I noticed that my truck may had developed an intake manifold gasket leak and tested it with throttle body cleaner to find it indeed was leaking. I decided to wait till I got back from Uwharrie as I'd pick up the gaskets from Jerry while there.

My truck had always had a slight vibration. My dad's trooper does the same thing, not super annoying but it's definitely there. My issue started upon coming home from the trip to Uwharrie. I was in Virginia I believe and got gas at sheetz. I started my engine up and put it in gear and noticed immediately something was different than when I shut the motor off last. The engine was vibrating a lot more than it has previously and while I was a bit concerned at first I figured it was either bad gas or just my truck reminding me to do the intake gaskets.

Long story short it's now been about 6 months. I've done my intake gaskets, leak there is gone. I've done my fuel injector o-rings, leak is gone. I found a vacuum hose split going from the manifold to fuel regulator, fixed that. Still... After all this and only slight improvements, the engine is still idling very poorly.

Here's what my symptoms are like: it only vibrates bad when it's in gear, more vibration when under more stress (no vibration in neutral, 3rd gear least vibration, followed by reverse, 1st and 1st LOW Range) if I let the vehicle start to roll the vibration eventually goes away without any acceleration or opening of the throttle. If I hold the brake and open the throttle a bit, the vibration does not go away the motor feels very heavy or bogged down for lack of a better term. If you're at a complete stop and throw it into neutral the RPM drops down almost stalling then comes back up to normal. Occasionally when starting the engine it'll surge, but that's very rare.

Everything I read says I'm looking at a vacuum leak... I don't know where else to look though, everywhere I look either seems fine or has been replaced. I just ordered a new EGR valve and will try that. After that I'm thinking maybe fuel regulator but I'm not sure.

If anyone could be so kind to tell me the silly thing I'm missing that'd be awesome! It's kinda embarrassing, I had a friend in the truck the other day and we were at a red light and he asked why my truck vibrates. I simply stated it was just my motor mounts getting old :mrgreen: rather than saying "I HAVE NO FREAKING IDEA WHY" and following that up with uncontrollable weeping