Genuine BMW 330i Piston Ring

BMW 330i Piston Ring Parts Questions & Experts Answers

• Piston Rings Repair Kit
  11257559434
  Q:

  How to remove and install Piston ring and piston/connecting rod assemblies on BMW 330i?

  Posted by Siqi L.

  A:

  Before removing the piston/connecting rod assemblies, check for rings at the maximum travel limit of the ring and remove those rings when necessary. Flip on the engine so that its Crankshaft faces upwards. Use feeler gauges to check the connecting rod endplay and get a service limit from an automotive machine shop. Find out whether identification marks are present on the connecting rods and caps then mark them if they are not available. Loosen all connecting rod cap bolts and remove each cap and bearing insert. Drive each connecting rod/piston assembly through the top of the engine. Repeat this process for other cylinders too. Reassemble the connecting rod caps and bearing inserts in their respective connecting rods after removal. Check these new piston rings before they are installed to make sure their ends meet, adjusting them as required otherwise. Proceed to put rings onto pistons according to correct order only; then install pistons/rods assemblies after cleaning cylinder walls with chamfered upper edge in each bore and ensuring that a crankshaft is in place. Clean up bearing surfaces of both connecting rod big-end bore/cap and fit new upper bearing insert thereon. Lower bearing insert should be fitted into rod cap while making sure that piston ring gaps were located 120 degrees apart around its perimeter for proper positioning on piston top assembly along with lubricating it using clean engine oil before compressing them by inserting suitable piston ring compressor over until such point when all projections have been pressed down with enough force just like back into cylinder block holes provided by manufacturer themselves requiring rotation of crankshaft then later applying oil on cylinder walls followed by gentle installation of piston/rod assembly right inside cylinder bore guiding connection rods towards journal part of crankshaft itself ending up with checking connection bearings oil clearance applied Plastigage to be removed afterward in case it was not within range: keep supporting elements clear off any dust or contaminants since it has been already greased either way slid again onto initial position over journal, put rod back then tight those nuts repeated rest cylinders as well turning crank test binding on play.

  Answered by BMW Parts Specialist Brad / May 29, 2025