Celica Forums General Discussion Engine and Performance Poor idle, engine knock!?

To explain, came out to my car turned it over and it died right away. Tried it a few more times with the same result. Keeping the rpms up with the gas finally got her going enough for me to get home.

Prior to this happening the only thing I noticed is a odd idle, rev up to 2000 then down to almost 500, back and forth it did this for about a minute then it stayed at 1200 for a moment before going to a normal idle. This is where I parked ran into the store only to come out to the problem above.

What I have done so far is to clean the MAF (which I have done aleast 6 times before), clean the TRD filter, reset the ECU, and cleaned the IAC.

After all the cleaning the car starts and stays on but the idle is still a bit off and now I can hear a clear knocking/rattle coming from the engine. I took it out for a short test drive, it drives like shit, slow acceleration that got a little better on the way back. What the hell is that knock?


Does anyone have any advice beyond what I have pointed out, any tips or help would be great. Really afraid the next time I'll need a tow, help.

double check your work.

also howd you clean the IACV?? sometimes when you clean it, the spindle can stick. you have to use a pick and really clean well at each base of the spindle and check to insure it has proper movement. if you didnt do that it would explaing your crazy idle problem.

hard to say what the knock could be.

how do you clean your IACV???

and what is it?

^^^ Idle Air Control Valve

Used throttle body cleaner, sprayed it in the port at the bottom of the TB. I know that is the ghetto way but that did calm down the idle alot, I was afraid to take it apart.



Update for today is that its at Toyota, it drove a lot better on the way there. The idle spike seems to be gone but the knock and the low idle (down to almost 500rpm) are still there.


Not sure what Toyota will say, hope they don't try to screw me.

in the garage forums I posted a big HOW TO thread about it including pics

^^^ You sure did, my only question is how many foot pounds do you tq the TB bolts and nuts to?

Toyota just called...


...could not recreate problem...



I just paid for a $117 oil change, god damn the cock suckers, they always pull this bull shit. Thats right $89.99 just to look at it and I had them change the oil ($27) since they had it and it needed done, so I got a $117 oil change.


All toyota service is good for is brake jobs and oil changes and I don't need them for either one.



Burn in hell Waldorf Toyota!!!!!!!

Your alternater could be bad. Go to a Sears Auto center, 10 bucks to check it

^^^ No, sorry alternators do not cause the problem I have/had, plus my volt meter read a nice 14 volts the entire time I've been dealing with this.

I have the same problem mine idles at 600 below and have been to Toyota 3-4 times and they don't know what it is either. They said it could be the idle control vaccum. But they are not sure. Oh and I haven't been charged at all yet (sorry). I go on thursay cause the idle is above 500 like almost 550.

You need to clean your IACV.


I know that was part of my problem its the knock thats freaking me out, but they can't hear it. I'm going to do a full IACV cleaning like lucky said (love to know the foot pounds for the TB bolts) and change the spark plugs, see where I'm at after that.

can you guys post the link to luckys thread?

they dont need any specific torque spec. just make em nice and tight.

try using seafoam?? I just did earlier this evening and i noticed a significant difference on my idle of my car. and it runs really smoother. I used the seam foam through the throttle body PCV hose and poured some of it in the motor and poured a full bottle of seam foam in my gas tank.

Have you been redlining ur car to the upper 8000rpm and miss shifting. if so, that can be the problem because if you mess up shifting at high rpms the valves would ben

once you check everything you might run some seafoam though the PCV and see what that does for you . but make sure to change the oil after you use the Seafoam.