batstang99

I have a 1999 v6 3.8l mustang. 35th anniversary edition. The car vibrates annoyingly when at idle and while driving. Ive changed both motor mounts and transmission mount. The crank pulley is tight and not wobbling. Drive shaft is in good condition no clinking noises or dramatic wobbling when i checked it.i just cant figure out what is going on. Any suggestions as to what the issue may be?

JimC

This isn't a "forum issue" - you need to post in the correct section. In your case, go to the 1999 section.

This section is for issues with using Mustang Forums.

99GTvert

This is correct. Moving thread to tech...

How many miles are on the car, and has the ignition system been serviced (new plugs/wires)?

batstang99

135k miles i bought new plugs and wires haven't had the chance to change them just yet.

corker

Check out everything first - ignition, fuel and engine mechanicals (compression). I had the same problem with a 2000 Mustang V6. I eliminated all possibilities I could think of and then replaced the Harmonic balancer. I know you said you checked it - I checked mine too. It looked fine, but somehow it had slipped on the rubber insert and threw the whole engine off balance. I changed the HB and the engine was smooth again. I say to check everything before replacing the HB, because it is a dealer part around $350.
Corky

batstang99

Ok i definitely will im trying to eliminate the cheaper possibility before doing HB or transmission.