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1955 Buick low oil pressure?


old-tank

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On my last cross country trip to Spokane and back to South Central Texas the indicated oil pressure was lower than usual.  Added STP helped a little.  So now I need to see if it's the gauge or if the oil pressure is really low.  I wanted a way to observe the original gauge and check  the numbers with another gauge.  So this is what I came up with:

 

IMG_20230919_085308220_HDR.jpg.04499b67aa13bda774bd30c1213f523e.jpg I drilled and tapped for a fitting to add an external gauge to an extra oil filter canister.  IMG_20230919_093823167.jpg.cf92c71329f4c689cc927404ae7e60fc.jpg

Cold start idling at 1200 RPM... Gauge in the car was showing the needle at the upper end of the normal range.IMG_20230919_094745225.jpg.44dce971bdc85c939cedf324954065e0.jpg 10 minutes later... gauge in the car with the needle in the middle of the normal range.IMG_20230919_095018059.jpg.20aff6e1c89ba1a2033a4006b5953db3.jpg

 

Engine idling with their car in drive.... gauge in car at near zero.

 

Oil pressure comes up to about 28 at 3,000 RPMs.

 

Overall the car runs great with no noise from the main or rod bearings no valve train noise.  Oil pressure is adequate for short local driving but I won't attempt any cross country trips on this car until I find out what's really wrong and fix it

 

So I guess the next step will be to pull the pan and check the oil pump and there may be a delay in the next reporting since it's still hot in South Texas.

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31 minutes ago, Dandy Dave said:

Check the relief valve in the oil pump. Could be something stuck in it holding it open slightly. I've seen, and fixed, this problem in different engines before. 

 

Agree.......and check for a cracked internal oil line if it has one. Sometimes solder joints in them leak when warm. Best bet is to use an oil pressure pot with the pan down and look for it.........hot if possible. 

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3 minutes ago, edinmass said:

 

Agree.......and check for a cracked internal oil line if it has one. Sometimes solder joints in them leak when warm. Best bet is to use an oil pressure pot with the pan down and look for it.........hot if possible. 

I like em hot.  Fire up the BBQ Willy. Have a thermometer ready. I found one for making candy works well. 

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5 hours ago, edinmass said:

 

Agree.......and check for a cracked internal oil line if it has one. Sometimes solder joints in them leak when warm. Best bet is to use an oil pressure pot with the pan down and look for it.........hot if possible. 

Since I love working under a drippin engine with the pan off, that should really make my day!:o

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4 minutes ago, old-tank said:

Since I love working under a drippin engine with the pan off, that should really make my day!:o

 

BEEN THERE, DONE THAT....

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I would get up there and TEE my test gauge right off the pressure port. It would be nice to assume that filter housing tap would show the system pressure but with the side stream flow on that filter arrangement you could get tricked.

 

I am not sure but the oil filter lines may not go from a pressurized oil galley to the crankcase. Just suspicious. If it does that could explain the test pressure drop.

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55 minutes ago, 60FlatTop said:

I would get up there and TEE my test gauge right off the pressure port. It would be nice to assume that filter housing tap would show the system pressure but with the side stream flow on that filter arrangement you could get tricked.

 

I am not sure but the oil filter lines may not go from a pressurized oil galley to the crankcase. Just suspicious. If it does that could explain the test pressure drop.

Thanks for the response Bernie.  I was assuming that a full flow system would show pump pressure at the filter since the oil under pressure goes first through the filter.  A tap at the side might show higher pressure since that is pre-filter.  The reason for checking is because the stock gauge is reading low and all I needed to know was it the gauge or is the pressure really low.  And the main reason I did it this way  the pressure port is hard to get to (the nailheads in your cars might be the same).

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17 hours ago, old-tank said:

the pressure port is hard to get to (the nailheads in your cars might be the same).

 

They are hard to get to for sure. My '60 Electra had an oil level half way across the gauge when I bought it. That piping got eliminated quickly before I felt hot oil on my leg.

 

I am not much for add on gauges. I believe any well maintained system is more reliable that a monitoring gauge. In the refrigeration side of my life  found that Liebert computer room AC units strive for 100% reliability. Years ago I discovered that company eliminated compressor oil pressure safety switches because they caused more downtime that the compressors. Studying other types of systems I found that to be a generally universal concept.

 

I looked at your housing and brain farted. I thought it was a side stream like this Cadillac one at the far right of the picture.

IMG_0307.JPG.c79e51089b1c0eb84a4b7ff987e61ea5.JPG

 

 Yours would be full flow and the tap should show the system pressure. Interesting problem, one that I would like to have right under my nose to solve.

 

I was diagnosing a problem with that engine in the picture, started it with the oil filter off. That was the Jed Clampet moment of my life. But I got it cleaned up.

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In one respect, as long as the lifters are quiet and no other not-desired sounds occur at any time, no real concerns (as if the watning lights were always unilluminated after starting, going out quickly).

 

On the other hand, knowing what the pressure is on the gauge can be good too.  You can always hold the gauge "accountable" that as long as the pressure is in the "Normal" range, it is fine.  Just watch it to see how it acts, like if it takes longer to rise upon first start or heads more toward "0" at idle.  In an old 1950 Plymouth service manual, on the issue of oil pressure, it stated that ANY oil pressure at idle is good, as long as it then increases with engine speed.

 

How long has the pressure been lower than it used to be?  Might it be time to install a quality electric gauge for verification?  Would be interesting to see how much wear is on the main and rod bearings, via Plastigage.

 

Please keep us posted on what you find.

 

Now that it's being in the lower 70s in the mornings, makes me feel like I need to grab a coat.

 

Just some thoughts,

NTX5467

Edited by NTX5467 (see edit history)
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Checking bearing clearances is planned unless I find something drastically wrong with the oil pump.  When I had the transmission out for a new seals I checked the rear main bearings.  Plastigauge showed no wear and the thrust was okay too.

It is still hot here 79 to 99 so the teardown will wait.

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I am not real busy today. Drop the car off at my place and I guarantee the gauge won't read low any more and things will be fine.

 

Remember in the 1970s when GM had oil lights flickering at idle due to higher operating temperatures with emissions controls, they put in lower pressure sending units.

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45 minutes ago, 60FlatTop said:

Remember in the 1970s when GM had oil lights flickering at idle due to higher operating temperatures with emissions controls, they put in lower pressure sending units.

But all it usually took to fix a flickering "GEN" light was a screwdriver or some wrenches, just depending on the severity of the issue.  Maybe even a wire brush for the battery connections?

 

Enjoy!

NTX5467

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  • 3 weeks later...

Bearing material is green?

Edited by Frank DuVal (see edit history)
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How many miles (total) on the engine?  When did Buick switch to insert bearings for the camshaft?  Seems odd that they wouldn't have eliminated the poured bearings all at once.  At least you'll have cooler temperatures in the garage for awhile...

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9 hours ago, Frank DuVal said:

Bearing material is green?

Chunks of silver on my display.

3 hours ago, EmTee said:

How many miles (total) on the engine?  When did Buick switch to insert bearings for the camshaft?  Seems odd that they wouldn't have eliminated the poured bearings all at once.  At least you'll have cooler temperatures in the garage for awhile...

miles...125K

insert switch...don't know

Going to put it back together so I can move it around.  Researching options:  rebuild, replacement engine, cam bearing replacement.

Last time I needed a small job like cam bearing replacement all of the machine shops insisted on complete disassembly and tanking of the block.

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Yep, cam bearings are like step ONE of any rebuild.... except in Corvairs where there are NO cam bearings, just aluminum journals machined into the block, which are now wearing large.... wish there were inserts now.... 😱

 

Silver hunh? They are mostly bearing color chunks, but I see several green pieces, like the green triangles in my vibratory tumbler. Moving the laptop screen at different angles they are still green. But I can understand different monitors display very different colors. 👍

Edited by Frank DuVal (see edit history)
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Talked to machine shop...engine needs pulled of course...needs total disassembly, tanked then inspected, total rebuild...up tp 2 months.

Gas will be stale by then and I will have forgotten how to put it together.  Looking for a running engine now.

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On 10/16/2023 at 2:15 PM, NC-car-guy said:

No offense but won't it really limit your search if you have to know the person first?

No offense taken but after buying parts and cars since the 1980's there have been some "disappointments" in the representation of the items.  If the items were close by so I could my own inspection...maybe.  If buying from BCA members who are friends...for sure.

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