I'm looking for suggestions as I rebuild my 1996 4.0. I have a rod knocking so it will be a complete teardown. As long as it's all apart I'm thinking about camming it and replacing the injectors. My goal is better gas mileage and reliability, not speed. Anybody have this problem in the past and if so are you happy with the results? Please pass along your expertise. Thanks.

 

I'm in kind of a simular situation as you but I can not tell you much other than I felt it was more expensive to rebuild than it should have been. My motor was in very good condition to begin with but still needed to be bored, which required new pistions/rings, had the block and head cleaned, had a mild valve job done and head rebuilt using old parts, replacing the cam, new bearings, gaskets, oil pump, and I'm well into the $1500 range and I still have to assemble it myself.

I thought about putting a "better" cam in but that then required new springs and rockers which would have added to the cost, and since I was already spending more than I planned I oppted to just use the stock cam. I'm going to try some "bolt-on" parts to help performance, but I am prepared that I won't get much better gas mileage.

With a bad rod know I would think you might need to have the crank worked and maybe replace rods too. So how much it too much? Is the vehicle in good enough condition to warrent spending half (or more) of it's value in just the engine?

 

I just rebuilt my 88 4.0 and it cost me $1,200.00 That was a complete valve job, Block cleaned, new cam bearings, and freeze plugs installed, crank turned, cylinder bored, new pistons,bearings, cam, lifters, timing set, and gaskets. I also had to replace the oil pan and clutch but even with that I still came in under $1,500.00 with new fluids.

 

Thanks for the tips. This one is worth spending the money on as it's all tricked out just the way I want it: 3.5 lift, warn winch, dual batteries, isolater, onboard compressor, 31" BFG's, roof rack, front disconnects, rear lockers, detachable face cd/cb radio and more, all on a rust free south western body.

 

I am in the process now of rebuilding the engine in my 1992 Laredo. I bought a block and crank off of CL and had that machined. I upgraded my rebuild kit to hypereutectic pistons with a teflon skirt, and ordered new 4 hole injectors. I am still below $1500 even buying the block, crank and injectors. Going to use the block that im taking out to build a stroker over the next yr or so. The rebuild kit i found online cost me $535 and I bought a set of reconditioned rods.

 

Thanks for the advice Cherokee40. I will look into your suggestions.