Thread: Engine problem

Sounds like it's junk.

If it spun a bearing and you have metal flakes in the oil you are better off just getting a different motor. It is not cost effective you rebuild a 3800 with how much machine shop work is required. Also if the crank is damaged from a spun main or rod bearing, it's going to cost even more.

Bearing failures are fairly common, between that and intake gasket failure. Like 7-8 years ago with my first 97 GTP, I took a 90 mile road trip to our cabin and the rod knock started as I pulled into the driveway. Happened out of the blue and that was that for that motor/car.

Find a used motor; yank it apart minus the short block...re-gasket everything, but if your top end is good; just re-use that. Pretty easy to work on these things too. Only thing you really have to worry about on a bone stock car is the downpipe bolts snapping since it's so old, and the b1tch bolt that's goes into the bell housing backwards under the rear manifold. You can get it with like 5,765 feet of extension thru the passenger wheel well. There is also a goofy transmission brace on the passenger side as well that bolts the engine and trans together.

Can be done with simple hand tools, and an engine hoist. Just un-bolt the hood, remove the dog bones, and you'll have all the room/movement you'll need.

I'd also replace things like the motor/trans mounts, have the cylinder heads gone through at a machine shop, have the lower intake hot tanked...and if you want, I'd reseal the supercharger with new anerobic sealant, put a new coupler/fluid in there and scrub out the throttle body as well. You'll basically have a brand new engine top to bottom with used parts.

Don't even open up the used motor. If you remove any rod bearing cap or main bearing cap it has to go to a machine shop. It's not like an old 350 or small block ford, these engines like twist when something is removed.

Un related to your issue specifically, I had a 2000 n/a GP that ran like a top. Never a lick of trouble. Then one day right as I let off the gas, to go down an off ramp, It stumbled and would barely idle. I figured it was a bad sensor or something else not very serious, so I limped it home. Turns out it broke an intake valve spring, letting the valve drop and bounce off the piston about 60,000 times. Fluke thing... just let go....

Now that I think of it; Idaho is far...but if you strike out on engines I have a fully studded and balanced rotating assembly I had built a few years back for a huge turbo car that I never used. I could take out the head studs and you could literally put all the stock parts on it. The rest of the car should fall apart before that motor would quit working LOL. L32 pistons and rods (from the '04+ GTP's), ARP Main Studs, brand new bearings throughout. Block has been decked for a little more compression but not enough to affect anything on a stock car. I'd always suggest putting a downpipe in there though while the engine is out if you plan on keeping it. It's the most restrictive part of the car. ZZPerformance sells a nice bolt in catted or catless unit that hooks up right to the stock catback.

Give 'em Hell.

you'l need to start shopping around for whats out there local to you, then make up your mind as to a top swap or not.

top swap, or a bottom swap in your case as well as mine, you just use the short block of a na 3800. bolt on the balancer, heads lim and blower from the old engine on it.

no idea what that is.

all your doing is using a higher compression bottom end. headers should be installed as well to help let it breath better. stock tune from your gtp should work fine, or get a tune to get the most out of it.

dont check anything in the bottom end if you want it to run still. open them bearing caps and its junk. re gasket it all but the heads install new rear main seal and rear cover gasket, clean and paint it nice if you care to.

It's not about being TTY or any of that stuff.

There are three basic reasons for line boring the main bearing and cam bearing bores in engine blocks. One is to restore worn, out-of-round or damaged bores. If an engine overheats or loses oil pressure, one or more bearings on the crankshaft or camshaft may seize and spin. The resulting damage to the bearing bore must then be repaired by either machining the hole to accept a standard sized bearing or an oversized bearing.
With main bearings, a worn, out-of-round or damaged bore can be restored back to standard ID by grinding or milling the mounting surface of the main caps, bolting the caps back on the block, and then cutting the holes back to their original dimensions.
In the case of worn, out-of-round or damaged cam bearings in an engine block, there are no removable caps. The only option is to enlarge the bores so new oversize cam bearings with a larger outside diameter (OD) can be installed.
Reason number two for line boring a block is to restore proper bore alignment – a process which is often called "align" boring (or honing if a line hone is used instead of a boring bar). As rigid as an engine block might seem, there is actually quite a bit of residual stress in most castings. As a new "green" block ages and undergoes repeated thermal cycles, the residual stresses left over from the original casting process tend to distort and warp the engine. This affects the alignment of the crankshaft and camshaft bores as well as cylinders. Eventually things settle down and the block becomes more or less stable (a "seasoned" block). The bearings as well as the crankshaft and camshaft journals gradually develop wear patterns that compensate for the distortion that has taken place.
Additional warpage can occur if the engine is subjected to extreme stress (like racing) or overheats. If the original crankshaft or camshaft is then replaced without align boring the block, it may bind or cause rapid bearing wear. Likewise, if you’re building a high performance engine with close tolerances, you don’t want any misalignment in the main bores or cam bores.
The third reason for line boring or honing a block is to correct or change bore centers or bore alignment (as when "blueprinting" a high performance engine). The camshaft and crankshaft should be parallel in the block. If they are not, line boring can correct the misalignment to restore the proper geometry. With performance engines, there may also be a reason to change the centerline of the crankshaft or camshaft slightly to alter the piston or valvetrain geometry.

This is really why, once the caps are removed you are now in a way ruining what was once a properly aligned motor.

Originally Posted by Fivefingerdeathpunch

It's not about being TTY or any of that stuff.
There are three basic reasons for line boring the main bearing and cam bearing bores in engine blocks. One is to restore worn, out-of-round or damaged bores. If an engine overheats or loses oil pressure, one or more bearings on the crankshaft or camshaft may seize and spin. The resulting damage to the bearing bore must then be repaired by either machining the hole to accept a standard sized bearing or an oversized bearing.
With main bearings, a worn, out-of-round or damaged bore can be restored back to standard ID by grinding or milling the mounting surface of the main caps, bolting the caps back on the block, and then cutting the holes back to their original dimensions.
In the case of worn, out-of-round or damaged cam bearings in an engine block, there are no removable caps. The only option is to enlarge the bores so new oversize cam bearings with a larger outside diameter (OD) can be installed.
Reason number two for line boring a block is to restore proper bore alignment – a process which is often called "align" boring (or honing if a line hone is used instead of a boring bar). As rigid as an engine block might seem, there is actually quite a bit of residual stress in most castings. As a new "green" block ages and undergoes repeated thermal cycles, the residual stresses left over from the original casting process tend to distort and warp the engine. This affects the alignment of the crankshaft and camshaft bores as well as cylinders. Eventually things settle down and the block becomes more or less stable (a "seasoned" block). The bearings as well as the crankshaft and camshaft journals gradually develop wear patterns that compensate for the distortion that has taken place.
Additional warpage can occur if the engine is subjected to extreme stress (like racing) or overheats. If the original crankshaft or camshaft is then replaced without align boring the block, it may bind or cause rapid bearing wear. Likewise, if you’re building a high performance engine with close tolerances, you don’t want any misalignment in the main bores or cam bores.
The third reason for line boring or honing a block is to correct or change bore centers or bore alignment (as when "blueprinting" a high performance engine). The camshaft and crankshaft should be parallel in the block. If they are not, line boring can correct the misalignment to restore the proper geometry. With performance engines, there may also be a reason to change the centerline of the crankshaft or camshaft slightly to alter the piston or valvetrain geometry.


This is really why, once the caps are removed you are now in a way ruining what was once a properly aligned motor.

The way I read that is that line boring is required and bearing bores need aligned before bearing shells are installed into an engine that has had distress...
Please explain, what does this have to do with removing and reinstalling bearing caps in an engine without distress as along as you follow the correct procedures for installing the caps such as torque procedure. The information quoted above doesn't explain why removing and reinstalling a cap would cause misaligned engine bearing bores. Caps are specific to the block/rods they are mated with and machined together. It only says line boring should be done for replacement work or rebuild work which I agree with. But simple replacement or inspection of bearings and nothing else I am not convinced is wrong or risky to the life of the engine.

Don't get me wrong here, I do not want to harm my engine. I want it to last as long as possible trouble free. I think it would be stupid not to look at a couple of bearings and decide if its worth installing in the car without new bearings. Please explain further why a 3800 is different than any other motor. I have done this same thing with other engines and had zero problems. Are there any reputable references that you guys know about regarding this?