Oil pressure drop after addition of OEM Oil Cooler?

gooffeyguy said:

Many specialized aftermarket pans made for road racing or drag racing have baffles located at different places (depending if you corner or are going straight with a lot of Gs) to help keep oil around the oil pickup tube in these situations. Kind of like how a fuel tank has a reservoir area around the basket or fuel pump sock to keep fuel in that area.

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there used to be a company that made one for it, well a baffle for the stock pan. but they discontinued it. I had the pan off and was thinking of installing one. emailed them why it was out of stock everywhere. they basically said it didn't work.


shame.

that's weird about the listing. that just pops up when you google ls oil cooler bypass valve or something like that. I don't honestly know if it's correct or not. I did change hoses once because they all leak after a while which is probably what Dorman means by upgrade. maybe they learned how to use oil proof hoses and crimp them right so they don't leak after a few years like all the oem gm lines do?

@j91z28d1 that oil cooler bypass you linked earlier looks just like the oil filter bypass that's listed on RockAuto for my 2001 5.3l Yukon

A different part # though

interesting. my 2011 yukon under shows the oil pressure relief valve for the afm stuff that screws inside the oil pan. shows the same type valve under the oil filter bypass valve and oil pressure relief valve. they look the same but different brands listed under each.

if I remember right there's not really a oil filter bypass valve. the dog bone forces oil down into the filter port from the oil pump. the afm relief doesn't really bypass the filter since it just vents to the pan, not into the engine passageways. the only really oil filter bypass valve is inside the filter itself. set at something like 12psi?

I don't remember, oil goes thru the filter before heading to the oil cooler right?

j91z28d1 said:

interesting. my 2011 yukon under shows the oil pressure relief valve for the afm stuff that screws inside the oil pan. shows the same type valve under the oil filter bypass valve and oil pressure relief valve. they look the same but different brands listed under each.

if I remember right there's not really a oil filter bypass valve. the dog bone forces oil down into the filter port from the oil pump. the afm relief doesn't really bypass the filter since it just vents to the pan, not into the engine passageways. the only really oil filter bypass valve is inside the filter itself. set at something like 12psi?

I don't remember, oil goes thru the filter before heading to the oil cooler right?

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IIRC, the oil starts in the pan, is pulled and pumped by the oil pump and then ran thru the filter, to parts unknown.

Just Fishing said:

On my tahoe, it's sensitive to oil level.
If i fill it to the F line on the dip stick, i get lower oil pressure.

I read it's something about the oil being foamed up by the crank.

If i keep the level just under the middle between full and add, it's much better overall.

But it might just be something with the replacement dipstick or the 2019 dated block i have.

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gooffeyguy said:

The MotorTrend show Engine Masters did an episode testing the amount of engine oil in the pan with an engine on the dyno. S3 E3 How Oil Kills Power.

Basically seeing the effects of more or less oil has on hp and oil pressure across the entire rpm range. A pan filled with the oil at the recommended level lost oil pressure at high rpms due to the airation and frothing of the oil by the crankshaft whipping it up. While the same test with 1 less quart of oil kept pressure and made more hp. Granted, this was above 5k rpms and most engines in daily driven vehicles won't be in that rpm range much to cause problems.

On that note, I've never added more then 6qts of oil when doing an oil/filter change, and I have the oil cooler.

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Yeah, definitely seems strange that I've had to add almost 7 qts to get it to full. I'm thinking of draining a qt out to see if that helps.

j91z28d1 said:

to the op. what radiator did you go with? maybe it's end tank is a bit restrictive? I don't know, just made me think when I was researching dwitts radiators they talked about the number of plates in there for more or less cooling. if you had a auto parts store one maybe it's just a tranny cooler on both ends with bigger fittings?

just thoughts.

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I went with the Denso 2219514. In looking at RA for my 2013 Tahoe, it for some reason lists it as the rad specifically for a PPV, but it's the correct one for use with an oil cooler. I've read multiple threads on here about it being a good OEM replacement, without breaking the bank.

The last few posts are about the oil path. Is 100% of the oil going through the cooler after the filter, or does some get diverted before the cooler?
If 100%, it's easy to see why I'd see some pressure drop after adding the cooler. It just seems like I'm seeing too much. I just had the front pumpkin out for my gear change project. I debated dropping the pan then to replace the o-ring, but right before the project I did some road testing that correlated RPM to pressure, and all seemed pretty good. Now I'm wondering if I should have.

I'm going to replace the sensor screen and maybe drain 1/2 to 1 qt out and see where I land after that.

gooffeyguy said:

That's called windage (not the same as in gun sights). They make pans with baffles or "windage trays" that bolt-on to help with this oil frothing. It can be a problem and cause loss of pressure at higher rpms

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The 07 6.2L L92 in my Denali came from the factory with a windage tray bolted to the mains and a baffles in the pan sump.
Some brands of oil have more anti-foaming additives than others.

DaveO9 said:

Yeah, definitely seems strange that I've had to add almost 7 qts to get it to full. I'm thinking of draining a qt out to see if that helps.



I went with the Denso 2219514. In looking at RA for my 2013 Tahoe, it for some reason lists it as the rad specifically for a PPV, but it's the correct one for use with an oil cooler. I've read multiple threads on here about it being a good OEM replacement, without breaking the bank.

The last few posts are about the oil path. Is 100% of the oil going through the cooler after the filter, or does some get diverted before the cooler?
If 100%, it's easy to see why I'd see some pressure drop after adding the cooler. It just seems like I'm seeing too much. I just had the front pumpkin out for my gear change project. I debated dropping the pan then to replace the o-ring, but right before the project I did some road testing that correlated RPM to pressure, and all seemed pretty good. Now I'm wondering if I should have.

I'm going to replace the sensor screen and maybe drain 1/2 to 1 qt out and see where I land after that.

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I believe it's all to the filter, with an internal bypass in the filter if needed and then up and to the oil cooler passageway, with the bypass in the aluminum block able to bypass that when flow right gets high enough and then up into the block.

so some sure. you do seem to be seeing more than I'd expect. and that seems to be a radiator everyone uses. so yeah I got nothing.

With the extended length that the oil has to travel, you would see a drop of a few pounds but 10 sounds like an awful lot.

Just for grins, I would swap in a new oil filter.
Never know, you could have a bad bypass valve.
Just a thought.

Wix makes filters, Delco buys them from a variety of sources. I trust Wix, Hastings, they both make filters. You know what you are paying for. I have had several GM trucks with and without the oil cooler lines, never noticed a pressure difference with and without the factory cooler.

DaveO9 said:

I just finished a build of many replacements and upgrades - documented here. One of the upgrades was the addition of an OEM-style engine oil cooler. I.e. I removed the block off plate, added a set of Dorman replacement lines, and replaced the radiator with a new Denso OEM-style that had the provisions for oil cooler. Great addition in my book, but now my oil pressure is lower. I went from just below 40 psi @2000 rpm, fully warm, to around 30 psi, same conditions. Is that expected? Other than an oil and filter change (same grade and brands as before: Costco synth 5w-30, AC Delco PF63) I didn't change or do anything else that should affect oil pressure.

Any concerns with oil pressure maxing out at around 30-33 psi. I think hot idle is around 15 psi. I have a new spare screen that goes below the oil press sender. I think I will try putting that in first to see if it helps.

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That's low and concerning to me given your setup. Put a new PF48 up there and drive it, then maybe change the lines out from Dorman to OE.

The best flowing, least restrictive, oil filters are the K&Ns with the 1" nut on the bottom. Nothing else comes close unless they (K&N) are lying.