1995 Trooper 3.2 SOHC 4x4

Mark, pls tell us more about how you used the can of Sea Foam. Did you put it into the crankcase by way of the rocker cover oil entry hole or did you attempt to pour it into the intake manifold? Usually, you add it to the engine oil and then drive the truck a ways to warm it up, then drain the oil and refill. Some folk I know use it by pouring it into the intake - if you did that, and you added too much, you can easily do what you may have done - hydraulically lock a piston. You may also have simply dislodged a piece of carbon and it is now sitting on top of the piston, hitting the head every time the piston goes to TDC. I wouldn't be so quick to pronounce the engine to need a bearing job. If the engine is running well other than a knock, it might be worth while to simply drive it a little while and see what happens. You could also try putting some Marvel Mystery Oil down the intake (in small quantities) in an attempt to dislodge whatever may be on top of the piston, if there is anything there. You could also pull that head, too, and check....

If you in fact did hydraulically lock the engine....The result of that is either bent valves (resulting in a misfiring cylinder) or a bent rod, resulting in a knock (what you may have done). Either way, you're looking at pulling that head, the pan, and that piston/rod combo - you may as well pull the engine and put a set of rings and bearings in it. If you do that, make sure you change out the crankshaft seals at the front and rear of the engine. After 200K miles, they've done their job.

Pls let us know how you used SEA FOAM. r/ Steve

I put the SeaFoam in through the power brake vacuum hose. I've done this before on the Troop and it worked fine but I believe I was too aggressive and/or should have had the motor above idle. I've done this in a number of cars with good success and it cleans the heck out of the chambers.

I knew it was hydralocked, that's why I pulled the plugs to get it to crank.

I also hoped it was a lifter or carbon but pulling the plug wire for #6 made it go away so I knew it had to come apart.

As it turns out I have pulled the pan (that was a fun time) and indeed the #6 rod is visibly bent. The rod bearing looked ok though I have swapped them. I have a used rod and piston on the way from CA.

Tomorrow I will strip it down and remove the head. I thought about pulling the motor but would have to borrow a hoist and I don't have much reason to belive I would gain much from new rings as even newer motors seem to have the consumption issue. I plan to run a hone in #6, have the salvage rod and piston weight matched to the old one, put rings on that one piston and put it back together.

Short history on the truck is it was broken down sitting at a cabin in a mountain community next door to my wifes Uncles cabin. Owner was a friend of the uncle who really wanted the truck gone as the cabin was for sale and they had replaced the Trooper. if the Un cle wanted it he could have it, but he did not think it was worth the parts to get it going.

I put a timing belt, water pump and drive belts on it and drove it 800 miles home. That was this summer and I have been merciless on the truck. Just wish there was a way to add a couple of hundred foot pounds of torque to it.

I've pulled the radiator and will dive into the

Mark, sounds like you have things well in hand. My experience with these is if you do any major work to them, somehow the front or rear seals start leaking, and then you're dripping oil all over. But, as you've said, it's a LOT more work. It kinda sucks when doing this work is self-inflicted, but if your casualty helps someone else to avoid it, then it won't be for a lost cause. Thanks for sharing the process you've been through.

May all your exhaust manifold bolts come loose without breaking, and may your head bolts all come free w/o taking the threads with them. Good luck; let us know how it all turns out! r/ Steve

I pulled it with the exhaust manifold in place and that ought to be a tech tip somewhere as it seems a lot easier that way - you just undo the two nuts holdign the exhaust pipe. I dont intend to remove it at all but for sure it would be a lot easier to get loose off of the truck with an impact wrench. The problem now is I broke a head bolt off so I'm now working to get the remaining ~ 2" of threads removed. I started with an easyout and managed to break that off as well. Nice. Now I have that drilled out but will go tomorrow and get a few cobalt bits to work with the bolt remover kit I borrowed. It is different from the normal reverse thread easy outs in that you drill a hole all the way through and then you beat this fluted deal through it and use a nut type deal to (hopefully) unthread it. Those head bolts were tough.

Do you know if the head bolts and/or the main bolts that hold the oiling manifold to the mains are torque to yield?

In the event the bolt removers don't work do you know if there is a reasonable way to get a heli coil into a head bolt like that?