timing chain. When ever the the vehicle is under load (I mean going up a hill at 55 mph)it has to downshift. Right before the downshift, there is a kind of chattering sound....almost like someone is crushing a can or something and i believe its something within the engine.

It doesn't do it when the engine is just sitting there and you rev it, you have to be driving and it only tends to happen when trying to keep a steady speed and climbing a decent hill......

Any idea what-so-ever would be greatly appreciated...I just can't figure out what it could be from.....

 

How many miles do you have on the engine? My wifes '97 tacoma (2.7L manual shift) had a promblem that when you put it under a load it would miss quit a bit, so I put new plugs in it(NGK) and not a promblem yet. By the way hers has 150,000 miles on it and with the new plugs it runs like new. Seems to me that if it was the timing chain it would do it whenever you accelerated.

I wonder if it could be in the tranny?

 

Sounds to me more of an automatic transmission issue, or clutch issue than a motor issue. Just make sure you completely rule out the possibility of the transmission before you go tearing into your motor.
good luck.

 

Yeah its a 97 4runner with just under 130000 miles....see I replaced the plugs last summer though unless one of them is bad or something. I guess it would be relatively inexpensive to at least try.....I also thought it was a manifold leak but I replaced the manifold cause it was cracked and it helped but didn't fix the problem.

If it was the auto...wouldn't it do it under normal shifting too. It shifts perfectly otherwise though.