engine not running right

[Taytum98]

Hi guys, when i start my engine up it sounds like a vibration noise when its running in park. Sometimes the sound might ease away for awhile. You can hear it good when the engine is hot from driving. I haven't change the heads yet and never replace my water pump yet. Never ran hot on me yet.I don't see any white smoke coming from tail pipe. Could it be signs that my heads are starting to go. They leak a little oil but not where i have to add any. Any feed-back, thanks!!!!! 99 disco 1 SD auto. 121,500 miles

 

[joey]

Vibration noise... pop the hood and use a mechanics stethoscope and find the offensive vibration.

 

[Disco Mike]

Could be a heat shield, bad cats, broken flex plate, broken motor mounts or any number of issues. As Joey has suggested, get under the hood and start searching. I would suggest you don't drive it till this problem is found and fixed.