1990 4.9L Straight Six (Missing Head Gasket)
I posted this in the V6 section, but thought I might be able to get more info here.
I'm new here, and need advice/suggestions on how to resolve an issue with my truck.
About a week and a half ago, I was heading home, and I lost all oil pressure/truck died. Started truck up again, ran fine for about 5 minutes, died again. So, I had the truck towed home.
I checked the oil, and to my dismay, I found a bunch of burnt antifreeze. Blown Head Gasket, right? Wrong.
Pulled the head off, and guess what? I didn't have a head gasket (seriously). It was obvious someone had rebuilt the engine in the past, and deliberately left the head gasket off. The really odd part is, that I'd had this truck for 2 1/2 years, with no problems at all.
So, I replace the head gasket, put it all back together, and it starts/runs like a champ.
The problem is, now when I put the truck into gear (it's an automatic tranny) and leave my foot on the break, it shakes the bejesus out of the truck, especially in reverse.
Once the truck gets up over about 5mph, the shaking goes away and it drives fine.
I've checked the plug wires to make sure they were all connected well. I've made sure the motor mounts are very secure.
I'm going to do some checking of the fuel system (maybe 1 cylinder isn't getting fuel?), but I made sure to check that really well when I put everything back together.
The truck also seems idle at a higher RPM than before, and I've wondered if this is contributing to the shaking problem.
Maybe my torque converter is having problems and sporatically locking/unlocking?
Or is it possible that before, since I had no head gasket, that my compression was horrible, and that now I'm just feeling the extra power/torque that was being lost?
Any help/suggestions would be appreciated.