My 1999 Toyota Tacoma vibrates badly during idle speed. I've taken it to a few mechanics and they were unable to fix the problem. One mechanic suggested changing the engine mounts. This fix didn't change the vibration. The truck only gets the vibration after the car is warmed up and once the RPMs drop below 1000. The performance of the truck isn't effected by the vibration, its just annoying for driver and passengers. Any ideas?
It sounds like it's missing.
Have you pulled codes to see if the computer is trying to communicate with you?
Your truck is OBD II compliant, this means you can plug in a scan tool and see what the computer thinks might be problematic. AutoZone will pull codes for free, or give you the scan tool and let you do it. The data port is located along the bottom of the dash, either completely exposed, or stashed behind a cover that is clearly marked as containing a dianostic port behind it. When you find the data port, it will remind you of an LPT2 printer connector, except it only has 16 pins instead of the 40 pins found on the printer. The look and feel of the pins is similar, that's why I describe it that way.
Your truck can feel bad, and store a diagnostic code, but NOT turn the Check light on. I think any problem that causes rough running at idle would set the Check light on, but you should pull codes to see if the computer knows something is not right with the universe.
Dan, I have an '07 Tacoma 2.7 L with a similar problem. The truck only has 7000 miles on it and it ides very poorly when it is warmed up. The idle is about 600 rpm If I increase the engine speed just slightly , maybe 50 rpm with the gas pedal it will smooth out. I have had it to the dealer and they tell me everything is in spec and that no bad codes were found. Basically they told me thats just the way it is. I called Toyota customer service and they told me 4 cylinder engines idle rough and it it doesn't bother most people! Well ...... It bothers me and I plan to fix this one way or the other. The real problem with this truck as I see it is that you cant adjust the idle even a little. It is controlled by the computer and if the computer says its OK then it must be OK. This may not be relevant to the 1999 Tacoma but I thought i would follow this topic for any ideas
joel
I think a couple of weeks ago a 2.7 owner commented how smooth and quiet the engine ran. Must be manufactured by a different Toyota! ;)
Engine mount was a reasonable suspect. Also fuel injectors, fuel filter (restriction), plugs, plug wires, valve clearance, timing. Just some thoughts.
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