2000 Ford Mustang 3.8L //// Engine Vehicle Shakes entire front end of car when at idle, all the way up to 2,000 rpms then it goes away. Starts right up, had problems with a few computer codes fixed all. Still did not fix problem, now if you unplug most of the sensors no check engine light comes on or change to the engine. Yes light does appear when you fist turn ignition on. I have replaced many sensors and all so the torque converter for no reason. Everyone I talk to has no ideal what it could be. just checked the Harmonic balancer, by taking the Serpentine belt off still does it.. all so no movement in the balancer itself.

  • At this point it shakes the front of the car but doesn't set and fault codes?
    – mikes
    Oct 1, 2013 at 23:13

2 Answers 2


From some information I have gotten from several Mustang forums 3.8L come in two varieties. An externally balanced and an internally balanced variety was available. Model year 2000 was change year. 1994 thru 2000 were externally balanced. 2000 1/2 and up are internally balanced. What all this means is if you use the wrong flexplate the motor will shake as the rotating assembly (crank, pistons and rods) is unbalanced. This would explain the lack of fault codes as fuel, air and combustion are normal. You need to verify when the motor was built and that you are using the correct balancer and flexplate.

  • Yes that's true front of car shakes and no codes, checked codes the other day, and still none. vehicle is a 01/2000 which is listed on the door. The other question I have is when I droped the cerp belt and tried to wiggel the harmonic balencer no movement at all or nor does it wobble at all when i started the engine with out the cert belt on ??????
    – Raymond
    Oct 2, 2013 at 14:45

If there is no wobble in the harmonic balancer, and you can see that the rubber between the crank and the pulley part of it is ok, I bet you have a bad or tweaked motor mount. Motor mounts can typically be checked with a close visual inspection while somebody power brakes back and forth from forward and reverse.

Unplugging the sensors didn't throw a light right away because most electrical issues need to occur twice to turn on the light.

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