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

Hey gang. I've been running my freshly rebuilt mechanical fuel pump. I've never had the car run on its mechanical pump until recently. Went out for errands and driving around, ran great. No vapor lock, no missing, spark plugs read normal - all good.

I was re-torquing my manifold nuts and noticed a little splatter mark on the inside of the fuel pump heat shield. Wondering what's going on here. It looks like it would have come from the rectangular opening on the side of the pump. Is this normal? There aren't any puddles or drips, and the line isn't wet. I do have an electric pump as well, but it was only run briefly before I learned I needed to install a bypass line. Or maybe it's an incidental finding. I recently de-greased (with a spray can) and cleaned all my grease fittings; maybe something from that? Just want to make sure the diaphragm isn't already failing or something... Thanks, all!

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Did you use Teflon tape on the fittings? It is not compatible with gasoline and is not needed anyway as the NPT threads are self-sealing due to the taper.

No, sir, I used small amounts of Permatex thread sealant with PTFE (read that was the fuel safe/carb safe option). I used it on connections that relied solely on the thread to seal the connection, assuming that any wear on the threads would lead to a leak. Just wanted to cover my bases.

The spatter is probably crankcase oil or perhaps assembly lube placed on the pump lever mechanism by the rebuilder or installer.

I'd wipe it clean and keep an eye on it, but I don't think it indicates a problem.

Don't overfill your crankcase. No good will come of it.

Looks like a dual function pump/vac/fuel.
I like to put a fuel pressure and vacuum gauge on my old cars to help diagnose what's going on. Those small 1" round ones.
If the pump was rebuilt and installed correctly, and is putting out the right pressure, then it should not leak for some time. But no way to look at a picture of some stain and diagnose issues over the internet. That's wishful thinking. I'd go around and check the screw tightness just to be sure. Sometimes they get missed uneven torq.
In a dual, if the diaphragm leaks it can go into the vacuum side and not be noticed at first.
I was having a rash of bad new mechanicals and opted to go full electric. It was a manufacturer issue, not a rebuild. Whatever works.

The slot or opening in the pump is a vent to the crankcase and it looks like you've got some crankcase oil mist expelled, probably from engine blow-by. Are you sure your crankcase breather system is clear and functioning? In any case it's not entirely untypical and I'd just keep an eye on it for a while. Probably nothing to be concerned about.

Thanks so much for the thoughts on this, everyone! I'll continue to monitor, but the venting/blowby makes sense. The car is actually also running a cleaned and freshly oiled breather cap for the first time since I've had it as well (was previously a pressed on cap from Rock Auto). I've slowly tracked a lot of new-old (but original) things that have been missing from the engine, put them back on the car, and it's all still relatively new to me, my driving experience, and my care and maintenance of the engine. Keeping up with my owners manual and trying to search this stuff out. I promise it has 7 qts. of oil and no more. Thanks again, everybody!

I believe that at some point, Packard changed the oil capacity specification for the 120 engines from 7 quarts to 6 quarts. I came across that information in a monthly service bulletin in the literature archive on this website.

The change was not related to the presence or absence of an oil filter.

I would assume that adding an oil filter would require an additional quart, but that may be where the confusion over published oil capacity came from.

I don't recall seeing 8 quarts specified for the 120.

It may be that 7 quarts was needed for a new or rebuilt engine, and 6 quarts for a refill following a routine oil change.

You might check for a suffix letter or some type symbol like a star stamped at the front or end of your motor number.

Packard usually added a suffix if there was some change from the original as introduced spec. Some changes have to do with a particular component construction or a substitution if a part was in short supply and something different was installed. Postwar years also had a suffix for changes in oil pan capacity and prewars probably did too. Some but not all the suffix meanings are found in service letter articles. If not mentioned perhaps someone on the forum has a different bulletin and can say what a particular letter or symbol means.

Symbols were most often used in denoting something was over or under sized in machining and a special part is needed if the item is replaced. Those were only on the very few engines affected.

I should have specified... I'm working on a 2302-5 ('50 Super Deluxe Eight) with the 327. I usually just maintain my oil level on the dipstick, which indicates seven quarts. The car itself isn't new to me at this point, just some of the components, and I'm still understanding how they operate both normally and when they fail (or need maintenance), namely the mechanical pump (the electric pump is still there, but have wanted to run the car on the mechanical as the primary), crankcase breather, and the oil bath air cleaner. Sorry for the confusion!

In this case, I was just more worried that I'd get responses like "Splatter mark, uh oh! Well that indicates the grenade-shaped object on the side of your engine is about to pump all kinds of gas into the crankcase and indeed do its best impression of a grenade!" Seems like we're not there yet.