94 Sable, Connecting Rod noise

[Alpha One]

My 94 Sable is making a clanking noise for the past few months. A mechanic told me it was a worn bearing at one of the connecting rods. He also said that I would probably be better off buying another car because this repair is expensive. How long may it last? I know a bearing could go making noise for months even years.

In the manual, it says a connecting rod or its bearing can be replaced by removing the cylinder heat and oil pan with the engine in place. I have done it before on a smaller car, the cylinder head only. In this case, would this repair be difficult? If the car could make it for a few more months and I decided to do the repair myself, I would wait for the Spring when it is warmer.

Thank you

Antonio

[KimMG]

Allowing the rod to rattle around can cause damage to the crank shaft and rod. It may even break loose and go through the side of the block. If you are going to continue to drive the car in this condition, use a motor oil like 20-50 or thicker.

Jack up the car and place jack stands for support. Put a big piece of cardboard under the motor (this will make it easier for you to move under the car, a poor man's creeper). Using a shop light, take a look at what's involved with removing the pan.

You may be able to replace the bearing without removing the head. After removing the oil pan, remove the spark plugs, hand turn the crank until the problem rod is at bottom dead center. This may allow you to push the piston up enough to replace the bearing.

If I had to go to the trouble of removing the head(s), I would pull the motor and rebuild it.

For a cheap fix, I would look for a good used engine or short block and spend a weekend changing the motor. A rear-end wreck or a bad transmission can send these older cars to a wrecking yard with a good motor.

[Alpha One]

I removed the oil pan and removed the six rod bearings. The one for cylinder #1 was bad. The crankshaft was already oval. I replaced all bearings with new ones. The #1 has a bigger gap one direction than the other and of course the oil gap is too big in than direction. I can ear a little click, about as loud as when I first noticed it a few months ago, maybe less but it’s there. The oil light doesn’t flash anymore.

Before it gets that bad again, can I disconnect the spark plug and injector so that cylinder #1 doesn’t fire and maybe the engine will last longer until I replace the engine. It’s cold to replace it now.

The engine will shake a bit. Will that ruin the engine quickly? What if I disconnect two cylinders so that the engine will be more balanced? Less power but who cares.

Thank you

[KimMG]

Disconnecting the spark plug will not stop the crank shaft from turning. You have a bad crank shaft.
Sorry, but there is no temporary fix. You are going to have to decide what your repair goals are. If you are replacing the motor, then anymore damage won't matter. If you are going to rebuild, be aware that the #1 rod can still break loose and cause major damage to the block.
I would go with engine replacement since a major part (crank shaft) is damaged.
Do you have a garage? If yes, and it is safe to do so, use a space heater to warm it up. An engine swap shouldn't take more than a couple of days. If you have a digital camera take lots of pictures. They'll help with reassembly.

[willpower101]

Originally Posted by KimMG

Disconnecting the spark plug will not stop the crank shaft from turning. You have a bad crank shaft.
Sorry, but there is no temporary fix. You are going to have to decide what your repair goals are. If you are replacing the motor, then anymore damage won't matter. If you are going to rebuild, be aware that the #1 rod can still break loose and cause major damage to the block.
I would go with engine replacement since a major part (crank shaft) is damaged.
Do you have a garage? If yes, and it is safe to do so, use a space heater to warm it up. An engine swap shouldn't take more than a couple of days. If you have a digital camera take lots of pictures. They'll help with reassembly.

dude, you already opened it up once. just jack it up and replace the crank this time.