How do I change a piston rod on a pontiac grandam? Can I gfo through the bottom if I remove the oil pan, or do I need to go through the top?

you have to remove engine from vechicle .drain oil out.you have to remove cylinder heads and tilt engine around on engine stand you have to remove oil pan then remove rod bearings caps bolts remove cap.put piece rubber hose on rod studs protect crankshaft. then you tap piston using piece of wood tap piston from bottom worn it out from top of cylinder head.

Fluid level and a dirty filter are the first things to check, then a band adjustment is next on the list. as the pan needs to come off to change the filter adjst the bands at the same time. the tea levels in the bottom of the oil pan will tell you in there are more serious issues inside.

Terry

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Remove or disconnect the following:

1. Transaxle/flywheel;Front cover'
2. Timing chain;
3. Oil pan;
4. Oil pump pipe and screen assembly; and
   
5. Connecting rod cap and push piston and connecting rod assembly to the top of the cylinder.

Replace the bearing and reassemble by reversing the process/

this is a bottom end problem - you could have a spun rod bearing cracked a piston skirt you will have to remove the engine and pull the oil pan and check the rods

remove engine from car and install on an engine stand, remove head and oil pan, disconnect lowe rod bearing cap and remove piston through the top, measure crank with a micrometer to get proper bearing size, install rod onto piston and install using ring compressor then install on crank shaft, lube well, reassemble engine and install in car

i think you need to take the oil pan back off and take a good look at the rod bearings, this engine sounds a lot like upper end noise when the piston is hitting the bottom of the cylinder head because a rod bearing has spun.

This is for a 3.3L motor
Hope this helps, it it does please leave feedback and vote Thank You and Good Luck

REMOVAL

1. Release hood latch and open hood.

Removal/Installation of Battery Cables

1. Disconnect battery negative cable.
2. Remove windshield wiper housing, refer to the Windshield Wipers and Washers for proper procedures.
3. Remove accessory drive belt.

Generator Mounting Bracket

1. Remove bolt holding top of generator mount bracket to engine air intake plenum.
2. Remove bolts holding outside of generator mount bracket to generator mount plate.
3. Remove bolt holding top of generator to mount bracket.
4. Remove generator mount bracket from vehicle.
5. Rotate generator toward rear dash panel.

Generator

1. Disconnect the push-in field wire connector . from back of generator.
2. Remove nut holding B+ wire terminal to back of generator.
3. Separate B+ terminal from generator.

Generator Pivot Bolt

1. Remove bolt holding bottom of generator to lower pivot bracket.

Generator

1. Remove generator from vehicle

INSTALLATION

1. Place generator in position on vehicle.
2. Install bolt to hold bottom of generator to lower pivot bracket.
3. Place B+ terminal in position on generator.
4. Install nut to hold B+ wire terminal to back of generator.
5. Connect the push-in field wire connector into back of generator.
6. Rotate generator forward away from dash panel.
7. Place generator mount bracket in position on vehicle.
8. Install bolt to hold top of generator to mount bracket.
9. Install bolts to hold outside of generator mount bracket to generator mount plate.
10. Install bolt to hold top of generator mount bracket to engine air intake plenum.
11. Install accessory drive belt.
12. Install windshield wiper housing, refer to the Windshield Wipers and Washers for proper procedures.
13. Connect battery negative cable.
14. Verify generator charge rate.

First you have to locate the source of the noise. Use a long screw drive putting the hold on your ear and the tip on the different engine spots. A needle stethoscope can do the job better. If the noise is coming from the bottom of engine, and amplified during acceleration, then you may have a crank shaft problem, this is bad news and need engine rebuild. The overhead cam noise is a tick. Might be a collapsed lifter or more. Hope this will help.

There are several reasons why you would hear a loud knock from the engine, and the knock will usually be either in the top end or in the lower or bottom end of the engine.

The first thing that should be done is to drain the engine oil, and then pour the oil filter into a pan where you can see it, and if there is a lot of metal flakes, or a fine cloud of brass floating in the engine oil, you will not want to waste the time or the money trying to repair that engine by dropping the oil pan and replacing the piston rod bearings, it will only be a very temporary patch at best, that is if the patch even lasts for a day.

If you do find metal flakes in the engine oil and oil filter, the piston rod bearings will not be the only bearings in the engine that will need to be replaced, and the crankshaft main bearings can only be replaced by removing the engine and placing it upside-down on a good engine stand. The biggest problem would be that even if you did successfully replace the piston rod and crankshaft main bearings, it would only take one piece of metal flake that was left over in the engine block to find its way to one of your new bearings and then it will take no time at all before that engine will be right back where you started, and that is how important just the cleaning process is in repairing or replacing internal engine components.

If you do not find any metal in the engine oil or oil filter, then you should attempt to find the actual cause of the knock before you decide how to repair the engine, and you will have to remove the engine oil pan to inspect the rod bearings, and if you do remove the engine oil pan make sure that when you inspect the rod bearings that you only do so one at a time because you can not mix up the rod caps, and be very sure that when you remove a rod cap that you do replace it the same way that it came off, and if you turn around the rod cap and install it the wrong way or scratch the crankshaft bearing surface the rod bearing will fail.

If you can hear the knocking louder from under the vehicle then the most likely causes for a lower end engine knock are a damaged piston, worn out piston rod bearings, a broken piston rod, a broken flex-plate, and sometimes loose torque converter to flex-plate bolts, and the only parts that you can really check out without opening up the engine would be a broken flex-plate, or for any loose torque converter to flex-plate bolts.

If you can hear the knocking more from the top of the engine, then the most likely causes for an upper engine knock would be a faulty lifter, or broken rocker arm, or a broken valve spring allowing the valve to contact the piston, and it will require the removal of the valve covers and possibly the intake manifold to inspect for the problem.

If you have any doubts then it would be a good idea to consider a good used engine that you can hear run before you buy it, or a rebuilt engine for that vehicle.

I hope that this information will help you out and save you some time and a lot of money.

These procedures may be performed with the engine in the car. If additional overhaul work is to be performed, it will be easier if the engine is removed and mounted on an engine stand. Most stands allow the block to be rotated, giving easy access to both the top and bottom. These procedures require certain hand tools which may not be in your tool box. A cylinder ridge reamer, a numbered punch set, piston ring expander, snapring tools and piston installation tool (ring compressor) are all necessary for correct piston and rod repair. These tools are commonly available from retail tool suppliers; you may be able to rent them from larger automotive supply houses.

• Remove the cylinder head.Elevate and safely support the vehicle on jackstands.
  

• Drain the engine oil.
  Remove any splash shield or rock guards which are in the way and remove the oil pan.
  Using a numbered punch set, mark the cylinder number on each piston rod and bearing cap. Do this BEFORE loosening any bolts.
  Loosen and remove the rod cap nuts and the rod caps. It will probably be necessary to tap the caps loose; do so with a small plastic mallet or other soft-faced tool. Keep the bearing insert with the cap when it is removed.
  Use short pieces of hose to cover the bolt threads; this protects the bolt, the crankshaft and the cylinder walls during removal.
  One piston will be at the lowest point in its cylinder. Cover the top of this piston with a rag. Examine the top area of the cylinder with your fingers, looking for a noticeable ridge around the cylinder. If any ridge is felt, it must be carefully removed by using the ridge reamer. Work with extreme care to avoid cutting too deeply.When the ridge is removed, carefully remove the rag and ALL the shavings from the cylinder. No metal cuttings may remain in the cylinder or the wall will be damaged when the piston is removed. A small magnet or an oil soaked rag can be helpful in removing the fine shavings.
  After the cylinder is de-ridged, squirt a liberal coating of engine oil onto the cylinder walls until evenly coated. Carefully push the piston and rod assembly upwards from the bottom by using a wooden hammer handle on the bottom of the connecting rod.
  The next lowest piston should be gently pushed downwards from above. This will cause the crankshaft to turn and relocate the other pistons as well. When the piston is in its lowest position, repeat the steps used for the first piston. Repeat the procedure for each of the remaining pistons.
  When all the pistons are removed, clean the block and cylinder walls thoroughly with solvent.