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06-15-2015, 09:11 PM | #1 |
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Oil pressure is really low
I have noticed over the last few months that my pressure has slowly went down. Around 8 months ago, it was at 30 PSI and then slowly went to 25PSi and now it is at 16PSI. The engine gets extremely hot but the temp gauge shows it is at least 185 degrees
I have a feeling that the oil pump is going bad Any ideas?
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1971 GMC Sierra 1959 GMC 100 Last edited by SCHRUMGMC; 06-15-2015 at 09:32 PM. |
06-16-2015, 01:55 PM | #2 |
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Re: Oil pressure is really low
30 is normal when cold and running over 1500 RPM. 15 is not bad at idle. This assumes your gauge is accurate. Constant low means worn oil pump OR old main and rod bearings. Have you ever ran the compression on the engine? That is where I would start as a general indication of the age/condition. Also, since it has set for awhile I would get a few miles on it before tearing into any thing so things can tighten up. My 64 Chevelle had sat for years with occasional use. When I started driving it daily, especially at higher RPM, it smoked and leaked like crazy. After about two weeks the seals, rings and valves tightened up and it went strong for another 60K. What weight oil are us using?
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1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project |
06-16-2015, 02:14 PM | #3 |
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Re: Oil pressure is really low
What oil are you using in it. If you put a high detergent oil in it the detergent may have loosed up some of the crud in the engine and it may be plugging the pickup screen now.
It might be worth the price of a pan gasket to drop the pan and clean it and the screen on the oil pickup out and then pull a bearing cap or two and see what the bearings look like.
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Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around. |
06-16-2015, 05:32 PM | #4 |
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Re: Oil pressure is really low
I was always told as long as you have 10lbs of pressure for every 1K of RPM's life is good.
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06-16-2015, 06:03 PM | #5 |
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Re: Oil pressure is really low
The pressure moves very high when the truck is accelerating. Could be the oil type that is being used, because it hasn't been changed in 3/4 years but it hasn't really gone anywhere
Alright, the temp gauge reads about 180 degrees but the engine is so damn hot that it is unbelievable. I have replaced the thermostat, the radiator is fine. The water pump is moving the fluid inside. So maybe it is just my imagination, it is venting excessively though
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06-17-2015, 12:27 AM | #6 |
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Re: Oil pressure is really low
Pressure rising as you increase rpm is normal. 15# at idle is acceptable. Spend $20 on a cheap aftermarket temp gauge, your gauge might be reading way off, especially if it is the original stock. Mine started running hot and that is what I found out, it was the gauge. In you case if its spewing but only reading 180 something is wrong. What temp t stat are you running, 185 is standard? What pressure cap, 5 # is all you need. If someone put on a higher pressure cap it can cause problems. You might want to get an inexpensive probe type thermostat, run it up to what you think is hot, pull the cap a see what the temperature is. Are you using just water or coolant mix? Does it have a shroud, if the fan is not close to the radiator, might not be pulling enough air thru it.
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1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project |
06-17-2015, 12:37 AM | #7 | |
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Re: Oil pressure is really low
Quote:
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06-17-2015, 12:41 PM | #8 |
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Re: Oil pressure is really low
Bipass the heater core and check the hoses to it for blockage, that could be your part of your over heating issue. Sooty plugs is carb jetting issue, choke is staying partially shut making the mixture too rich or timing (fuel not getting completely burned). Yes I know you got a new carb, but that does not mean it was tuned for your engine. Backfiring thru carb AND exhaust means your timing is jumping from advance (carb) to retarded (exhaust). This will also affect the engine temp., retarded timing causes temperature to got up.
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1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project |
06-17-2015, 01:35 PM | #9 | |
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Re: Oil pressure is really low
Quote:
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06-18-2015, 02:03 AM | #10 |
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Re: Oil pressure is really low
I meant to ask, since that I am using the Ballast resistor on the firewall and a Coil made for it. However, I am using a petronix ignition kit. Do I need to buy an internal resistor coil or just leave it the way it is? It's been doing fine until now, since it is sputtering again with no power
Since i got rid of the points wire, I guess that put the ballast resistor pretty much useless. The coil is still an old style coil meaning its used for the ballast resistor. Do I need to buy an internal coil or is it fine? I know that i will need to buy some more plugs due to the old carb causing most of the problems It was running so good last week and now it will hardly run and I tried going up a small hill and it wouldn't even budge...Hmmmm
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1971 GMC Sierra 1959 GMC 100 Last edited by SCHRUMGMC; 06-18-2015 at 02:12 AM. |
06-18-2015, 12:10 PM | #11 |
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Re: Oil pressure is really low
What does the Pertronics installation paperwork or website say to use? Should also have info on the ballast?? I know nothing about Pertronics. If you have factory windshield wipers they are powered off of the side of the resistor (ballast) that comes from the ignition switch.
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1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project |
06-18-2015, 12:35 PM | #12 |
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Re: Oil pressure is really low
It never said anything about that
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06-18-2015, 02:18 PM | #13 |
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Re: Oil pressure is really low
Go back and read your instruction sheet for that particular ignition and pay very close attention to the "wiring instructions. Especially part 2 A. The part that says that "we recommend".
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Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around. |
06-18-2015, 10:33 PM | #14 |
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Re: Oil pressure is really low
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1971 GMC Sierra 1959 GMC 100 |
06-19-2015, 12:24 PM | #15 |
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Re: Oil pressure is really low
I looked at this one, seems to have more information and shows the wiring for the ballast.
http://www.pertronix.com/docs/instru...heets/1141.pdf It appears that you can use a stock coil, assuming it is in good shape and meets the requirements. Here is an article on their site for testing your coil to see if it will work. http://www.pertronix.com/support/tips/default.aspx#a2 They also have a troubleshooting section that discusses reasons for poor engine performance, troubleshooting, and fixes.
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1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project |
06-19-2015, 02:00 PM | #16 |
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Re: Oil pressure is really low
Yeah, I bet it is probably the plugs and last time I checked they ere black
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06-19-2015, 08:40 PM | #17 |
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Re: Oil pressure is really low
Oil temp sounds like it is high.
Hot, hot oil will thin out and give low pressure readings. Here's what I recommend: 1. take the vacuum hose off the distributor and retime the engine to 0 degrees. That will be a bit retarded, but should eliminate any unheard pinging that it may have, driving up the temperature due to cheap gas, improper timing etc. drive it a little, and see if the temp goes down. If not, return to your settings. 2 One of the fastest ways to make an engine hot is to lean it out. Check your fuel filter, reset your floats, and make sure your fuel pump is pumping enough fuel. 3. If all that checks out, get a meat thermometer, or a digital hand held thermometer, and point or put the thermometer at the upper hose, lower hose, radiator tanks, oil pan, and exhaust manifold. Oil should never get to 400 degrees, and with a 180 water temp, you should see about 220 oil temp. 180 degree water should leave the engine in the upper hose at about 180-190 degrees, and re-enter the engine at the bottom hose around 140-160. Rev up the engine, and look at the lower radiator hose. If the spring is no good or missing in the lower hose, it will collapse the hose if you rev it, shutting off the cool water. 4. you might have an exhaust restriction. If you have dual pipes without an X pipe or H pipe, feel the tail pipes. they should be equally hot, and then get a stiff piece of paper, and hold the paper at the end of the pipe where the exhaust comes out. The paper should flutter at each pipe the same as the other. If you have an h pipe or x pipe, is one tail pipe without any exhaust? 5. Check your heat riser if you still have it. If that is stuck, use some W-40 and soak it overnight and use a small hammer, gently tap it back and forth. Then wire it open. 6. You said the oil is old. Old oil with low time only gains an acidic quality. What it will do is begin to erode the bearings and other soft metals in the engine. 7. The best thing to do is run it weekly, get it up to temperature and get it hot enough to make any condensation evaporate. 8. Years ago, I could not get my 57 chevy truck to cool in 115 degree Phoenix heat. What I did was add an oil cooler and an aluminum radiator. With the cooler, the radiator wasn't necessary, but I was driving it 50 miles a day to work and back, and it was just insurance. Good luck with your troubleshooting. P,S. Backfiring through the carb usually means that an intake valve is hanging open when it should be closed. Try adjusting the valves to see if it will go away. If your valves are out of adjustment, you could be getting the thing hot by not opening the exhaust valves far enough, getting the exhaust out. BTW, the exhaust manifolds should be the same temp front to back, and for V8, side to side. Also, make sure the coil wire from the key is positive, and the pertronix wire goes to negative. You need the resistor sometimes. For electronic ignition you might clip a jumper across the ballast resistor for a couple minutes and see if things change. If the coil is a problem, borrow one, or buy one. If it doesn't fix the problem, take it back. Just don't scratch it and mess it up. Usually, you can't take back opened electrical items. They think you let the smoke out of the part. I have MSD ignition in my 57, and I use the ballast resistor with the resistor jumpered permanently as a terminal board to run things when the ignition is on. Sort of looks stock sitting up there on the firewall, but gotta get rid of it soon though.
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http://http://67-72chevytrucks.com/v...d.php?t=489721 Last edited by Coupeguy2001; 06-19-2015 at 09:03 PM. |
06-19-2015, 09:47 PM | #18 |
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Re: Oil pressure is really low
Thank you for the information man. I checked the temp with a radiator thermeter or something in that nature. It was around 180 I believe, i'll check it again. It spits and sputters now so its hard to drive...it will idle though
I'll check out things when I get time
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06-20-2015, 10:16 PM | #19 |
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Re: Oil pressure is really low
I think I've found out why it was so hot. I adjusted the timing and the oil pressure went up a little, and the engine didn't get as hot
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