low oil pressure when hot

[73azbronco]

Rotella is just a really good oil.

 

[blubuckaroo]

Do you feel it gives you a little more pressure?

Todd Z.

Back when 10W-40 came out, I tried running it in my '70 Chevelle SS 396. It would consume the stuff and would make lifter noise in hot weather. Valvoline SAE 30 Racing Oil didn't have those issues.
I think oil for these old engines should be selected for the climate and service they will be used in. Cold weather, and frequent cold starts needs a lighter oil like 10W-40. Summer and long distance gets 15W-40 or SAE 30.

I guess what I'm trying to say is that 10W-30 isn't just SAE 30 that starts out thin and gets thick when hot. It starts out thin and gets even thinner when hot. It just maintains it's lubrication properties across a broader heat range. This does nothing to help oil pressure or oil consumption.

Back to your question about oil pressure though...
Yes, when I change from 10W-40 to 15W-40 in the spring, I can see a higher oil pressure.

 

[toddz69]

Back when 10W-40 came out, I tried running it in my '70 Chevelle SS 396. It would consume the stuff and would make lifter noise in hot weather. Valvoline SAE 30 Racing Oil didn't have those issues.
I think oil for these old engines should be selected for the climate and service they will be used in. Cold weather, and frequent cold starts needs a lighter oil like 10W-40. Summer and long distance gets 15W-40 or SAE 30.

I guess what I'm trying to say is that 10W-30 isn't just SAE 30 that starts out thin and gets thick when hot. It starts out thin and gets even thinner when hot. It just maintains it's lubrication properties across a broader heat range. This does nothing to help oil pressure or oil consumption.

Back to your question about oil pressure though...
Yes, when I change from 10W-40 to 15W-40 in the spring, I can see a higher oil pressure.

Thanks! I was just curious. My engine is a '91 5.0 and it's spec'd at 10W-30. It has a lot of miles on it and quite a few years ago I ran 20W-50 for a period of time and then switched back to 10W-30 a few years ago. Since the engine is old, I now have about 20 psi at hot idle and 45'ish psi at cruise. I run the Rotella 15W-40 in my Super Duty and it would be very convenient to run it in the Bronco as well. Maybe I'll try it for the next oil change.

Todd Z.

 

[blubuckaroo]

Thanks! I was just curious. My engine is a '91 5.0 and it's spec'd at 10W-30. It has a lot of miles on it and quite a few years ago I ran 20W-50 for a period of time and then switched back to 10W-30 a few years ago. Since the engine is old, I now have about 20 psi at hot idle and 45'ish psi at cruise. I run the Rotella 15W-40 in my Super Duty and it would be very convenient to run it in the Bronco as well. Maybe I'll try it for the next oil change.

Todd Z.

Why not? Just make sure the oil has a S rating for gasoline engines. Most of them do.

 

[jeff_gates]

To circle back, I pulled the oil pan and cleaned the pickup. a tiny bit of metal and some RTV. I installed a Melling HV83, the hardest part was reconnection the dipstick tube. I did put in 10w-40 and now at idle I get about 16 lbs on the gauge.

Thanks,
Jeff

 

[Lawndart]

I am late to the party. Mine was similar when I got it. I installed a mechanical oil pressure gauge near the other sender. I was getting 10psi warm (electrical gauge reading 0).
When I had the pan off for timing chain and general gasket clean-up, I installed a new Melling pump. That fixed it.

 

[Pa PITT]

LOTS OF GOOD ANSWERS in this post.
I have 3 farm trucks that have pressure about the same .
I do like Rottella oil .& RUN a lot of 15w40w.
... But in 2 of mine that pressure drops to maybe 10lb . I swapped over to straight 40 w. & QUAKER STATE Because I don't like Pennzoil. . yES I do think wix Filters are the best. & Fram is the total worst . FL1A is also very good .
I'm not above putting in some STP . & I'VE RAN A LOT OF LUCUS . .
AN ALTERNATIVE TO STP is Motor Honey made by CASITE . OR another name for itnow id Radiator Speciality Produces. Yellow can.
.....