What parts are needed to replace piston rings while engine is in the car

remove engine from car , remove engine head , remove oil pan , remove each rod from cylinders

Remove the oil pan and unbolt the connecting rod from the crankshaft on the damaged piston and push it up. It will come out without removing the engine

Bummer. Usually you need to drop the oil pan, pull the rod and piston out, replace the sleeve, and use a ring comprssor to get the piston back into the cylinder and then put it all back together EXACTLY how it came apart including position on the sleeves, rods and bearings. I have not done this on a VW but I do not see this being much different than any other car that I have worked on. No matter what it will be a huge pain in the ***.

1. Rods connects to crankshaft and pistons.
2.Crank access is under car through oil pan removal.
3.Piston is romoved after step 2 through top of engine after cylinder head removal.
4. This is simplified explanation, you need to get head and pan gaskets, a gallon of oil, piston ring compression tool, knowledge of engine components and timing procedures etc...
5. Do you have a big garage and all required tools? What have you fixed on a car before, this is not a beginner or intermediate level fix.

Blue smoke is usually an indication of bad rings, which allows engine oil to be burned as you drive. The fix requires engine teardown, pulling off the heads, removing the oil pan, and removing the crankshaft, rods, and pistons. The cylinders may need to be bored, but at the least they will need cleaned up with a hone. The old rings taken off and new rings istalled. If the engine needed bored, then new pistons must be installed. Then, put it all back together.

Hope this helps you

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

broken/worn piston ring(s). Each piston has 2 rings. These can be replaced by the DIY mechanic by
1) removing head of engine (remove head gasket - you'll replace it), then
2) manually wind the engine (with a ratchet wrench & socket) til the piston in question pops up
3) remove both rings (with ring pliers - available from any auto parts store)
4) install 2 new rings (with a ring installation collar - available at any auto parts store)
--- choose ring installation tool to the correct size for your pistons.
5) re-install head of engine (replacing head gasket)

Note that this procedure preserves the engine timing, so you need not reset it.

First thing you need to do is determine why the compression in that cylinder is low. Four possible causes are 1. blown head gasket 2.bad valve(s) in the head 3. broken compression ring, piston ring land or burned piston. 4. rounded camshaft lobes
One other possibility is a fuel washed cylinder (from leaking injector)
You are going to have to remove that cylinder head and do a thorough internal inspection, possibly involving oil pan and piston removal.
Once the cause has been found you can proceed to make an appropriate repair. Or if the damage is beyond your ability, replace the engine with a used or new one.
There is no quick easy fix to restore compression.

I have toyota corona 3s engine it smokes black and fuel consuption is high we have changed the engine oil and cylinderhead gassecate but still black smoke is comming what should i do