Intakes and Engine Bearings : LUSENET : Countryside II : One Thread

I have a chance to buy a 1993, GMC Jimmy. It has 112k on it, a new tranny. It is a luxury package with Leather seats (a little more than I would look for). The owner wants about 2000 dollars for it. He is tired of it.

Apparently coolant got into the bearings through an intake. I have know idea what this means. My mechanic, who is letting the owner keep it on his lot, was a little busy. He said I could drive it more than the 425 miles that it takes to reach the homestead (where mechanics don't seem so pressed to gouge me), but at some point it could use a new 4.3 V engine. He said it is not worth replacing the bearings, but I think a down home mechanic might disagree.

I'm lost on a few things here. What do the bearings do in the engine. What is the intake involve here, and how could could betray fluid to these bearings.

Thanks for any help.

-- Rick in SW West Virginia (, May 17, 2002


either the intake or the head gasket went out,,, usually by overheating. If your going to replace the bearing,, which is a total tear down of the engine,, you mind as well go ahead and rebuild the thing,,why tear it down again in 15,000 miles. but those engines dont take well to rebuilds,, so the new engine or a junkyard engine would be called for. Something that was wrecked early on in life.

-- Stan (, May 17, 2002.

Or a cracked head or block. If there's so much coolant in the oil that it's turned to a milky sludge, not only the bearings will be shot, but piston rings, possibly scored cylinders, worn valve guides, etc, etc.

If it's that bad, the cheapest best route would be like Stan said, get a good junkyard engine. Plenty of those 4.3 around.

It might do that 500 mile trip ok but I'd have a backup plan in case it doesn't make it all the way.

-- Dave (, May 17, 2002.

I dont think a cracked head/block would make it the 450 miles or so. Thats why I suggested the gaskets. MY back up plan would be downhill,, ALLLL THE WAY,,or a tow truck nearby ,,LOL

-- Stan (, May 17, 2002.

BTW,, a cylinder compression test would help alot in finding out what is wrong with it

-- Stan (, May 17, 2002.

The bearings are what the crank shaft, cam shaft and rod bearing turn on, they provide a surface so that there is not metal to metal contact (though bearings are made out of soft metals), allow for oil lubrication of moving parts. So, if you lose the oil lubricating surface, with say water, then the metal surfaces are normally going to get scorched, bearing turned, etc. All not good things.

Perhaps these newer motors are not worth rebuilding, not sure, know that for some motors, there are low mileage motors available from Japan that are cheaper than rebuilding.

As already stated, replacing the bearings is a complete tear down, so might as well rebuild the whole thing, if you have a good machine shop and excellent mechanic.

-- BC (, May 17, 2002.

Thanks for the thoughts.

A new jasper is 3500, including a 250 rebuild kit. Ouch. I can't afford enough gas to justify that price. The Japanese honda engines are 8 or 900, and my mech told me yesterday the one he put in a car 18 months ago is doing fine.

I would like to rebuild one eventually. It would be quite an endeavor for me though. What is it about rebuilding these 4.3 engines that is harder than others.

I think Mike probably did a compression test. I stopped there at 10 am on Friday, and asked him to feel my Honda Wagon clutch tension for me. He said it was fine (141,000 miles), and even adjusted it for free, even tough he was busy!

Told him I was looking for a 4wd truck, and when I told him I would use it for taking materials up the unbuilt road to our homesite, he told me how this guys kid drove this 93 jimmy, when he should have pulled over.

I asked him if it could make it to the homestead, if I wanted to store it there, and he just looked at me and said " you could probably get away with driving it around for a while". He said it sounds good, he would not lie to me. Mike is a good ole boy, who treats his customers right. He treats me even better- once, when the dealer wouln't help me loosen the bolts I could not budge, he removed and replaced my lifetime muffer for me for free (I had to tip his technician 10 bucks)

Mike knows that I bought a 2nd civic, knowing it used oil, and have squerezed 5000 miles from it, and I think this engine has a few thousand miles left in it, or he would tell me to just replace it.

-- Rick in SW West Virginia (, May 18, 2002.

those 4.3 are pretty solid motors. I've never rebuilt one but have rebuilt a few of those generation GM engines. As long as it's prepped good, blueprinted, etc you should be fine. If it's scored up bad, you have to rebore the cylinders, buy new oversised pistons, regrind the crank, oversize bearings, etc, etc. That's where you start running into the cost not being worth it. The thing is on something like that, it's probably not worth putting the money in and much easier to just get a low-mileage junkyard engine.

If it's not that bad, I'd just fix the coolant leak, flush the oil out real good and drive as is. If it only has a little bearing knock, using thicker oil like 20/50 and/or adding 2 pints of STP additive might squeeze a bit more life out of it.

Diesel or mineral spirits works good for flushing but you have to be real careful or you'll burn your bearings up even more. Get the engine up to operating temperature, drain the oil, put a new filter(cheapest you can find) on, fill with 1 quart oil, the rest diesel or mineral spirits. You do NOT want to let the engine run more than a second or two, just long enough to pump the mineral spirits through it. Let it sit, run a few more seconds, let it sit, repeat 5 or 6 times. Drain it out good, put fresh oil/filter in, change it in about 500 miles. Don't forget to clean out pcv valve, oil breathers, etc.

-- Dave (, May 18, 2002.

It is much more cost effective to replace the engines now. Our countryboy mechanics quit rebuilding them when factory spec rebuilt crated engines dropped to $1400 guaranteed. Why spend a grand on a rebuild kit and machine shop work, when for the same costs, you can have "factory fresh" ? Most mechanics also cut a labor deal to you on a crated engine swap as its less messy.

-- Jay Blair in N. AL (, May 18, 2002.

Rick, when you get the new engine in, isn't there going to be other things that have to be replaced too? ( Like the clutch?). I have an 88 Toyota 4 cylinder. I use it for my emergency back-up, the engine has had a little knock for a couple of years, but since I don't use it often, I'm just waiting till it blows.

*I* wouldn't have another 4WD with only 4cyl. I think the 6 cylinders offer so much more oomph for the buck.

When I leave Lexington heading across the mountains on 64, even the heaviest loaded 18 wheelers leave me in the dust as I putt-putt-putt over the taller peaks. I don't take that 4cyl. anywhere there are hills anymore. LOL! ! !

Seriously, you'll have 4000 dollars in that vehicle before you bat an eye - - and if you watch carefully, bet you can get better for the bucks. I'm always suspicious when someone keeps a vehicle for 9 years, than they are "tired" of it.

Do you like auctions? Ever heard of the Lancaster Farming paper? There are so many estate auctions EVERY week, within an easy drive of you. Baltimore Sun has some too, as does the Frederick paper. I've seen some really good vehicles go for good prices at the Estate auctions of "senior" farmers.

One of my mother's wise admonitions >>> Buy a bargain, get a bargain.

-- Granny Hen (Cluckin, May 18, 2002.


I will try the diesel cleaning depending on how bad it seems. I may have to try it on Little Blackie our civic hatchback soon. She seems to be using a quart every 500 miles now.

Sounds like the only way to see if the engine could be rebuilt for around the same 1000 to 1500 is to pull it, take it apart and check it out. We could do that- we have time on our side, as we are one year at minimum from needing it regularly as we have not moved!

Granny, My 4 cyl hondas are 5 speeds and with downshifting between 60 and 65, I can keep ahead of half of the trucks

It should be let's say 1400 for an engine, and I have a friend down home who has replaced engines before. He is only 20, but has kept cars running for his mom since she bought him his first Chilton's. Fortunately, I have been able to do a few good turns for my friends, and my cost for labor can probably be as low as buying dinners for the week.! (I gave them a 91 topaz my mom was tired of. That 420 drive with auto and criuise control was almost fun!)

The clutch should not need replacing, that should have been covered by the new tranny. I think 3000 to 3500 is doable. The truck will have new engine and new tranny then, and new anything else I can find. If he wants more that 2000 for it I'm not interested.

I have connsidered trying to find one in an estate, just haven't taken the time.

Thanks for the thoughts.

-- Rick in SW West Virginia (, May 18, 2002.

you lost me on the 4cyl talk. The 4.3 is a v6. Pretty good torque and hp for a 6 too.

If it just needs a basic rebuild- bearings, rings, gaskets, that'd only cost you a few $100 at most if you did it yourself. Even a crank regrind and block prep wouldn't be much more.

Speaking of auctions in that region, there's also the big mason-dixon auto auction up in Greencastle, PA. They have a website at

The Lancaster Farming paper is quite a read. I haven't seen that for a long time.

You're in the Lexington area Granny Hen? That's a real pretty part of the country. I hung out a few months around Waynesboro and another 3 months near Goshen living in a tent while working for the Boy Scout camp there. Then I wandered down to Martinsville and stayed almost 2 years and that was the extent of my VA citizenship.

-- Dave (, May 19, 2002.


I'd love to rebuild a 4.3. I've never even attempted a lawn mower, but I'm sure Matt would get a charge out of doing it, and I'd love to get the experience.

-- Rick in SW West Virginia (, May 19, 2002.

Yup Rick, get a good guide and it doesn't require any special skills. I prefer the factory manuals myself but they're not cheap. Unless you can find one used on Ebay or somewhere. I think the last one from GM cost me around $50. The much cheaper Chilton or Haynes manuals tell you enough to do the job without complicating things. You don't need a fancy torque wrench, a cheap beam type is good enough. Get some plastiguage for a few dollars to check tolerances and other than that no real special tools needed. Just keep things in order and organized when you tear it down, number all the pieces so they go back in the same order. If you're just putting in rings, bearings, and gaskets it won't take long. A decent machine shop will take your stripped down block, cook it out(clean out the gunk), and install your cam bearings for $50-75 or so(that'd take a special tool to do yourself). Then it's just a matter of putting it back together. Just remember to prime the oil pump before you start it up.

-- Dave (, May 19, 2002.

Ok on the 4.3 its a good motor This is my imput being a truck and heavy equip mechanic!!If u put rods and main bearings in you my as well put rings in and do the heads!! u will spend about 5to 7 hundred on parts to rebuild urs if you block and crank are good U can get a new Gm Crate motor for about 1800 most charg about 3 to 5 hundred to put it in a used motor about 3 to 5 hundred plus instalation!!being a 93 with the milleage u got on it id put in a used motor if u try and take it over those mountains on 68 u will break down if u patch it if u need a source for a used motor email me ok

-- Grizz At home 4 awhile!! (, May 19, 2002.

You don't say whether this is a 4wd or not. This would be a big factor in the value of this vehicle. A 4.3L V6 in a GM truck is just like the 8 cyl. engine with 2 cyls cut off. The eighth digit of the VIN will tell you exactly which engine you have. There are 2 versions one is a Z and one is a W. The Z uses throttle body fuel injection and is a good economical easy to repair fuel system. The W is a good system but not vey economical to repair. It uses a central injector which is expensive and does go bad. Chances are the intake gasket leaked for quite a long time for enough coolant to get into the oil to damage the bearings. This is a sign that the previous owner probably wasn't very maintenance councious. This truck might sound like a deal but you could end up dropping a lot more into it than you want to. The best way to economically fix this truck would be with a "good" used engine purchased from a reputable salvage yard and possibly one you could hear run. If you plan on keeping this for any time then you might consider a remanufactured or new engine with a warranty. From experience I will tell you that a cheaper rebuilt engine is just that. You get what you pay for. As far as rebuilding it yourself with you providing all the labor you'd be lucky to do it right for $700- 900. I'm not saying it can't be done cheaper, but a job worth doing is a job worth doing right.

-- Emil in TN (, May 21, 2002.

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