How to Flush the Oil Cooler?
 

I'm still working on swapping the engine in the 300D . . . the service manual suggests flushing the oil cooler and lines and anything else that may have been exposed to the oil in the seized engine . . . for fear of metal shavings I assume. What should I use to do this? Not water, right? Maybe some horribley caustic chemical?

Thanks,
Eric
'71 220D
'81 300D

use diesel.

If you can get the cooler off the car it will be easier too.

Like kmaysob suggested use diesel. With the oil cooler still in the car attach a transmission funnel to one oil cooler hose end with a piece of hose and hoseclamps. Put the other oil hose end into a container. Empty 1 gallon milk jugs work nicely. Pour diesel through the hoses/cooler to flush it. Suggest backflushing in the opposite direction to oil flow. When you are done use compressed air to blow out any remaining diesel/oil to clear the lines. Recommend you empty the catch container before using the compressed air or you will have a mess. RT

Man oh man be careful. It the oil cooler lines have never come off before they will in all likelyhood be siezed on the aluminum threads of the oil cooler. Once you take off the old oil cooler lines the resulting threads are usually shot. You can do it if you are mighty careful but why bother? Just change your oil every 1000 miles for a few months and your done. (my .02)

Billrock -

What about disconnecting the oil cooler lines at the other side (I have to anyway) and flushing the cooler with the lines still on?

Eric

He was doing a swap.................something has to be disconnected to pull that off.