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Oil Cooler

Table of Contents

About

The oil cooler on SD33 engines is located on the RH side of the engine, towards the top-rear corner of the block (behind the injector pump, above the oil filter and underneath the secondary fuel filter).

It is a simple system, with oil from the filter housing being pumped through tubes and into a sealed ‘radiator’. Engine coolant coming from the block is pumped around the radiator, before returning into the heads (Direction of coolant flow presumed, path is correct).

Removal

It is a simple job to remove the oil cooler.

You should only do this when the engine is cold, or you may be burned!

  1. Remove the oil transfer pipe.
  2. Remove the support bracket for the fuel pipes.
  3. Remove the large banjo bolt to the head.
  4. Remove the cooler housing from the block.
    It is recommended to remove the bolts in a spiral pattern, similar to removing a head. This is to minimise any warping to the cooler.
  5. Separate the radiator element from the cooler housing.

If the cooler has never been removed, it will likely require some persuasion. Be gentle, you do not want to damage the mating surfaces or warp the cooler. Coolant leaks may occur due to a poor seal.

Cleaning

As seen in the photos, corrosion and scale from the engine gets trapped in the radiator, causing a large blockage. Hot oil can be a major contributor to engine overheating problems, so checking and cleaning the cooler is a worthwhile task. It is even more vital on turbo engines, as the turbo heats the oil to even higher levels.

A ‘backyard’ coolant flush is insufficient to clear the buildup. The photos below were taken after running the garden hose through both radiator hoses, the heater hoses and through the block drain bolt. Clean water was flowing from the entire engine, then the cooler was removed and photos taken.

Installation

Assembly/installation is the opposite. Take note of the following;

  • Check the cooler housing for flatness. You may need to file/sand it flat, or risk leaks.
  • There are 2 paper gaskets for the radiator element to the cooler housing and 1 paper gasket for the cooler housing to block. New gaskets and a suitable gasket-goo should be used when re-assembling.
  • There are 4 o-rings for the oil transfer pipe (one at each end of each ‘pipe’). These may need replacing.
  • The banjo bolt is sealed with copper washers. Gasket-goo may be required to obtain a good seal, and/or new washers used.

Upgrading

It would be possible to install a remote oil cooler.