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Engine oil pressure question
Posted by: guthrie1068 ()
Date: August 26, 2019 04:42PM

My engine is having a couple of issues. First, I had 10w30 in it, and when I cold start it in summer time temps it would make some noise for the first 2-4 seconds until the oil pressure came up, then, after driving for a bit and the engine was up to temp it has a light knock only at idle. When cold right at start up the oil pressure was about 34 and at idle it was around 8-10. I changed the oil to 15w40, which raised the oil pressure at start to around 40, and no noise at start up, but once it is warm the knock is still there at idle when the oil pressure is in the low teens. As soon as the rpms raise and the oil pressure goes up the knock goes away. The shop manual says that the oil pump pressure regulator should regulate at 35psi. I'm kicking myself for not changing the oil pump when I had the pan off and could have done it then. I guess I am wondering, is the pump bad, or is the regulator bad or both? I will say that it runs quiet as a church mouse when it is off idle, no knocking at all. That makes me think it is a pressure issue, but I'm not even sure if that is true.

Chad Guthrie
Onondaga, MI
'63 convertible

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Re: Engine oil pressure question
Posted by: Lane66m ()
Date: August 26, 2019 04:55PM

Oil pump is in rear cover driven by distributedr shaft. No access through oil pan. Hopefully you made sure oil pick up was clear and pan wasn't bent up into the pickup.

Oil pressure changes with engine rpm and oil temperature. That is normal. 35 psi is normal pressure on an engine with good clearances. Could be your engine is wearing out and showing it in lower oil pressure at idle. My repaired (mostly rebuilt with replacement parts, excluding main bearings) has about 15 psi at idle, 35 when cruising, when hot. A new oil pump may help the situation, but the knock may be a symptom of worn main and rod bearings which is where oil pressure can be lost.

If you haven't done a compression test recently, this might be the time for it to check for significant loss of engine compression. Another indicator of a worn out engine.

Al Lane
Ellabell, GA 31308

1966 Monza Coupe, 110 hp, 4 Spd
1966 Monza More Door 110 hp, PG
1968 Camaro SS Coupe 350 CI 295+ hp PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
1947 Farmall A tractor 15 hp





Edited 1 time(s). Last edit at 08/26/2019 04:59PM by Lane66m.

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Re: Engine oil pressure question
Posted by: guthrie1068 ()
Date: August 26, 2019 05:14PM

Well, I guess I can stop kicking myself for not changing the pump when the pan was off, since it wasn't there. A little embarrassed that I didn't know where it was now... I did make sure that the pickup was clean, and the pan wasn't dented so I feel good about that. I had a feeling that I was going to hear the bad news, but was hoping that it would be something else. I'll do a compression test soon and see what I have. Thanks for the advice.

Chad Guthrie
Onondaga, MI
'63 convertible

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Re: Engine oil pressure question
Posted by: MattNall ()
Date: August 26, 2019 05:27PM

What ever you find... keep driving it! Even if a daily driver... may be years until things get worse..

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Engine oil pressure question
Posted by: squirrel ()
Date: August 26, 2019 05:33PM

The 63 I had a couple years ago had about 30 psi cold at driving rpm, and only a couple psi hot idling, maybe 20 hot at cruising rpm. It had a faint knock all the time.

I decided to go on a 5000 mile trip with it, and it did fine....of course, I took the oil pressure gage out of the car so I wouldn't worry so much, and popped it into neutral at stops so the light would go off smiling smiley

later I overhauled it, the bearings were well worn...better used bearings made the knock go away, and the oil light stayed off at hot idle in gear.

They will indeed to for quite a while with low pressure.

Jim Forbes.......63 Monza coupe......Sierra Vista, AZ


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Re: Engine oil pressure question
Posted by: Lane66m ()
Date: August 26, 2019 05:39PM

Matt is right the engine could last for years as long as you take care of it. Change oil/filter on schedule, allow engine to warm up before driving, no jack rabbit takeoff. Just be easy on the engine and have many years of use. But be proactive and start budgeting and saving for a engine rebuild if you are going to keep it for a long time. You are looking at $1500 to $6000 to do an engine repair/rebuild depending if you do it yourself or contract it out.

My engine in my More Door was about $1200, but I didn't split the case nor have the heads done. My engine for the Coupe is already at $4500, but heads are reworked to big valves by a forum member, crankshaft nitrided and machine shop work done, new cam, pistons, cylinders, rods and lots of new parts to put it together.

Al Lane
Ellabell, GA 31308

1966 Monza Coupe, 110 hp, 4 Spd
1966 Monza More Door 110 hp, PG
1968 Camaro SS Coupe 350 CI 295+ hp PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
1947 Farmall A tractor 15 hp


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Re: Engine oil pressure question
Posted by: guthrie1068 ()
Date: August 26, 2019 05:45PM

Thanks for the great advice! I'll do just that, start a fund now and drive it until I'm ready to fix it. I've said it before, but it's worth repeating. This forum is full of great and experienced people. I appreciate your help!

Chad Guthrie
Onondaga, MI
'63 convertible

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Re: Engine oil pressure question
Posted by: joelsplace ()
Date: August 26, 2019 06:47PM

Since you made some improvement with 15-40 why not try 20-50?
Turn the idle up a little if you can to get rid of the knock. if you can avoid the knock it will last a lot longer. Adjusting the pump clearance could help also.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Engine oil pressure question
Posted by: oldqmguy ()
Date: August 26, 2019 07:23PM

With my Custom Instrument Panel I now have a direct reading Oil Pressure meter and the Idiot Light Switch feeding the System.

I have about 40psi with the engine cold. Driving in 90 degree weather it reads around 20 psi.

At idle, on the pressure drops to between 7 and 8 psi!

I have the System programmed to show Oil Pressure when it drops below 10 psi.

This seems to be normal for a Corvair. The Idiot Light Switch for Corvairs is set for 5 psi! I am using 10-30 oil and the car runs well

Dale cool smiley

Dale E. Smiley CPBE
Life Member The Society of Broadcast Engineers
RETIRED Broadcast Engineer
CERTIFIED CORVAIR NUT
CORSA/Circle City Corvairs/Corvair Performance Group
Avon, Indiana
WB9SFF
1967 4-Door Monza PG!

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Re: Engine oil pressure question
Posted by: Lane66m ()
Date: August 26, 2019 07:29PM

Dale: He needs to know miles on your engine. To compare to his engine. My engine only has 720 miles following the repair I did. Never gets oil press light at idle when engine is hot.

Al Lane
Ellabell, GA 31308

1966 Monza Coupe, 110 hp, 4 Spd
1966 Monza More Door 110 hp, PG
1968 Camaro SS Coupe 350 CI 295+ hp PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
1947 Farmall A tractor 15 hp


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Re: Engine oil pressure question
Posted by: squirrel ()
Date: August 26, 2019 08:52PM

You can also fix the engine for a lot less than $1500 to $6000 if you are frugal and somewhat familiar with engines. The one I mentioned above...got the used bearings from a free engine, spent $80 on a gasket set, that's a lot less money than $1500.

Jim Forbes.......63 Monza coupe......Sierra Vista, AZ


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Re: Engine oil pressure question
Posted by: oldqmguy ()
Date: August 26, 2019 09:22PM

My current Corvair is a 1967 Monza with PG and a 110 engine.

I bought it in 2016 and have not done any major engine work. The seller told me that he was told by the person he got it from that it had been "overhauled" around 2000!

It starts well and runs good

The original Speedometer showed a little over 74,000 miles on the odometer.

It was the original Speedometer,but no one had any idea what it read when the "overhaul" was done. Nobody knows exactly what the overhaul was!

I repaired the electrical system, put in a new fuse block, changed all the lights (except headlights) to LED's, and had a new Custom Instrument Panel made by Dakota Digital. I set the new odometer to the same reading as the old one.

All this being said, I have no way to state how many miles are on this "rebuild!"

Now that the Fuel Pump has failed I am in the middle of putting in an electric one. Once I get that done I plan on driving it this fall and see if anything else fails!!

Dale winking smiley

Dale E. Smiley CPBE
Life Member The Society of Broadcast Engineers
RETIRED Broadcast Engineer
CERTIFIED CORVAIR NUT
CORSA/Circle City Corvairs/Corvair Performance Group
Avon, Indiana
WB9SFF
1967 4-Door Monza PG!

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Re: Engine oil pressure question
Posted by: playerpage ()
Date: August 27, 2019 07:34AM

Me and my inserted questions again--I have that knock when first starting the car on the left side. Basically it has been there ever since I tried to adjust the valves myself. So I need to try again, or is it as Matt says and the car is still drivable...?

My own oil pressure seems fine. As in the OP's case, the knock pretty much goes away once the car warms up

____________________________________________

Eric C. Player, Porterville, CA
Member: CORSA National, Central Coast CORSA, South Coast CORSA, and San Joaquin Valley Corvair Club
THEN: 1965 Monza 110 Canary Yellow
1967 Monza 140 Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo; nicknamed "Bluvair"

"It would not have helped if I had [taken notes], as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

------



Edited 1 time(s). Last edit at 08/27/2019 07:36AM by playerpage.

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Re: Engine oil pressure question
Posted by: 63vert ()
Date: August 27, 2019 10:09AM

I would recommend freshening up the oil pump. Your engine may be worn, but if you can recoup some lost pressure from a worn out oil pump.....it may help you get a few more years before an engine rebuild.

Rockingham, NC

1962 Greenbrier
65 110 4speed

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Re: Engine oil pressure question
Posted by: jjohnsonjo ()
Date: August 27, 2019 11:07AM

playerpage Wrote:
-------------------------------------------------------

> My own oil pressure seems fine. As in the OP's case, the knock pretty much goes away once the car warms up


I had one that went away many years ago, cracked piston skirt, fine after it warmed up

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Re: Engine oil pressure question
Posted by: guthrie1068 ()
Date: August 27, 2019 02:40PM

joelsplace Wrote:
-------------------------------------------------------
> Since you made some improvement with 15-40 why not try 20-50?
> Turn the idle up a little if you can to get rid of the knock. if you can avoid the knock it will last a lot longer. Adjusting the pump clearance could help also.


This is great advice, and I'll try to change the oil this weekend. Any tips on adjusting the pump clearance, I'm not sure what you mean? I did notice today that when I started it, it did rattle for a couple of seconds, which I thought had stopped after the last oil change. I'll keep driving it, check the compression this weekend, and put a plan together to address it over the winter, even if that is just pulling the pan and double checking the pick-up and screen. I never noticed it when I drove it before, but the idle was set really high then. I'm sure increasing the idle speed a little bit will help significantly, great advice and an easy adjustment to make.

Chad Guthrie
Onondaga, MI
'63 convertible

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Re: Engine oil pressure question
Posted by: joelsplace ()
Date: August 27, 2019 03:20PM

Pump end clearance is set with selective gaskets.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Engine oil pressure question
Posted by: steve57 ()
Date: August 27, 2019 03:42PM

I checked my oil pressure yesterday because of a flickering light when idling. Cold start about 40psi, hot idle 10psi, 2500 rpm 35psi. Put new pressure
sensor in, set idle a bit higher. This car has a Clark’s AC system on it and I think the idle setting was a little low when running it.

Steve
Bakersfield,Ca
69 monza 110,4 speed #4593

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Re: Engine oil pressure question
Posted by: 7004doorL ()
Date: August 27, 2019 04:37PM

IIRC The new oil pump gears should come with 3 gaskets of different
thicknesses in the box. The one that does not allow drag on the Gears
without being too loose should be the one.

Use Plastigage, or if no Plastigage, are you comfortable with removing and re inserting the Distributor? I use a large flat blade screwdriver to check the
new oil pump gears for drag by its drive slot under the distributor.

Mike 1960 4 Door.



Edited 1 time(s). Last edit at 08/27/2019 08:03PM by MattNall.

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Re: Engine oil pressure question
Posted by: Wagon Master ()
Date: August 27, 2019 04:55PM

7004doorL, Are you on the 69 more door registry?

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