Non-Jeep Tech Help

[brewcoltiii]

OK here goes:
I need some help with a 4.3L V6 in a GMC S15 Jimmy 4WD. The 6's son was driving and the rig died out on him. Once we got it home, found out that the camshaft pulley won't turn at all. Got the pulley pulled, the damper (harmonic balancer?) pulled, took the timing cover off. Tried to get the number 4 to be TDC, but couldn't get it to turn at all. The timing chain looks a little stretched, so that is going to be replaced regardless. A buddy made a took that slips on the end of the camshaft with a nut welded to it so that I can try and turn it. When I took a huge cresent to it to try and turn it, the crankshaft sprocket wiggled a lot! And I'm not exaggerating! I don't have the sprocket puller to get the sprocket off, yet anyway. But if the camshaft is broke, what do I do? That buddy said that if the camshaft is broke, the whole engine needs to be pulled and fixed that way.

I'm lookin for any help available. I know this is not a GMC forum, but I trust what has been said on here and looking for some advice, any advice is helpful.

PM me, reply here, or send some shiznit to my hotmail, [email protected]

[Walldo]

Will the crank turn? What shape is the oil in? How many miles on the motor? Is the motor worth rebuilding? If it was me I would start looking for a good used motor from a salvage yard, or a crate motor from GM, might work out cheaper in the long run. Good Luck

[Navydoc8778]

I had a cam split on an old S10. The fix that made it easiest was: pull motor, replace with crate or j/y engine in decent shape, teach young lad the enjoyment that comes from rebuilding a motor. (much like what was said already). It sucks, it takes a little coin, but it gets the job done. Does he have other transpo, or is this his only ride? If he has other means, don't worry about the j/y motor and just take a couple weekends to build it and stab it back in there.

[brewcoltiii]

Will the crank turn? What shape is the oil in? How many miles on the motor? Is the motor worth rebuilding? If it was me I would start looking for a good used motor from a salvage yard, or a crate motor from GM, might work out cheaper in the long run. Good Luck

I can't turn the crank. The oil looks fine from what I can tell, no metal shavings in it, no discoloration. About 50K on the rebuilt motor. I like the bigger V6 in this rig, but don't know if it worth rebuilding. I'm used to my 4.0 inline on the Jeep. My buddy that made the tool got price quotes from his Napa contract and a timing set is about $60, and a crank set is about $185. I just don't have the exstensive knowledge for the rebuild. But I will definitely keep the crate route in mind.

[brewcoltiii]

I had a cam split on an old S10. The fix that made it easiest was: pull motor, replace with crate or j/y engine in decent shape, teach young lad the enjoyment that comes from rebuilding a motor. (much like what was said already). It sucks, it takes a little coin, but it gets the job done. Does he have other transpo, or is this his only ride? If he has other means, don't worry about the j/y motor and just take a couple weekends to build it and stab it back in there.

He does have other means, but it's a borrowed truck from his girlfriends grandpa. I don't want him to burn a bridge and keep the truck for too long. I would love to teach him the lessons in used rigs, which is pretty much what I'm doing. I will have to have a wrench party soon to help out with this, cuz I couldn't even play a "backyard" mechanic on TV!

[tjsean0308]

what year is it? Was it stumbling at idle before the gave up the goat? I know I have seen quite a few mid to late 90's 4.3ls (the multi port injected not so much with TBI) have problems with the spider injection units. Basically it dumps fuel down the things throat and if the check engine light is busted or ignored or removed, the super rich running condition thins out the oil. I have seen probably 4 or 5 MPI 4.3Ls seize right up from this. I will say that in all the ones I saw it ran like crap and stunk like fuel before it gave up. If it seemed to be running good not stumbling at idle and no CEL could be some other cause.
At the least this is something to look for when shopping for a used engine especially in the J/Ys smell the oil real good for gas if you can see it run, of course thats the way to go.

Sounds like JR gets to learn the ways of an internal combustion engine. I remember my first rebuild..............

[brewcoltiii]

yeah it's definitely become a project. I don't know what the condition of the smell was before it ran. I do remember that it didn't have a rich smell when he bought it. The dummy light was on though. When taking the timing cover and chain off, I tried to make it TDC, the crank sprocket wobbled almost an inch either way. The crank is broke in 3 pieces. I don't know what cause a crank to break like that, but it sure as hell happened.

Our remedy is buying a rebuilt 4.3L with a 90 warranty. and taking the weekend to pull and replace the engines. It is going to cost more for parts and it being down for so long that it really isn't worth rebuilding. of course that is our opinion. Plus I have a guy that wants this one and is willing to pay for it?! I won't rape him for it, mainly cuz he is one of my Soldiers. And he is wanting to get into wheeling. He has been a muscle car nut, and has kinda changed his focus.

I will put more updates when I have them.

[tjsean0308]

Yeah the dummy light on those can be very expensive to ignore, ask me how I found out. I would bet it had the fuel injector module problem starting. Once the oil gets thinned down by gas, they go down hill fast. But its anyones guess as to why it cracked the crank, the ones I have seen mostly just spun bearings and seized up solid. Good luck with the upcoming swap.

[brewcoltiii]

Good luck with the upcoming swap.

its gonna be a joy. I will make sure that the injector module gets checked also. thanks

[brewcoltiii]

Status update on the Jimmy:

I bought a 4.3L carberated, for $400 that came with a 90 day warranty. I have a certified mechanic who is the brother of one of my Squad Leaders going it install it. Cuz I'll be honest, I'm not that smart with mechanical stuff.

Anyway, the total cost for the rig is as follows:
1. $1500 for the rig.
2. $740 for 4 new BFG A/T (mounted, balanced, and they disposed of the old tires) and a muffler installed.
3. $400 for the new engine.
4. ~$350 for labor on the engine swap.
5. Charging the young man for all this plus 5% interest on all borrowed monies; giving the young lad a lesson in what reality is; making the young lad pay for this insurance hike, all priceless!!!!

Just kidding, he is a good kid. He knows what is expected and he will live up to his end of the bargin.