engine knocking in '01 Taco 2WD

Hi there,

I've got some knocking in the engine at low (idle) RPM 700-750.
Sounds to me, the valves are tap dancing. Nothing while driving, excelerating, etc. Good mpg.
The engine is the base one for 2WD Tacos, 2RZ, 4 cyl, 5speed. It has 15K only. The dealers say it is some carbon-...whatever build up, very common with this engine, caused by the inexpensive gasoline I've been using. Doesn't burn any oil. They say it is not the valves, which can't be adjusted, anyway.

http://www.CustomTacos.com/ubbthreads/images/icons/confused.gif Please, advice.

dan

First, welcome to the site. Second, valves can and MUST be adjusted from time to time (see your maintenance schedule). Is it sort of a rattling sound, almost like a rattlesnake? If so, it's normal. Damn near every Toyota pickup 4-banger makes this noise. Both of mine do. Carbon buildup common to this engine? Never heard that before. What kind of gas are you using?

Hello,

You see, I live among the rattlesnakes (SoCal desert), but I've never seen one; and I don't want to. Therefore, I want to say "yes" to the rattlesnake-like noise, but I'm not certain. The tap-dancing, or just simple knocking that I can almost count, is the best way I can describe it. The description tap dance came from another Tacoma site (enclosing the link), which particularly mentiones one of your engines. So, I thought, it is probably the same or similar issue. http://bcoffroad.250x.com/engtran.html
It is just hard for me to believe, that the valves are already loose, at 15K miles.

I've been using the cheap gas from Costco ('86, or '87). After the dealers told me about the buildups, I switched to Chevron & Texaco '89. Noticable difference in MPG. Two dealers, the local and the one in Moreno Valley, are selling me the same story. The one in Moreno Valley, offered to run some kind of "marvle" ( I think) oil, designed to clean it up.


Thanks,

Dan

To anyone checking, that website has a few corrections to be made (I've seen it before, via http://www.off-road.com). The 22RE-T (aka 22R-TE and 22R-TEC) was not just available with an automatic, it came with the greatest Toyota transmission ever, the R151F 5-speed manual with a 4.31 1st gear. Also, it's around 135hp, not 145hp. Lastly, getting 20mpg out of it is an excercise in futility. http://www.CustomTacos.com/ubbthreads/images/icons/smile.gif

I've used Marvel oil in the past, both in the motor and in the fuel system and it worked well for me. However, if you are having real problems with this new of a motor, the dealership needs to address it. Many 4cyl sound like they have a knock (tapping) when at idle. Toyota motors are famous for this. Doesn't mean anything is wrong, just the nature of the beast. They can check the valve clearance and make sure all is buttoned down correctly, but if I were you, I'd hop in another Taco of the same drivetrain as yours and see if it sounds the same. Then, take it from there.

sorry to hear the dealer bowin smoke up your hieney on the valves.....they are adjustable....however its not as easy as the conventional tightening/losening a bolt to adjust the gap....its done with shims.... sounds like they are trying to get out of a warranty job.... but definitely stick with the better gas...i did a full valve job @ 60K....and the guy was amazed @ how good things actually looked.... my carbon deposites were minimal.....also i would recomend replaceing your fuel filter and running a bottle of techron through the tank.....i know it seems early but cheap gas does tend to gum up filters and lines quick.....goood luck and stick to your guns... have the stealer check them valves b4 you have a bigger problem on your hands and you dont have a warranty to stand on... http://www.CustomTacos.com/ubbthreads/images/icons/wink.gif http://www.CustomTacos.com/ubbthreads/images/icons/wink.gif

Did the Techron already. I guess, I'll have to change the filter.
Shims.... that's right. No way dealer would do this under warranty, wouldn't they?

Thanks,

dan