I have not had an oil pressure issue with my 53 Chevy since I have owned it. It has a later model 235, out of a 57 pickup truck, and seems to run pretty good.
Last Thursday I decided to drive the old truck to work and back and haven't started it since getting home, until this afternoon, when I decided to take it for a short drive into downtown. When I started it, I noticed it taking several seconds for the oil pressure gauge to come off 0 and obvioulsly the engine was making noise until the oil pressure came up.
I thought it was odd because it had never done that before, but the oil pressure did come up and was normal so I went ahead and drove it.
It sat for a couple hours before heading home, and when I started it, I experience the same issue. I am not sure if I have a clogged oil pick up screen, an oil pump going bad (aren't they gear driven?), or what exactly is going on.
Just wanting to ask you all, where you would start looking for the issue.
Kevin, your oil pump is driven by a blade on the bottom of your distributor shaft which fits into a slotted shaft on the oil pump and the pump is just two gears spinning which act as a pump. A gear on the camshaft drives both the distributor and the pump.
The pickup screen might be plugged but if it was I would expect it to be uncommon for the pressure to come back up to normal...that is to say I would expect a plugged screen to cause a lower pressure constantly. Have you noticed oil leaking anywhere? An oil pump failing might cause this. Often if that's the case, oil pressure at idle will go pretty low.
Have you changed your oil recently and did you by any chance use a synthetic oil or thinner oil? That might be the case. Oil that is too thick can also cause this as it might take more effort for your pump to circulate it at startup, but I doubt it is cold in Joplin now.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Kevin, your oil pump is driven by a blade on the bottom of your distributor shaft which fits into a slotted shaft on the oil pump and the pump is just two gears spinning which act as a pump. A gear on the camshaft drives both the distributor and the pump.
The pickup screen might be plugged but if it was I would expect it to be uncommon for the pressure to come back up to normal...that is to say I would expect a plugged screen to cause a lower pressure constantly. Have you noticed oil leaking anywhere? An oil pump failing might cause this. Often if that's the case, oil pressure at idle will go pretty low.
Have you changed your oil recently and did you by any chance use a synthetic oil or thinner oil? That might be the case. Oil that is too thick can also cause this as it might take more effort for your pump to circulate it at startup, but I doubt it is cold in Joplin now.
Jon,
I have had some time to ponder on this, and here's what I was thinking. I bought this truck back in October and hadn't driven it a lot because I had a lot of brake work and other things to do in it.I belive the old gentleman I bought it from said he hadn't changed oil in quite some time so, I bought Valvoline VR1 and a new filter and channged the oil a while back. What I was just thinking is, I wonder if some sludge broke loose and is partially clogging the canister oil filter. The oil I used is 30W
Kevin
Last edited by kthomas; 05/04/202612:13 AM. Reason: Wanted to add another comment
Since the oil filter takes a tiny volume of oil from the main oil gallery, strains it a little, and dumps it back into the oil pan, it has no effect at all on oil pressure. A lot of stovebolt engines were sold without a filter, since it was an extra cost dealer-installed option. The most common cause of low oil pressure and/or slow pressure buildup is worn connecting rod bearings. Drop the oil pan and inspect the bearings before you do any more damage to the engine. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Since the oil filter takes a tiny volume of oil from the main oil gallery, strains it a little, and dumps it back into the oil pan, it has no effect at all on oil pressure. A lot of stovebolt engines were sold without a filter, since it was an extra cost dealer-installed option. The most common cause of low oil pressure and/or slow pressure buildup is worn connecting rod bearings. Drop the oil pan and inspect the bearings before you do any more damage to the engine. Jerry
Good morning, Jerry,
Understood on the oil filter, it was just a thought while thinking through the issue. As always, thank you for your input!
[quote=Jon G]Kevin, what oil pressure does your gauge show (startup, idle, running at say 35 mph)?[/qutheqote]
Jon,
I still have the original gauges but the engine is a out of a 57, so I am not sure how much actual oil pressure it is carrying, but here's a photo of what it carried at idle, and it usually runs around 35 pounds on the gauge.
Yesterday when I started it (and it hadn't been started since last Thursday), it took several seconds before the needle come off 0, then it went to 30-35 pounds. I have never had any issue with oil pressure, since I bought the truck back in October.
As mentioned earlier, I changed oil and put in Valvoline VR1 30W conventional for flat tappet and pushrod engines, and the truck has never used any oil, and in fact, I pulled the dipstick yesterday and the oil is still full and is clean.
If you replaced old worn down, thinned out oil with new 30 wt, that will be slower to come up to pressure.
Well, that makes sense, only thing is, I changed oil back in November or December and haven't had any slow oil pressure issues until yesterday, just out of the blue, so to speak.
30 to 35 PSI at cruising speed is normal for your engine.
At idle speed, anything between 1 and 15 psi is normal
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
30 to 35 PSI at cruising speed is normal for your engine.
At idle speed, anything between 1 and 15 psi is normal
Agreed, the problem I am seeing is that it is taking way too long for the oil pressure to come up from zero when the engine is started after it has been sitting a few days. I have not had that issue since owning the truck.
I believe I have two courses of am going to have to pull the oil pan and check bearings as Hotrod Lincoln mentioned.
You have described this as what I'd call a sudden event, Kevin. Oil pressure at startup was okay and then one day it wasn't. That seems to me highly connected to something you did and using VR-1 30 weight isn't in any way the problem. Something else is and it isn't typically a situation that would be associated with worn bearings in my experience. Although running the engine with no oil pressure won't be doing those bearings any good. If you're generating 35 psi while running and your rod bearings are worn to the point your startup oil pressure is down near zero...I don't know...that doesn't quite compute as I see it.
Let's try this before you go pulling off your oil pan. Disconnect the oil line leading up to your filter (the supply line) and plug the hole with a common brass pipe plug. Now start your engine and see if you have pressure showing when it starts. What I think is that the line leading out of your oil filter is draining oil back into the engine when it is not running. Now, when you start the engine, oil runs into the filter to fill it again and that might be what is causing the loss of oil pressure until the filter canister fills up again. As I said, let's try that first.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Before going to the work of pulling the pan, try spinning the oil pump clockwise with a drill motor. Remove the distributor and fabricate a pump drive shaft from the blade of a long flat tip screwdriver about the size of the tang on the bottom of the distributor shaft. It might also be a good idea to install a pressure gauge on a flex hose so you can monitor the pressure from under the hood as you spin the pump. The results might be different from what you're seeing on the dash gauge. If the pressure is still slow to build up, remove the oil pan and the oil pump, and inspect the pressure relief valve in the base plate of the pump. Jon's idea of isolating the filter canister is also a good one. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Good point, Jerry. He could isolate the filter and spin the oil pump also. That would eliminate the act of running the engine without oil being pumped enough to register at the oil gauge.
There is supposed to be a one-way valve in the oil filter...we always called it the leakdown valve and I've also heard it called other things. Normally I don't think about it. As you know it is supposed to hold the oil that is in the filter when the engine is off so the engine doesn't have to re-fill it each startup. With the by-pass filter if it isn't there or isn't working all the oil will slowly drain down and dribble into the oil pan when the engine isn't running. Given the restriction in the oil fill line of the filter, it would take a few seconds before the filter canister filled.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Been a minute since I’ve thought about this, but I think the restriction orifice in the center tube of my bypass canister is quite high in the housing. The filter stays pretty darn full all the time.
Jon’s got a good theory there, but I don’t think it would play out that way on my 235.
Oil flow through the filter is controlled by a 1/16" diameter hole in the standpipe- - --at approximately the level of the inlet fitting on the side of the housing. That means that the housing will stay at least 2/3 full at all times. It doesn't even matter if the filter happens to be plumbed backwards- - - -inlet at the bottom and outlet at the side- - - -the static level of the oil with the engine stopped can never drain down all the way. The only exception to that rule would be after a filter change when the canister gets drained and cleaned. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
You have described this as what I'd call a sudden event, Kevin. Oil pressure at startup was okay and then one day it wasn't. That seems to me highly connected to something you did and using VR-1 30 weight isn't in any way the problem. Something else is and it isn't typically a situation that would be associated with worn bearings in my experience. Although running the engine with no oil pressure won't be doing those bearings any good. If you're generating 35 psi while running and your rod bearings are worn to the point your startup oil pressure is down near zero...I don't know...that doesn't quite compute as I see it.
Let's try this before you go pulling off your oil pan. Disconnect the oil line leading up to your filter (the supply line) and plug the hole with a common brass pipe plug. Now start your engine and see if you have pressure showing when it starts. What I think is that the line leading out of your oil filter is draining oil back into the engine when it is not running. Now, when you start the engine, oil runs into the filter to fill it again and that might be what is causing the loss of oil pressure until the filter canister fills up again. As I said, let's try that first.
Thanks, Jon!
You are talking about plugging the feed line, correct? Kevin
Put a mechanical gauge on the system, see if the pressure still lags. If not, you may have an issue with your existing dash gauge and/or piping; and nothing wrong with the engine and accompanying parts and pieces.
Geoff
1955 2nd Series 3600 235 cid, 4 sp. - Current 1979 Chevy K10 350 cid 4 sp -Sold 1955 2nd Series Wide Window 283 cid 3 sp - Totaled
You have described this as what I'd call a sudden event, Kevin. Oil pressure at startup was okay and then one day it wasn't. That seems to me highly connected to something you did and using VR-1 30 weight isn't in any way the problem. Something else is and it isn't typically a situation that would be associated with worn bearings in my experience. Although running the engine with no oil pressure won't be doing those bearings any good. If you're generating 35 psi while running and your rod bearings are worn to the point your startup oil pressure is down near zero...I don't know...that doesn't quite compute as I see it.
Let's try this before you go pulling off your oil pan. Disconnect the oil line leading up to your filter (the supply line) and plug the hole with a common brass pipe plug. Now start your engine and see if you have pressure showing when it starts. What I think is that the line leading out of your oil filter is draining oil back into the engine when it is not running. Now, when you start the engine, oil runs into the filter to fill it again and that might be what is causing the loss of oil pressure until the filter canister fills up again. As I said, let's try that first.
Thanks, Jon!
You are talking about plugging the feed line, correct? Kevin
Here's a suggestion- - - - -instead of plugging the line, just remove the flex hose and the adapter fitting, and connect a direct reading pressure gauge to the existing line with a 1/8 NPT coupling. Then start the engine and/or spin the pump with a drill motor and watch what the pressure does. Be prepared to deal with a small volume of leakage from the filter housing as you disconnect the line.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
You can plug it where the line connects to the filter, but I would just remove the line from the block (oil may dribble out of the hose) and then I'd take a common brass pipe type plug and use that to plug where the line connects to the block. That's all you need to do. If what I think is happening, your oil pressure gauge should start registering the moment your engine starts. Then, remove the plug, replace the line, get a new oil filter and that should take care of it.
But while I'm typing and thinking...you did put the spring and washer on top of the oil filter, yes? That spring pushes the oil filter downward and makes it seal against the cone-shaped part of the oil filter canister. Then, oil flows into the canister on the side, flows around the filter, makes its way in through holes in the side of the filter, is filtered (sort of...not as well as it once was I'm told) and then it makes it through the filter and flows back through the center tube through a 1/16" hole. I'll attach an image so you can see it. Hopefully you can blow it up if you need to see it better. The spring is very important. Without it, there is no seal and I think (maybe tomorrow I can get up in the attic and make sure) oil could just leak back into your engine when it wasn't running.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
You can plug it where the line connects to the filter, but I would just remove the line from the block (oil may dribble out of the hose) and then I'd take a common brass pipe type plug and use that to plug where the line connects to the block. That's all you need to do. If what I think is happening, your oil pressure gauge should start registering the moment your engine starts. Then, remove the plug, replace the line, get a new oil filter and that should take care of it.
But while I'm typing and thinking...you did put the spring and washer on top of the oil filter, yes? That spring pushes the oil filter downward and makes it seal against the cone-shaped part of the oil filter canister. Then, oil flows into the canister on the side, flows around the filter, makes its way in through holes in the side of the filter, is filtered (sort of...not as well as it once was I'm told) and then it makes it through the filter and flows back through the center tube through a 1/16" hole. I'll attach an image so you can see it. Hopefully you can blow it up if you need to see it better. The spring is very important. Without it, there is no seal and I think (maybe tomorrow I can get up in the attic and make sure) oil could just leak back into your engine when it wasn't running.
Hey there, Jon,
Yes sir, the canister cap does have the spring and it's intact. I went ahead and ordered a pressur gauge like Jerry suggested (should be here Friday, then I will go to the hardware store and get tht 1/8" coupler and, I will removed the supply line at the canister, istall the gauge and see what the oil pressure looks like.
One step at a time, I'm afraid. I believe the answer is going to be something simple but we'll get there.
I appreciate you guys, Jon.
I am hoping it's something simple and I feel silly because I have owned these old trucks for 35 years, but sometimes they stump a feller. I did remove the oil cannister supply line from the fitting on the block, I am going to go ahead and get a plug and see what the oil pressure looks like when I start the truck.
Someone has ran an oil line up to the head for better oiling so, my oil supply line goes into a brass T fitting.
Kevin
Last edited by kthomas; 05/07/20261:11 AM. Reason: Typo
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Well, I went ahead this afternoon, and got a plug and plugged off the brass T fitting where the filter cannister oil line connects, and when I started the truck, I noticed it did take a few seconds before the oil pressure gauge needle come off zero, and once it did, it went to 35 PSI. I didn't notice much cold start engine noise as before, so I took the truck out for a short drive and it's running great and carrying 30 PSI oil pressure.
I do want to mention that when inspected the supply line that I removed, it had some oil sludge in the end so I suspect that the filter also has sludge. I suppose it's possible that when did the oil change a while back, and with the driving I have done, it's broke some sludge loose.
Anyway, I did take Hotrod Lincoln (Jerry's), advice and bougth a pressure gauge, which is supposed to be here tomorrow, and I will reconnect the filter cannister oil supply line and attach the new pressure gauge and see what my actual oil pressure is.
I am hoping that I am getting to the bottom of my problem, thanks to all who have replied. I guess time will tell.
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
So as mentioned previously, I got an external pressure gauge as per Hotrod Lincoln's advice. I also blew out all the oil lines including the one that goes to the dash cluster gauge. I made sure both oil lines at the filter cannister were clear of any sludge, and I decided to go ahead and change the oil and man was it black. As mentioned, the old gentleman I bought the truck from hadn't changed oil in it in a very long time, so I suspect when I did my first oil change back in November or December, the new VR1 oil did some cleaning of the engine.
I connected the pressure gauge to the oil supply line that comes off the block and goes to the filter cannister, and tied it to the fender brace and had the wife observe when I started the engine after the oil change.
The oil pressure immediately came up and there was no cold start engine noise at all. I removed the external pressure gauge and re-connected the supply line to the oil filter cannister, installed a new WIX 51006 filter and hopefully, problem is solved.
I drove the truck into town and back and it ran flawlesly. Thanks to everyone for their help, including Hotrod Lincoln and Jon.
Good work- - - - -you approached the problem logically, and didn't make a bunch of changes all at once. Sometimes the "shotgun" approach creates more problems than it solves! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
