Packard Forum Index » Post-War (1946-54)

Looks like the nuts on the manifold-exhaust connection backed off. They need to be torqued to the correct spec.

I don't know if it can really affect the power that much, but it could mess with the mixture. More probably, the engine was noisy which made you rev it less than you might have otherwise, which would make it feel less powerful.

You certainly want to tighten that back up. You might also need a new gasket in there if the old one has come apart.
Tighten it down first and see if it stil leaks or not.
Big exhaust leaks like that can mess with power and engine performance.
When I see that the downpipe was not tightened correctly, then I would also question if the rest of the manifold nuts were torqued properly. It would be wise to check the torque on all the manifold nuts, and also check ignition timing.

Thanks for all of your comments. You members are the best!

I took the car to a local muffler shop and the bolt on one side of the exhaust/manifold connection had flown off. They were able to align the flange but could not get it tight enough. It looked like the original gasket.

I ordered a new gasket from Olson’s and it came in 2 days. Great service!

I returned to the muffler shop this morning and they were able to install the new exhaust flange gasket without any cutting. The gasket looks like a big o-ring and Olson ‘ said in was like the NOS one.

The car now much quieter and running better, I think.
I’m going to try the vacuum gauge again later.
Thanks, again for your help.

Olson’s service is great and is fast even on custom gaskets! I used them all the time.

The metal-sheathed o-ring type seal is the proper one and make sure that the heat riser in the exhaust manifold is working properly too.