View Full Version : 62 Eureka Hearse low oil pressure

Ricky Jones
11-04-2014, 03:22 AM
Aloha from Honolulu,

My 62 Eureka Hearse 390 engine was rebuilt about a year ago.
Always had low oil pressure. Cold idle is 27PSI and max 29. Hot is idle 6 PSI and max on the freeway at any speed 21 PSI. Even with 60W and Lucus only about 1 or 2 PSI better.

Oil pump also rebuilt and even pulled the oil pan and put a couple small washers with the new spring. Did not help.

My 59 Coupe De VIlle and 59 Series 62 Convertable both those 390s are rebuilt and have 30PSI cold idle and 32max and hot idle 20PSI and max 28PSI on freeway. They both have a couple washers on oil pump pressure release spring (shim).

Any idea what I can do to up the presure?

Peter Grave
11-04-2014, 11:11 AM
When engine rebuilt were camshaft bearings replaced? If not this can be the problem. Many times rebuilders skip this and there it goes.

Richard Vyse
11-04-2014, 12:07 PM
Is the guage faulty? My Corvette had high oil pressure then replaced the sensor and guage, back to normal.

John ED Renstrom
11-04-2014, 12:24 PM
it does sound like a internal problem. one would have to do research in the manual on. maybe a better place to find help would be on the CLC web site. a lot of gear heads there and with thee numbers some one will have some advice. if it a common overlooked thing it gets talked about thee.

Ricky Jones
11-04-2014, 01:10 PM
The cam and cam bearings were replaced along with main bearings pistons everything. Wonder how to tell if something internal Peter?

Thanks Richard the guage is a good electronic one under dash unit I use on all three cars.
John what is the CLC? What is the web address? Thanks

I suspect the oil pump. Can't get a new one for a 1962 390 engine as far as I know. Does anyone know the correct hot and cold oil pressure.?

I plan to pull the oil pan and check the pump. Any advice on what to look for
signs of wear. It has new gears and spring and looked fine when I saw it at rebuild.
This is a daily driver I got to fix this or engine won't last.
Thank you

Daniel Scully
11-04-2014, 01:38 PM
Thanks Richard the guage is a good electronic one under dash unit I use on all three cars.

I would attach a mechanical oil pressure gauge first to double chk the electronic one before doing anything else.:my2cents:

Paul Steinberg
11-04-2014, 03:59 PM
By increasing the weight of the oil, you are actually doing harm to the bearings, since the heavier oil can't lubricate as well as the lighter weigh oils. If you are using a 60 weight oil, then I believe that you have created your own problem, and might have damaged the bearings. The best thing to do now, is to drain a small amount of oil, and send it out for testing. The test will tell you if there is bearing material in the oil, and if there is, then that means that the bearings are wearing excessively. Rebuilt engines are typically broken in using 10W-30 oil, and it should be changed at 500 miles, and again at 1000 miles. After that you can follow the manufacturers recommended oil changes. In the 1950's and the early 1960's, the oil change recommendations were 2000 / 2500 miles, depending on the car manufacturer. 3000 mile and higher oil changes didn't come about till the later 1960's, when they introduced additional ZDDP to compensate for the breakdown of the oils. Modern engines have such close tolerances, that some of them require 0W-20 Synthetic oils, and if you use anything else, you will do engine damage. You are always best to read and follow the recommendations of the automobile manufacturer, regardless of when the car was manufactured. Todays oils are far superior to what was available 50 years ago, but the weight of the oils is still important. Once you start modifying oil pumps, etc. beyond what is normal, you increase the chances of doing damage, that you might not realize for a number of miles, when you start to experience failures.

Peter Grave
11-04-2014, 04:59 PM
Pauls point on the oil is well taken you CAN do damage with heavy oil not the answer. CLC= Cadillac Lasalle Club. Definitly check pressure with mechanical guage electric ones are known to be flakey. Check Kanter Auto Boonton NJ for a new pump. These are good engines not known for issues. I personally am not in favor of rebuilding engines in collector vehicles unless there is a problem many times more harm than good is done. My motto is if it runs good, no bad noises, no smoke, leave it alone. Rebuilding as part of the restoration is not always wise when vehicle is running OK.

Paul Steinberg
11-04-2014, 06:25 PM
If you have smoke, and low compression, then you might have stuck rings. Quick, easy, and inexpensive fix is to put a can of Seafoam into the oil, and drive the car. Change oil and filter at 3 - 400 miles, and refill with a good grade of detergent oil, and install a quality filter, such as Wix, and add another can of Seafoam. Within a 1000 miles, you should see some improvement in the reduction of the oil burning. If you don't, then it might be time to consider an engine rebuild. This works best on engines in the 25,000 - 50,000 mile range. If you don't drive your classic very often, then the Seafoam treatment is a must.
Seafoam also makes an automatic transmission conditioner, and it also works great to correct harsh shifting. It will not help with slipping transmissions, since that is a result of worn bands and clutches.
If you have an engine that leaks oil, don't use anything that claims to condition and swell the seals, because once you use that stuff, it will briefly seal the leaks by swelling the seals, however, shortly thereafter, they will shrink and the leak will be back, but it will be much worse than before, because the seals shrink up even more than they originally were. Some automotive chemicals are good, but the majority of them are just snake oil in a can, and rarely if ever, do they fix the problem. They might mask the problem for a while, and when the problem comes back, it is much worse than before.

Ricky Jones
11-05-2014, 01:52 AM
Good advice ion the oil. Thank you. I will put 10/40W back in it. I guess this is a collector car yes but for me has always been a daily driver I use for work to carry equipment. Engine had bad knocking so had it fully rebuilt. After rebuild (about a year ago) did use 10/40W oil and it always had low oil pressure from the beginning. Thats why I mistakenly started using 60W oil.

Ive always have a mechanical oil pressure guage under the hood as I have a oil primer system to send oil in when you turn key before you start. No dry starts. That guage reads same as the under dash electronic one.

Kantor has exchange only rebuilt oil pumps no new ones. The same rebuild kit they use is what I gave the machine shop to use to rebuild mine.

My two other Cadillacs with 390s (59 Coupe De Ville & 59 Series 62 convertible with 1962 390 engine) both have only a little better oil pressure as I mentioned in earlier post. I did not really think about this until after rebuild I put the under dash gauges and could see the pressure while driving and also heard about the 10lb PSI per 1,000 RPM rule from someone. Im on the freeway at 55 MPH and 2,300RPM and only 21PSI !
Be interested to hear what kind of oil pressure you guys are getting.
Mahalo for all the input.

Paul Steinberg
11-05-2014, 09:17 AM
Use 10W30 oil, and you should be fine at 21 PSI oil pressure. It is an engine, and as long as it has oil pressure that is sufficient to keep the valve lifters filled, and the bearings lubricated, you will have no problems.

John ED Renstrom
11-05-2014, 12:05 PM
you stop to this that there might be a bad check valve in that oil priming system. block it off of on both ends and see what you read. 9 time out of ten the problem is something we have added to the car. that is unnecessary for operation

Peter Grave
11-05-2014, 12:15 PM
Last comment on this remember oil pressure is not a measure of oil flow (volume) if volume is sufficent all is well. I have had V/8 Packards since the dawn of time and they have very fussy lifters and oil pump issues. I have used Castrol GTX 20-50 oil in them with great success and would reccomend you try same in your coach. Good Luck!!!

Ricky Jones
11-06-2014, 09:41 PM
Check valve to oil primer tank is OK.

I think that these 50 year old oil pumps are just worn. As in the housing case the pumping gears ride in and the new gears in the rebuild kit wont fix that.

Wonder what you guys get for oil pressure.

Thanks again for the advice.

Paul Steinberg
11-06-2014, 11:37 PM
If the pump housing was worn, you wouldn't have any volume or pressure. You have plenty of pressure, and there is no way to measure the volume, except to know that if there is no volume, there is no pressure. You are obsessing about something that you can't change, and even if you could change it, it still wouldn't make your engine perform any better, or last any longer. According to the 1963 Cadillac Shop Manual, the idle pressure should be 10 PSI (average), and the pressure at 30 MPH is 30-35 PSI (minimum). These figures are based on a new engine, using the type of oil that was available in 1963. Fifty years later, the oils have changed, and it is unrealistic to expect the same performance from the modern technology oils that are being produced today. The one thing that we don't know, is what if any damage that you have done to the engine by using 60 weight oil in it.

Ricky Jones
11-07-2014, 03:08 AM
"According to the 1963 Cadillac Shop Manual, the idle pressure should be 10 PSI (average), and the pressure at 30 MPH is 30-35 PSI (minimum)"

Thanks for the specs Paul. When my engine was recently rebuilt and before using the 60W oil I was only getting about 21PSI at 30 MPH. No where near the 30-35 PSI (minimum) spec so yes I am concerned. And about the same 21PSI on the freeway too.

Reading about oil pumps I found this:
"The clearances inside the pump between the gears and between the gears, housing and cover have the most influence on oil pump performance. The tighter the internal clearances, the more efficient the pump and the more oil it can move. A worn pump or one with sloppy clearances will not work as efficiently resulting in low oil pressure and less oil flow."

After spending thousands to pull engine and rebuild it I don't want to do it again soon so I would at least like to run it on the 30-35PSI minimum spec.

Tom Hoczyk
11-07-2014, 07:48 AM
My '54 Eureka engine was totally rebuilt in the late '90's. Even from day one the oil pressure was low, even with a brand new oil pump. The car has been on numerous 200 mile trips since that time and it has never missed a beat. The points about the heavy oil are on the mark. Since my car only goes out in the summer, I've been using 15-40 Rotella-T and it has never given me a problem. In your case, if it runs well, I wouldn't worry too much about it.

Peter Grave
11-07-2014, 10:40 AM
I think perhaps we are missing the fact hat oils have changed and with many new additives for lower friction (read that better fuel mileage) I think there is a good chance this may account for lower pressure. If you are worried take an oil sample and go to a commercial diesel engine repair facility they can have the oil analyized for condition and particulates this will tell you if any damage is happening. My personal opinion is you are worrying needlessly.

Dave Simon
11-29-2014, 10:46 AM
On the subject of 0w20 synthetic in newer cars, I got in a debate with my Honda dealer about the 0w20 semi-synthetic the owner's manual calls for. There are only 3 countries in the whole world where Honda calls for 0w20 oil, and it has more to do with CAFE regulations than engine health. I would contend that 5w20 "conventional" is likely semi-synthetic anyway, or it wouldn't meet the specs to get the API sunburst rating, or meet SN specs.

Enough on that subject...with older cars, I would really want to attach a mechanical pressure gauge before I worried too much about an oil pressure issue.

Mike Stevens
12-01-2014, 08:59 PM
for starters I know the 63 and 61 390s are not the same engines. But my rebuilt 390 carries about 23 psi at road speed. Whatever the speed. At idle it drops to about 14 psi. I have put a mechanical pressure gauge on it to see the numbers while i drive. My coach came an idiot light for the oil warning system. I have always thought those lights only lit up by the time you had engine damage. So I depend on the gauge. My car has been on several 1000 mile plus trips. No problems with oil ever. I use 10W30 oil year round. My car rarely goes out into Ohio winters.

Ricky Jones
12-02-2014, 02:55 AM
I removed the oil pan again and put in a rebuilt oil pump. I cleaned out the pick up with solvent and compressed air. Put in 10W 40W and now get a little better pressure. Thicker oil is no solution. Thanks for advice on oil Paul.
Hot 10PSI idle and 26PSI on the freeway.

By the way. Putting in shims to stiffen the bypass relief spring will get you
100PSI cold which you dont want and then the same low oil pressure hot that you had before. At least that was my experience. Removed this pan soo many times.

And yes I do have a mechanical oil pressure gauge under the hood.
Reason I have been concerned with oil pressure is after thousands to remove, get machined, rebuilt and reinstall I dont want to do it again for some time.
Oil flow for cooling bearings and pressure to keep them from contacting the crank is important especially with a 7,300lb Hearse driving up the hill where I live on this little island. Thats alot of load.
This is a daily drive too.
Hopefully 26PSI will be good enough.
Mahalo for all the input.
Ricky Jones

Peter Grave
12-02-2014, 10:42 AM
OK now we are getting somewhere. I did not realize the hill issue. You may or may not be aware most cop cars have external engine oil coolers. I am not sure where you would tap in on the 62 engine but I think an external cooler would do much to protect your investment. Back in the day I had a good customer who pulled a a LARGE travel trailer with his Cadllac Convertible. He had us install oil temp guages on both the trans and engine after watching activity similar to the stock market we installed external coolers on both engine and trans. Then the customer got creative he took two windshield washer pumps installed reservoirs with water then a copper tubeing set up with holes drilled in it to spray water on the coolers.On a steep hill he would hit this set up and oil temps dropped 20 degrees. Just a thought for your issue.

Ricky Jones
12-07-2014, 02:00 PM
Thanks Peter!
Yes I have considered an external oil cooler. We dont live so far
up the hill however.
I think they have cooler that taps in at oil filter at block with adapter installed.

In hot Thailand my 64 Fiat with aftermarket underdash AC would get hot.
Had simular rigged windshield wiper pump that could spray water onto radiator and did temporarily lower temp in a pinch.
Not OEM probabely would have been better fix the heat up issue

Wonder how much oil cooler lowers them temp on daily hot driving?

Thanks again