oil pressure issue
Thread Starter
Burning Brakes
Joined: Dec 2003
Posts: 1,149
Likes: 153
oil pressure issue
My 69(427)usually has an oil pressure of 34lbs at idle(900rpm)when warm(15-40 wt oil)and around 50lbs at3000rpm with a stock oil pump.Today it would only go to 36(or so)lbs at cruising speed(3000rpm).When I came to a stop it went down to about 26lbs,then drove a little further and she stayed at 34lbs when I stopped.The engine is pretty fresh with maybe 4 or 5000 miles so I'm pretty sure it's not the bearings.I've just changed the oil and filter(K&N) and wondering if this could be a bad filter,I've never had a bad filter so I don't know if it could cause this type of problem.The other thing that comes to mind is a failing oil pump,the pump is older as the one that was put in at the time of the rebuild read very low so I put the old one back on(maybe 20 or25000 miles on it.I would appreciate any insight or suggestions.Thank you
Melting Slicks
Joined: Mar 2005
Posts: 2,093
Likes: 297
From: Midlothian VA
My 69(427)usually has an oil pressure of 34lbs at idle(900rpm)when warm(15-40 wt oil)and around 50lbs at3000rpm with a stock oil pump.Today it would only go to 36(or so)lbs at cruising speed(3000rpm).When I came to a stop it went down to about 26lbs,then drove a little further and she stayed at 34lbs when I stopped.The engine is pretty fresh with maybe 4 or 5000 miles so I'm pretty sure it's not the bearings.I've just changed the oil and filter(K&N) and wondering if this could be a bad filter,I've never had a bad filter so I don't know if it could cause this type of problem.The other thing that comes to mind is a failing oil pump,the pump is older as the one that was put in at the time of the rebuild read very low so I put the old one back on(maybe 20 or25000 miles on it.I would appreciate any insight or suggestions.Thank you
Safety Car
Joined: Apr 2006
Posts: 4,057
Likes: 421
From: BC
A problem I had with my 69 L36 was that the oil pressure gauge was slow to respond and registered low at times. I removed the line from the back of the gauge and the fitting above the filter and blew the line out with compressed air at the gauge fitting. That cleared it up but it could also be a sticking gauge. I would look into both before considering a motor or oil pump problem as you said the pressure came back up.
Drifting
Joined: Sep 2014
Posts: 1,430
Likes: 59
From: Long beach NY
St. Jude Donor '15-'16, '18
Had issue like that awhile ago, turned out i was quart low, hope you get it figured out.
Thanks again fir help few weeks ago.
If you were on way to Captree when oil issue popped up, all lots were full all way to water.
Cars lined up past entrance pulling in.
Greg
Thanks again fir help few weeks ago.
If you were on way to Captree when oil issue popped up, all lots were full all way to water.
Cars lined up past entrance pulling in.
Greg
Last edited by Calo69; Apr 19, 2016 at 12:13 PM.
Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
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Could be a clogged oil line to the gauge. Another thread here reported that issue. Has the outide air temp changed dramaticlly or is the car running hotter. Either could thin the oil if your just used to the cold temps of the winter
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
First thing I would do is change the filter to see if the oil psi changes. That would be an easy and cheap test...and you lose nothing in the process. If nothing changes, you can still use the other filter later. That will eliminate the filter as the 'problem'; but you still have the problem. (It would be best to stick another psi gauge in the system when you change the filter out. You will be testing two things, but the extra gauge keeps the testing 'clean', as you can use the dash gauge to evaluate change due to filter swap.)
It could also be that the K&N filter you installed has better filtering capabilities, but causes more resistance to oil flow (because of finer filter path) and it drops more pressure across it. To assess this issue, you should replace your present filter with an exact duplicate filter (K&N).
If the psi goes back up with filter swap, the filter you have now is junk (likely leaking overpressure dump). Take it back for a refund or pitch it.
It could also be that the K&N filter you installed has better filtering capabilities, but causes more resistance to oil flow (because of finer filter path) and it drops more pressure across it. To assess this issue, you should replace your present filter with an exact duplicate filter (K&N).
If the psi goes back up with filter swap, the filter you have now is junk (likely leaking overpressure dump). Take it back for a refund or pitch it.
Last edited by 7T1vette; Apr 20, 2016 at 03:08 AM.
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Instructor
Joined: Apr 2016
Posts: 104
Likes: 7
From: Denver Colorado
If the oil filter was plugged solid you would still have full oil pressure because the filter bypass valve would open. I still suspect the nylon tubing going to the gauge has a kink in it because mine did the exact same thing several weeks ago. By pulling the gauges foreword and re-positioning the line my gauge read normal again.
Thread Starter
Burning Brakes
Joined: Dec 2003
Posts: 1,149
Likes: 153
7T1vette is the winner.I changed the K&N and put on an AC filter and all seems to be good.I've used K& N before and never had any issues.I probably ditched the receipt so there goes $13 down the tubes,but on the bright side,a cheap and easy fix.Thank you for all the good responses,I'm sure I'll probably be needing them in the future. Mike