41 merc v8 oil pressure
 

my 1941 Mercury V8 just today had the Oil Pressure PEGGED.
double checked my oil level, ok. It has been running about 1/2 of
the gauge. changed the oil about 50 miles ago, 15W-40 diesel oil
for the ZINC.


what is wrong, etc., is this a major concern or YIKES ??


stay safe
thanks
G&U

Re: 41 merc v8 oil pressure
 

Check with a mechanical gauge
Maybe bad sender unit

Re: 41 merc v8 oil pressure
 

duh.... you are correct! I should have thought of that, but sometimes I have a "brain fart".... will get one tomorrow. would you be kind enuff to tell me where it is located, more or less? ordered a shop manual, but not here yet. stay safe. thanks

Re: 41 merc v8 oil pressure
 

On top left side of bell housing right behind left cylinder head

Re: 41 merc v8 oil pressure
 

How much oil did you put in? Mike

Re: 41 merc v8 oil pressure
 

Just to add, there are two ports in that location but one is likely plugged. You should be able to remove the plug and find a fitting that will fit the plug size so you can attach a hose with your gauge on the other end. An automotive oil pressure gauge kit may supply what is needed to tap in there. Check your sending unit there for wiring problems or the like. A short could peg the indicator.

There were two difference senders used back in that time frame. Yours should be the 48-9278 unit that is a 50 PSI unit. During the war they changed over to 80 psi indicating systems that used a different part number sender but it was used with an 80 psi indicator gauge. This led to parts confusion so the new type usually has 80 psi on it somewhere. the old 50 psi one didn't need anything stamped on there.

Re: 41 merc v8 oil pressure
 

I think (sometimes) that I put 4 maybe 5 qts 15w40 diesel oil in it when I changed the oil.... I used the Dipstick as my "judge"... did not overfill.... found the 6V sending unit, and there is a blanking plug that I intend to connect a mechanical gauge into..... so... MURPHYS STRIKES AGAIN... now that the oil pressure has been remedied …. I had been having problem with my Trunk not closing..... not concerned about it, as it is something I can take care of in time.... then... my neighbor SLAMMED the Trunk shut, and yep, won't open. tomorrow intend to take the nuts holding the Lid on hinges loose and maybe I can open it without taking the nuts off completely, but will if needed.... and my neighbor said "I fixed it" and left before I really found out how "good he fixed it"..... wheeeeeeeeeee…. stay safe. thanks

Re: 41 merc v8 oil pressure
 

I'll take it that you don't have an oil filter. I plugged the port that would have normally supplied the oil filter, removed the 6v sender and installed a mechanical gauge. I think the new gauge has a problem because I'm showing 70 pounds of pressure even after the oil is warm. Good luck and let me know what you come up with, please?

Re: 41 merc v8 oil pressure
 

40 w oil