'05 E320 CDI oil cooler seal replacement - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 06-04-2022, 03:45 PM

Having done the oil cooler seal replacement job on the OM642 (V6) twice, doing the same job on the OM648 is super easy! I could not park my CDI on mine or anyone else's driveway without leaving black oil puddles, so I bought the seal (less than $5), and proceeded to do the job. Actually, the hardest part is removing the three screws closest to the block. However, with a short wobble socket extension, and a 1/4" ratchet, it was not that hard. The first thing is to drain the coolant, and remove the splash gaurds. Next, loosen the belt using a 12 point 17mm socket on the belt tensioner, and slide the belt off the power steering pump pulley. Next, remove the three bolts holding the PS pump (E12 socket), and move the pump out of the way. In order to get the coolant hose off of the cooler, the plastic part (not sure what it is called) connected to the charge pipe needs to be removed, and pushed rearward in the cavity between the manifold and block. It takes an E10 socket to remove the three bolts. You now have room to remove the coolant hose, and to remove the five screws holding the oil cooler to the housing. When the cooler is removed, some oil will drain out, so have a drain pan placed underneath. Install the new seal, and install the parts in reverse order. You can choose to either clean the block and parts below now, or de-grease and pressure wash after the entire job is done (with the splash guards off of course). The entire job only took me about an hour.....Rich

ROLLGUY · #2 06-04-2022, 03:49 PM

The new and old seal, and ready to clean and install the parts.

IMPORTANT!!: Be sure to remove the thin plastic tube at the expansion tank before working, as you WILL break it! (don't ask me how I know this!)