Crank Case Ventilation Grommet

I've had an oil leak on the right side of the engine below the carburetors. There are a couple of possible reasons that we will work on.

  1. The grommet that seals the crankcase ventilation tube to the head might be bad.
  2. There are two screws that connect sheet metal baffles to the head on either side of each carburetor. On some cars the screws penetrate through the head which can cause significant leaks if the screw is loose or missing.
  3. Oil may be coming from the oil filler tube into the air cleaner and spilling down the carburetors to the sheet metal below the carburetors.
081201_452 Here is the problem area before we started to work on it. The crankcase ventilation is through the small diameter rubber tubing that drops down from the filler to the sheet metal at the base of the intake manifold just below the carburetors. The connection from the hose to the head is via a tube that is swagged in the middle producing a ridge. There is a rubber grommet in the head that the tube goes through.

The sheet metal shields wrap around the tube tightly enough that it can not be pulled out of the head. There are 6 screws holding the flat sheet metal below the carburetors. 5 of these are easy to remove. The 6th is behind the intake stacks and is difficult to access.
081201_454 Note the new grommet sitting on the engine mount.

Access for this project is greatly improved by removing the air cleaner and carburetors. The latter is easy, requiring snapping off the throttle linkage, disconnecting the gas line and removing the four mounting nuts to the intake manifold.

At this point the rear screw just behind the manifold can be accessed as well as the screw holding on the two shields that cover the spark plugs. This screw is accessed from between the two horns of the intake manifold.
081201_455 When the shield covering the front spark plug is removed the tube in the grommet and the grommet can be removed and the new one installed.

It may take a bit of pressure on the sheetmetal at the rear of the engine to allow everything to align properly for reassembly.

After 5 days of operation, the leak has not reappeared.

The next oil change will have to be monitored carefully to be sure oil does not get into the air cleaners.
Last modified: Sun, 12 Aug 2001


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