Reply to thread

Message

<blockquote data-quote="JamesBe" data-source="post: 2399893" data-attributes="member: 660463"><p>If youve got an oil fouled spark plug the engine is no good. One question: I thought a SIERRA was a full size half ton truck (1500). Was this four cylinder in the truck when you got it? Cause ive never seen that motor in a full size. Anyway, if it burned up the rod bearings you need to change the main bearings too, sicne you have to tear it down that far anyway. The bearings wont cost that much. But be sure to check your main caps/journals as a spun main bearing will cause wear here and cause a clearance issue with your crank, negating all your work. Plastigage is a great thing. But someting to think about: A black spark plug could be carbon fouled (incomplete combustion) due to various problems with the injection or ignition system, but only if its dry. If the plug is wet/black with oil youve got a punched piston or REALLY bad rings. So make sure, but it sounds like youve got a pretty good handle on it already as you know enough to diagnose a rod bearing problem. But seized mains will cause engine lockup too, and would kill your crankshaft. Or cam bearings. Gotta check it all in this situation. If it were me I would get another motor, maybe another 2.5, but 350&#039;s are cheap too if you get them from the right place. Many salvage yards stock engines that are still good. It may be cheaper than buying a full rebuild kit and rbuilding that 4 banger youve got. You would probably get better fuel mileage and engine life too as a bigger engine wouldnt have to work as hard to move your full size truck. If im wrong and you have a GMC sonoma (S10) you can still buy another motor, but the biggest you could swap in without custom fab work would be a 4.2 V6. ood luck and hope this helps.</p></blockquote><p></p>

[QUOTE="JamesBe, post: 2399893, member: 660463"] If youve got an oil fouled spark plug the engine is no good. One question: I thought a SIERRA was a full size half ton truck (1500). Was this four cylinder in the truck when you got it? Cause ive never seen that motor in a full size. Anyway, if it burned up the rod bearings you need to change the main bearings too, sicne you have to tear it down that far anyway. The bearings wont cost that much. But be sure to check your main caps/journals as a spun main bearing will cause wear here and cause a clearance issue with your crank, negating all your work. Plastigage is a great thing. But someting to think about: A black spark plug could be carbon fouled (incomplete combustion) due to various problems with the injection or ignition system, but only if its dry. If the plug is wet/black with oil youve got a punched piston or REALLY bad rings. So make sure, but it sounds like youve got a pretty good handle on it already as you know enough to diagnose a rod bearing problem. But seized mains will cause engine lockup too, and would kill your crankshaft. Or cam bearings. Gotta check it all in this situation. If it were me I would get another motor, maybe another 2.5, but 350's are cheap too if you get them from the right place. Many salvage yards stock engines that are still good. It may be cheaper than buying a full rebuild kit and rbuilding that 4 banger youve got. You would probably get better fuel mileage and engine life too as a bigger engine wouldnt have to work as hard to move your full size truck. If im wrong and you have a GMC sonoma (S10) you can still buy another motor, but the biggest you could swap in without custom fab work would be a 4.2 V6. ood luck and hope this helps. [/QUOTE]

Name

Verification

Loading…