I have heard about a lot of F-bodys with this serious problem and I was just wondering how common is it and what steps can be taken to avoid it? Besides changing the oil.

My V6 4.3L s10 pickup suffered from this problem twice! Once while the previous owner had it and the motor was replaced under warranty then again about 2 weeks after I bought the car. Both times the motors only had 60k miles on them. Needless to say I am very wary of these GM V6's now but I have aquired a 2.3L Firebird in a trade anyway. Do the SBC's suffer from this as well? I really want to build up a V8 and drop it in.

Also will replacing the bearings as soon as the knicking starts fix the problem? Not something I would do to the 2.3 considering the amount of time/labor.

 

The only way you're gonna spin a bearing or wipe it out is if you run the motor free of oil or have a balance issue. When the rubber binder breaks on balancers, it has a tendancy to wipe bearings. There are other causes too, but those are the big ones.

 

Well the problem is a 4.3 6 is just a chevy 350 missing two cylinders.
It has nothing even in common with the 60* 2.8 3.1 3.4 motors.

60* motors do 200,000+ miles with little maintenance.

 

Now this is something I know something about. If you let the engine run too long with either a bad balance condition or lack of oil ( ) the bearings will spin. If you let the engine run too long without a (one or more) bearing, you run the risk of damaging both the crank and the bearing surface where the bearing was wiped away ( another ). If this condition is not corrected, you run the risk of far worse damage... The best solution is to stop the engine IMMEDIATELY when you hear that familiar sound and have it towed home, where you replace the bearing if any is left, and to correct the condition which caused the bearing to spin (DON'T RUN THE ENGINE UNTIL YOU FIX THE BEARING!). If the bearing surface is enlarged, it can become difficult to find a replacement bearing (if anyone knows where I can find a rod bearing that is oversize in both external and internal diameters, would you let me know?) because I have yet to hear of a company making oversize bearings that are larger in the O.D. direction instead of the crank surface.

(This did not happen to my 2.8 in case anyone is wondering... this was a FWD Chrysler 2.5 I'm referring to... )

Also, DON'T forget to change both the oil filter AND oil pump pickup! The shavings from the bearing like to get sucked into the pickup and gum it up!

 

Thanks guys this thread is very re-assuring! I am now thinking I am going to give the firebird a tune-up and use it as my daily driver. The motor in it only has 106k miles. I think it may be a combination of the 3.1 and 2.8.

My current daily driver is still running but I am sick of it, a 94 Mazda Protege w/ 210k mi. on original engine.

 

Yeah.. just be sure to take care of the engine and it will take care of you...

 

Heat, loss of water, and friction are the engine's major enemies... an engine can run WAY longer w/out oil than w/out water.

A rod knock (wrist-pin failure) and/or spun bearing is a very severe condition that requires quite a bit of additional maintenance/repair.

Change your oil regularly, don't beat the pi$$ out of the engine's RPM band, and make sure that your coolant system is up to par: (big enough radiator, hi-flow water pump, and thermostat heat range - 180* is plenty).

When an engine burns up/rod knocks... it's usually heat-related, which is a 'user error'.
Be aware of the gauges and smells of your engine.