low oil pressure
Thread Starter
Racer
Joined: Dec 2004
Posts: 336
Likes: 0
From: crystal lake Il.
low oil pressure
I have a 383, 2 years old with about 10000 miles on it. It runs real good. When new at startup I had 75 to 80#`s of pressure then it would go to 55 to 60. Last year it seemed to go down slightly but steadily. Now at startup I have 40# and it goes down to 20 at cruise and 15 at idle. I have a high volume oil pump and I`ve used different oil weights. Right now I have rotella t 5/40 full synthetic. I live in N. Il. so it is cold. Any ideas why such low pressure, how concerned should I be.
Instructor
Joined: Aug 2003
Posts: 104
Likes: 0
From: Newfane NY
To Keep it simple, try a new oil pressure sending unit.
BUT!!! If you can, place a mechanical Gage in that port to get an accurate reading.
You can buy a Gage and install the adapter and check without installing as a permanent fixture in the car and verify the oil pressure.
If the pressure is ok by changing the sender, Job is done
If pressure is good with mechanical gage, and still bad by sending unit, electrical troubleshooting begins.
Keep us posted!!!
BUT!!! If you can, place a mechanical Gage in that port to get an accurate reading.
You can buy a Gage and install the adapter and check without installing as a permanent fixture in the car and verify the oil pressure.
If the pressure is ok by changing the sender, Job is done
If pressure is good with mechanical gage, and still bad by sending unit, electrical troubleshooting begins.
Keep us posted!!!
Thread Starter
Racer
Joined: Dec 2004
Posts: 336
Likes: 0
From: crystal lake Il.
I installed a new sender a couple of days ago. The old one was erratic and bouncing around. They both read the same low pressure. I needed a new sender beause the new one is not erratic but it is not my problem.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
At least, it's time to check out the condition of a couple of crank bearings. If all is good, check the pump & regulator spring while you have the pan off. Hopefully, it is just a sender/guage problem; if it turns out to be bearing wear, it's good to catch it before the engine fails.
Drifting
Joined: Apr 2008
Posts: 1,540
Likes: 51
From: Lexington Park Maryland
Before you drop the oil pan I'd do a quick oil change and pour some of the used oil through a coffee filter to check if there are any metal shavings in it. Might want to cut the filter in half as well. It sounds like a bearing may be going bad. Just my 2cents..............
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
No....because the surface of the bearings is not magnetic. If your engine is wearing hard steel parts, it is in even more trouble. You can drain the oil and stir it up (hard particles sink to the bottom pretty quickly), then put some on a glass slide or in a thin bottle. Shine a strong light through it and see if there are any reflective particles in the oil. If so, you [likely] have a problem and need to check those bearings.
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Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
If you are really concerned send an oil sample to a oil lab and they can tell you what exactly has worn, of anything. Around 20 bucks.
Also the oil pump relief could be failing causing a lower indicated pressure.
Also the oil pump relief could be failing causing a lower indicated pressure.
Thread Starter
Racer
Joined: Dec 2004
Posts: 336
Likes: 0
From: crystal lake Il.
After changing the oil with 15/40 ci4 I now have 15-20# at idle and 40-45 at 2500 rpm. The biggest problem may have been the way the sender was installed. When the 383 went in the hole above the oil filter appears sealed . The sender I had didn`t fit near the distributor. So my friend aka bubba put in a straight adapter then a 90 then a an6 90 then a 18" piece of hose then a 90 then the sender. I removed all that and installed the proper sender.