News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

1954: Having Oil Pressure Problems

Started by DUC, October 19, 2011, 07:16:30 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

DUC

Hey guys, here's another one for you to think about.

I'm have oil pressure problems on my 54 series 62.

Here's is alittle history on the car. The previous owner had bought the car from a mechanic shop that had rebuilt the motor in the car (or atleast remove/installed it in the car after the rebuild) about 10 years ago. The motor had never been ran until about April of thise year. Before I ran the motor I installed a oil pressure gauge. Inside of the motor was clean like it was done recently. Ever since the first run in the pressure has been around 20-25 psi at any rpm. What could cause the low pressure and is it ok to run this pressure?

Note:
I've read kits being sold with the wrong spring (stiffer spring tension causing higher pressure), and I alse read there is a plug some where there is a plug on the inside of the block in front of the distributor gear not being there causing lower (4-5psi) pressure.
Chris Henry

1954 Cadillac Series 62 Sedan

Dave Shepherd

To be sure try and get/use a back up gage to confirm those readings,  also is the  oil fresh?  After that you would have to confirm the condition of the pump and the proper press. relief spring, then it gets tough, many internal clearance issues can cause low pressure, cam and crank bearings being the most common.  Of couse any internal oil galley plug left out can cause issues also.

DUC

#2
The first gauge I had on there was a new-ish gauge I borrowed and was reading maybe 25-28psi. The gauge I'm using now is older. I might just go buy a new one to check again and I'll check the plug by the distr gear. The oil is fresh 30w w/ break in zinc additive and about 24 miles and 40 minutes (not at once) in neutral on the oil. Are there anymore galley plugs?

I just watched a video stating clearance issue = low pressure.

Chris Henry

1954 Cadillac Series 62 Sedan

Eldovert

I would lean towards a sticky relief valve or weak spring.Those small galley plugs are 1/2 inch in diameter and would result in a drastic pressure drop if one was missing.
Cheers,Pat MacPhail

DUC

#4
I bet the regulating spring retainer is missing! I'm racking my brain wondering why the pressure is staying constant though. It's going to be a big pain to pull the oil pan with the motor in the car.
Chris Henry

1954 Cadillac Series 62 Sedan

62droptop

one has to be careful with a rebuilt engine that has sat a long time before running
i ran into this years ago,i had a brand new short block that came with one of my english cars
was about 12yrs sitting when i bought it
i removed the bearing caps to fin the oil /breakin lube had turned into a dry gel type substance that most likely woul have damaged the bearings if i had turned the engine over
glad i pulled it apart

this also goes for any engine that has been standing for a long while
i use a pressure luber before i start any engine that has been rebuilt or standing for a long time
that way i have full oil pressure before i even crank it over
i hope you find a simple issue like a relief valve incorrect or stuck open


Jay Friedman

Dropping the oil pan is not that hard.  Unbolt the idler arm on the passenger's side of the car and lower the steering mechanism.  I don't think you have to remove any exhaust components on a '54 with dual exhausts (no crossover pipe).   Remove the starter and then you should be able to remove the oil pan.  Remove pan and oil baffle and then the oil pump is then easy to remove. 
1949 Cadillac 6107 Club Coupe
1932 Ford V8 Phaeton (restored, not a rod).  Sold
Decatur, Georgia
CLC # 3210, since 1984
"If it won't work, get a bigger hammer."

DUC

#7
Quote from: 62droptop on October 19, 2011, 09:17:38 PM
one has to be careful with a rebuilt engine that has sat a long time before running
i ran into this years ago,i had a brand new short block that came with one of my english cars
was about 12yrs sitting when i bought it
i removed the bearing caps to fin the oil /breakin lube had turned into a dry gel type substance that most likely woul have damaged the bearings if i had turned the engine over
glad i pulled it apart

this also goes for any engine that has been standing for a long while
i use a pressure luber before i start any engine that has been rebuilt or standing for a long time
that way i have full oil pressure before i even crank it over
i hope you find a simple issue like a relief valve incorrect or stuck open

62droptop
I primed the motor before I started it. Sat there with a drill with a modified flat blade screw driver shank for about 3-5 mins or so while rotating the crank at the same time.

Jay, I'm just worried about the nice seal on the oil pan... no drips. lol But, I have to do it.

Chris Henry

1954 Cadillac Series 62 Sedan

62droptop

the drill method also works great when you can access the pump drive, i also use that method when i can,it is nice to get the actual oil pump involved with the equation

i know what you mean about breaking a perfectly sealed motor!

good luck and may you find  a simple cheap solution :)!!

DUC

Cheap is good as cash is tight right now. I'm hoping for easy too. lol
Chris Henry

1954 Cadillac Series 62 Sedan

signart

My question is, what makes you think 25lbs is too low? A steady pressure reading at any rpm or temp. of 25lbs is a good thing, I would think in a stock engine. Art Woody.
Art D. Woody

Caddy Wizard

20-28 psi is not low oil pressure.  So that in and of itself is not a problem.  At idle, you need a minimum of 10 psi and at speed the pressure should be at least 25-30.


The real issue is the steadiness of the pressure regardless of rpm.  I am guessing that the spring is missing or broken or the pressure relief valve piston is stuck open.  So regardless of engine operating conditions, everything above a certain pressure is bleeding off.  The reason you have good pressure at all, even in the absence of a properly working pressure relief valve, is that everything is new in the engine and the main bearings and rod bearings are holding excellent pressure.  Over time, this could become a problem as the engine wears.  So you are wise to address this now.


The bottom line is that, to me, this sounds like a basically sound rebuilt engine that just needs the oil pressure relief valve looked at.  Drop the pan (no big deal) and pull the oil pump to investigate.


Art Gardner
Art Gardner


1955 S60 Fleetwood sedan (now under resto -- has been in paint shop since June 2022!)
1955 S62 Coupe (future show car? 2/3 done)
1958 Eldo Seville (2/3 done)

DUC

Where can I buy a spring if it needs to be replaced?
Chris Henry

1954 Cadillac Series 62 Sedan

DUC

#13
I got the pump out, it was a pain since I had such a good seal on the oil pan. I have it all apart and clean, the valve wasn't sticking or stuck. I do think the spring is week though. 

The service manual says to check the free length, compression, and lbs.

Specs:
Free length 2-25/64
Compresed is 1-13/32
5-3/4 to 6-1/4 pounds.

Mine:
Free length 2-18/64
Compressed 29/32
Pounds not sure

I would just shim the spring to preload it but I'm not certain how many shims (washers) to put in. Maybe enough to make up the difference. I would rather do it right with a new spring. Anyone know where can I get new?
Chris Henry

1954 Cadillac Series 62 Sedan

Eldovert

I believe they are the same as small block Chev....in my youth I put one in my '56 coupe from a Z 28..don't ask >:D
Cheers,Pat MacPhail

Dave Shepherd

Quote from: DUC on October 23, 2011, 01:23:19 AM
I got the pump out, it was a pain since I had such a good seal on the oil pan. I have it all apart and clean, the valve wasn't sticking or stuck. I do think the spring is week though. 

The service manual says to check the free length, compression, and lbs.

Specs:
Free length 2-25/64
Compresed is 1-13/32
5-3/4 to 6-1/4 pounds.
Don't shim the spring that is guess work at best, also pan down, I would look at the bearings maybe even plastigage them, could be another source of low oil pressure.
Mine:
Free length 2-18/64
Compressed 29/32
Pounds not sure

I would just shim the spring to preload it but I'm not certain how many shims (washers) to put in. Maybe enough to make up the difference. I would rather do it right with a new spring. Anyone know where can I get new?

DUC

#16
I found more information under the specifications section.

OIL PRESSURE REGULATOR

Clearance between valve
plunger and housing--
New limits.............. .0020-.0035"
Worn limits, not over... .005

Normal pressure to 30
M.P.H. (min)............ 30-35lbs
Idle (average).......... 15lbs

Spring --
Free length (approx.)... 2-27/64"
Pressure at 1-7/16"..... 4.3-4.8 lbs
Vave opens at............ 30 lbs
Chris Henry

1954 Cadillac Series 62 Sedan

DUC

I was able to check the second main and it was .0015.

New limits............... .0008-.0025
Worn limits, not over.... .005

Ill have to try to check the other sometime this week.
Chris Henry

1954 Cadillac Series 62 Sedan

DUC

I have everything back together and running. So far its holding at 30 psi. I guess the pump/relief valve needed to cleaned. I don't know if shiming the spring did anything.
Chris Henry

1954 Cadillac Series 62 Sedan

Eldovert

Chris,
Glad you solved your problem.
Cheers,Pat MacPhail