Packard Forum Index » Pre-War (1899-1942)

After driving my 336 for over 50 years I always found my motor to run in the driving range even up the steepest hill. I would suggest look for the easiest things first as long as it sounds like you have done everything necessary. There are two things that you may have done but I will mention them in case I missed them in the thread. I have had problems with modern anti-freeze that contained too much silicate so I use a low silicate anti=freeze to reduce any overflow burp, also it is important to use a thermostat to stop any overflow burp.

good luck

The coolant problem is solved. The engine developed a serious noise back in March just as we were about to go to the ferry and then join in the 2015 National Packard Rally at Hawkesbury in Sydney Australia.
I took the head off and found a valve seat insert had come free and had been hammered to death in the cylinder.
The block crack at the 5th cylinder had opened up and that appeared to be the main cause of the |"burping".
I replaced the block with a spare one off an earlier model- it has a 3 3/8"bore. We have had lots of other problems with head gaskets leaking. One roller cam follower decided to loose its roller. Finally the engine is leak free apart from some oil!! and it does not eject any coolant when under load. The smaller bore does not seem to make much difference to the power.

Phil,

Although it's been a major sorting put exercise it's great to hear the Packard is now running well!