Genuine Volvo V40 Piston

Volvo V40 Piston Parts and Q&A

• Piston
  274399
  Q: What steps should be taken before refitting the piston/connecting rod assemblies on Volvo V40?

  A:

  Before refitting the piston/connecting rod assemblies make sure that the cylinder bores are clean, the top edge of each cylinder is chamfered and that the Crankshaft and intermediate section is in place. Remove big end bearing cap from No 1 cylinder connecting rod and extract original bearing shells, wiping bearing recesses with lint free cloth, keeping them spotless. Have new big end bearing cap retaining bolts on hand. Clean the back of the new upper bearing shell and fit it to No 1 connecting rod and the other shell in big end bearing cap and make sure it is placed in the same position to that of the old shells. Place the Piston Ring gaps in proper position, and lubricate the piston and rings with clean engine oil, and place a piston ring compressor, and leave the piston crown protruding slightly to guide the piston into the cylinder bore. Turn the crankshaft around until No 1 big-end journal is at Bottom Dead Centre and add engine oil to the cylinder walls. Set the No 1 piston/connecting rod assembly in line with the arrow on the piston crown pointing to the timing belt end, ease it into the cylinder bore, and position the ring compressor on the engine block. Tap the top edge of the ring compressor to make sure you have made contact with the block, and then gently tap the piston with a wooden hammer handle and guide the big end of the connecting rod onto the crankpin with a long screwdriver or long-nosed pliers. Maintain pressure on the ring compressor to keep the piston rings from popping out if there is resistance felt. Clean out the bearing surfaces and put a uniform coating of clean engine oil on both, perhaps pushing the piston back a little to expose the bearing surface of the shell in the connecting rod. Slide the connecting rod back onto the big end journal, refit the big end bearing cap, lubricate the bolt threads, fit bolts/nuts and tighten them in stages to correct torque. Repeat this process for the other piston/connecting rod assemblies, being careful not to turn the crankshaft around until the first pair of big end bearing caps has been tightened to their final torque values to prevent dislodging the bearing shells. Key points to remember include, that it is important to keep the backs of the bearing shells and recesses clean, the correct piston/rod assembly for each cylinder and to lubricate cylinder bores and bearing surfaces before fitting the big-end bearing caps. After you have all of the assemblies installed, rotate the crankshaft by hand to see if there is any binding.
• Piston
  274400
  Q: How to remove the piston, oil pump, and flywheel driveplate on Volvo V40?

  A:

  To remove cylinder head, oil pump, flywheel driveplate, begin by removing main sump on the GDI engine or sump and intermediate section on other engines. Check for a heavy wear ridge inside the tops of the bores and eliminate it with a scraper or ridge reamer to avoid jamming of Piston Rings. Make sure each connecting rod and cap has identification marks painted or punched on them if needed to refit them correctly. For non-GDI engines, remove the two connecting rod bolts, tap the cap with a soft hammer, and record the position of the lower bearing shell which has no locating tabs. On GDI engines the bearing caps are held by two nuts and the cap may need to be tapped lightly to release it. Push the connecting rod and the piston out of the bore, which will recover the upper bearing shell, which also has no locating tabs. Refit the cap correctly, so that parts are not mixed up, the serrations on non-GDI engines fit together properly. Check for an arrow on the piston crown which should be pointing to the timing belt end, if not present make a mark in a direction. Without rotating the crankshaft, repeat for the rest of the connecting rods and pistons. Clean the piston/connecting rod assemblies and remove the original piston rings carefully, using old feeler blades so that they do not drop them into grooves. Scrape carbon off the tops of the pistons and grooves of the rings, using an old ring to scrape off deposits without causing damage to the metal. Clean the assemblies using an appropriate solvent and make sure that oil return holes are clear. If the pistons and cylinder bores are not damaged, replace them with the original pistons and replace the rings while reassembling the engine. Inspect each piston for cracks, scoring or burned areas, as well as corrosion that would indicate coolant leaks. Examine connecting rods for damage and make sure they do not bend. To separate pistons and connecting rods, remove one of the circlips and push out the gudgeon pin. Measure piston diameter with a micrometer and compare with specifications; all of these 4 pistons need to be renewed if any are out of tolerance. Measure ring to groove clearance using a feeler blade pay attention to using the correct ring size, and checking gudgeon pin fit for play. Get any new parts required, complete pistons with gudgeon pins and circlips. Oil the gudgeon pin Assembling the connecting rod and piston correctly Reposition the gudgeon pin with the circlip with the opening downwards. Repeat for the rest of the pistons.