1941 Packard

[Guest mikemc]

I just purchased a 41 Packard 160. I changed the oil and took it on a 200 mile tour a couple of weeks ago. Everything went fine. However after about a 100 miles the oil gauge needle just flipped to the right and stuck there. Is the gauge bad or has some oil line blocked? Suggestions on how to fix would be appreciated. Also the temp gauge moves just barely above the cold side and stays there. Any thoughts? Love the car! Thanks, Mike

[Rusty_OToole]

Get another oil gauge. Disconnect the oil line at the engine and try the other gauge. You may have a bad oil gauge OR your pressure relief valve is jammed.

Temp gauge could be bad or no thermostat. Again, double check it with a different thermometer. A kitchen thermometer in the rad or an electronic one aimed at the gauge sender area.

[Guest mikemc]

Rusty. Thanks for the response. Where is the pressure relief valve and how do I check to see if it's jammed?

[Owen_Dyneto]

The oil pressure relief valve is in the oil pump body which is on the passenger side of the lower engine. Remove the hex-headed plug - out should come a spring and plunger. You want to make sure the plunger moves freely within the bore.

As to running cold, of course check the actual temperature but let me ask, are the radiator shutters stuck in the open position? You do have a second thermostat in the upper radiator tank that activates the shutters, in addition to the thermostat in the cylinder head gooseneck.

[Guest mikemc]

Thank you...is the pressure relief valve something unique to the Packard? I've not heard of them before. Regarding the radiator slats...yes, they are opening and closing fine. I'm looking forward to working on the relief valve today.

[Rusty_OToole]

Every car has a pressure relief valve. Otherwise you would get enough oil pressure to blow the filter right off the engine (have seen this happen).

If the piston gets gummed up with sludge you need to take it out and clean it off. Brake clean spray or carburetor cleaner or lacquer thinner works for this. Luckily your Packard's is accessible without taking the oil pan off.

Make sure you put all the parts back in the right order.

[Guest mikemc]

This is getting more interesting. First of all, I still can't find the Oil Pressure Relief Valve. I've found the oil breather tube...and right in front of it is a 1/4 inch copper tube coming out of the manifold that drips some oil. Is it close to that area? Secondly, I read an old Packard Service a letter last night that says if needle goes all the way to the right, it's probably because the gauge is not grounded properly and to "just put a drop of solder on it". I crawled under the dash and saw that I'd have to take off the entire cover plate to get to the gauges. Is there a simpler way? Thanks again for your help

[Rusty_OToole]

You could start by listening to what I told you in the first place. If you go back to my first post you would see that if you took a known good gauge and connected it in place of the car's gauge, you would know in 1 minute if the problem is the gauge or the oil pump.

1) Test oil pressure with new gauge

2) If the gauge is faulty, repair or replace

3) If the pump has too much pressure, clean the pressure relief valve. The pressure relief valve is on the oil pump.

If you feel you are in over your head, you should try to find a good mechanic who is familiar with the older models of cars. If there is an antique car club in your area the members will be able to help.