Overview - Piston And Connecting Rod
WARNING: This page is about a different car, the 2016 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Lubricate all bearings and running surfaces.
Oil injector jet for piston cooling. .
- Bolts
- 35 Nm + 90°
- Always replace
- Use old bolts to measure radial play.
- Lubricate the thread and contact surface.
- Connecting Rod Bearing Cap
- Due to the separation procedure (cracking) of the connecting rod, the connecting rod bearing cap only fits in one position and only to the corresponding connecting rod.
- Mark for installation later
- Mark allocation to the cylinder with paint -B-. .
- Note when installing: the wide thrust flange -A- must point to the same side on connecting rod and connecting rod bearing cap
- Bearing Shells
- Note the installation position
- Replace any worn bearing shells
- Note the version: the upper bearing shell (to the piston) is made of wear-resistant material. Refer to Parts information
- Make sure the retaining tabs are secure.
- Connecting Rod
- Always replace as a set.
- With a cracked connecting rod bearing cap
- Mark allocation to the cylinder with paint -B-. .
- Axial play for each new connecting rod pair: 0.20 to 0.44 mm
- Radial play, measuring. Refer to CONNECTING RODS, CHECKING RADIAL CLEARANCE .
- Installed position.
- Note when installing: the wide thrust flange -A- must point to the same side on connecting rod and connecting rod bearing cap
- Circlip
- Always replace
- Piston Pin
- Removing and installing. Refer to PISTONS, REMOVING AND INSTALLING .
- Piston
- Measure the piston projection at "TDC". Refer to PISTON PROJECTION, MEASURING AT TOP DEAD CENTER (TDC) .
- Mark the installation position and cylinder allocation.
- Replace the piston if there are cracks on the piston head or piston shaft
- Removing and installing. Refer to PISTONS, REMOVING AND INSTALLING .
- Check piston and cylinder bore. Refer to PISTONS AND CYLINDER BORE, CHECKING .
- Circlip
- Always replace
- Piston Rings
- Measuring the gap.
- Measuring side clearance.
- Use piston ring pliers (commercially available) for removing and installing
- Installed position: "TOP" marking or side with writing faces the piston crown.
- Offset gaps by 120°
- Bolt - 9 Nm
- Oil spray jet for cooling the piston and spray jet valve
CAUTION:
The oil spray jets could get damaged.
- Do not bend the oil injector jets.
- Check that the oil spray jet is accessible after reinstalling the pins.
- Bent oil injector jets must be replaced.
CAUTION:
There is a risk of damaging the piston crowns.
- Mark the allocation to the cylinder on the piston crown with paint to install used pistons. Do not mark the piston head with a punch, scratch, notch or something similar.
- Installation position: arrow -1- on the piston head toward the pulley side
-- Before removing, mark the allocation of the connecting rod and connecting rod bearing caps against each other with paint -arrow-.
NOTE:
Only replace the connecting rods as a set.
Do not interchange the connecting rod bearing.
The larger thrust flange on the connecting rod -arrow- faces the adjacent crankshaft bearing.
NOTE:
The front connecting rod pair is pictured here.