lm7 5.3 oil temp?
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Teching In
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lm7 5.3 oil temp? I have a 01 silverado with a rebuild lm7 5.3(oversized pistons, rods, cam, etcc). I do have Efans installed and the truck flashed and they work fine. I have an AEM oil temp gauge and I noticed when cruising(70-80mph @2k rpm) on the highway it'll reach 230 degrees(220 in the city). Coolant temps always stay fine(190-205degrees) Should I be worried? Should I think about an oil cooler?? Anything helps thanks.
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I have a 01 silverado with a rebuild lm7 5.3(oversized pistons, rods, cam, etcc). I do have Efans installed and the truck flashed and they work fine. I have an AEM oil temp gauge and I noticed when cruising(70-80mph @2k rpm) on the highway it'll reach 230 degrees(220 in the city). Coolant temps always stay fine(190-205degrees) Should I be worried? Should I think about an oil cooler?? Anything helps thanks.
Did you just install the guage? I've never monitored oil temperatures, just use the stock gauges.
I've got an L59 swapped in my 99 Silverado w/o the external engine oil cooler and a 06 Suburban 2500 LQ4 that has the engine oil cooler. Both seem to run at the same temperature in the summer when it gets really hot. Both have mechanical fans though.
Seems like the engine oil cooler was more like for heavier towing. If you do a lot of towing in the upper range of the rated capacity, probably a good idea to add one.
Oil is heated primarily by RPM's. At 2K, it's not under a lot of stress. It should be about 10'ish* warmer than water temps. Your oil temps shouldn't be any higher than about 215* or so.
Around town, the oil should get a little bit warmer; variable RPM's, more load, less air flow.
I'd say something may be wrong with your gauge. Where is the probe/sender located?
Around town, the oil should get a little bit warmer; variable RPM's, more load, less air flow.
I'd say something may be wrong with your gauge. Where is the probe/sender located?
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I have a 01 silverado with a rebuild lm7 5.3(oversized pistons, rods, cam, etcc). I do have Efans installed and the truck flashed and they work fine. I have an AEM oil temp gauge and I noticed when cruising(70-80mph @2k rpm) on the highway it'll reach 230 degrees(220 in the city). Coolant temps always stay fine(190-205degrees) Should I be worried? Should I think about an oil cooler?? Anything helps thanks.
Oil temp under 220°F is too cool. It won't boil off any condensation or water vapor from blow by at those low temps.
Back in my road racing days, I wanted those same temps for long endurance races (6 hours or longer). For shorter endurance races, I'd want engine coolant temp below 235°F and oil temp below 260°F. For short sprint races (100 miles or less), I would let it run to maybe 245°F to 250°F on the coolant temp and up to about 275°F on the oil temp. I'd block the radiator to get the temperatures in range because generally there was less drag and more top speed with less air going under the car through the radiator. Oh, and I did run 20PSI caps on all my race cars. So there was some added protection from boiling the coolant with that extra pressure.
Water will evaporate at ambient pressure and temperature. It does not need to be above 212* or 220*. If that were not true, your kitchen floor would never be dry.
Engine oil temps generally run close to coolant temps. With the factory thermostat opening at 190*, coolant temps for most cars stays around 190*, with oil temps around 200-210*. All winter long. And yet, UOA's rarely show any water.
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Water that's exposed to air will evaporate. Water in your oil is nearly never exposed to air. If the water in your oil boils, it becomes steam, expands and bubbles out of the oil, and it's expanding with enough force to break the surface of the bubbles and totally escape into the air in the crank case.
Try this experiment. Take two small glass jars. Use some you're throwing away or recycling, even old beer bottles will work for this, although open mouth jars would be better. Put 2 or 3 tablespoons of water in the bottom of each jar. Add a few ounces of motor oil to one jar. Set those jars in a sunny, dry place. Check them every day to see how the evaporation thing is working for you. If you want, you can even put the lids on and shake both jars a few times a day. Shake the one with the oil in it until you get a milky emulsion if you want.
I'll bet a $10 donation to St. Judes that the water by itself will evaporate in a few days, and the water in the jar with the motor oil won't evaporate at anywhere near the same rate.
Care to accept the bet. I'll let you post the pix of progress somewhere here.
And most cars today run a 195°F thermostat and see oil temps of 215°F to 220°F. Some run even hotter thermostats than that (95°C/203°F is pretty common on imports and even some newer GM engines), with engine coolant "operating" temps over 215°F, with engine oil temps in the 230°F to 240°F range.
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Yes it’s fine. My engine oil runs about 20-30 hotter then the coolant temp. If I’m normal driving. It goes up 30-40 hotter if I drive at wot. But goes right back down. Moisture will start to come out of the oil once the temperature goes above dew point.(no longer condensing) Depending on what pressures inside the crankcase a positive crankcase pressure will decrease moisture removal. A negative pressure will increase moisture removal. Hot oil will
release moisture quicker then a cooler oil, but that’s dependent on the pressure.
release moisture quicker then a cooler oil, but that’s dependent on the pressure.
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Water that's exposed to air will evaporate. Water in your oil is nearly never exposed to air. If the water in your oil boils, it becomes steam, expands and bubbles out of the oil, and it's expanding with enough force to break the surface of the bubbles and totally escape into the air in the crank case.
Try this experiment. Take two small glass jars. Use some you're throwing away or recycling, even old beer bottles will work for this, although open mouth jars would be better. Put 2 or 3 tablespoons of water in the bottom of each jar. Add a few ounces of motor oil to one jar. Set those jars in a sunny, dry place. Check them every day to see how the evaporation thing is working for you. If you want, you can even put the lids on and shake both jars a few times a day. Shake the one with the oil in it until you get a milky emulsion if you want.
Water that's exposed to air will evaporate. Water in your oil is nearly never exposed to air. If the water in your oil boils, it becomes steam, expands and bubbles out of the oil, and it's expanding with enough force to break the surface of the bubbles and totally escape into the air in the crank case.
Try this experiment. Take two small glass jars. Use some you're throwing away or recycling, even old beer bottles will work for this, although open mouth jars would be better. Put 2 or 3 tablespoons of water in the bottom of each jar. Add a few ounces of motor oil to one jar. Set those jars in a sunny, dry place. Check them every day to see how the evaporation thing is working for you. If you want, you can even put the lids on and shake both jars a few times a day. Shake the one with the oil in it until you get a milky emulsion if you want.
My diesel engine runs about 175* most of the time. Yes, the engine is all stock, including the thermostat. Oil temps are not much higher, since it generally runs at rpm's <2,000. When I do a UOA, the water content is 0. Keep in mind that this a stock 2020 engine, with all stock emissions equipment in place and functioning. I think the only time I'v ever seen engine temps above 200* was pulling a long hill in Utah at 80mph.
Hypothesis proven with actual real world data.
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And just because the gauge says your oil is at 180…or whatever…doesn’t mean that all the oil is that temp. Oil slinging up into the cylinders from the rod bearings is hitting the super hot pistons and cylinder walls, causing that small, tiny amount of oil to get very very hot, and instantly boiling out any condensation in the oil, a tiny little bit at a time…(while at the same time cooling the pistons and cylinder walls…there is a constant exchange of thermal properties goin on inside an internal combustion engine by design, by both coolant and oil)
But at rpm and with run time, that tiny amount of oil is doing this hundreds of thousands of times…easily boiling out any and all condensation. The super-heated oil spray mixes back into the main bulk of the oil sump and cools back down quickly. Oil coolers are everyones friend, especially with engine mods which add heat.
But at rpm and with run time, that tiny amount of oil is doing this hundreds of thousands of times…easily boiling out any and all condensation. The super-heated oil spray mixes back into the main bulk of the oil sump and cools back down quickly. Oil coolers are everyones friend, especially with engine mods which add heat.
OK, now you're reaching. It's a good theory, and I can see it's merits. But you have no data to back it up.
You're saying that the oil in the engine is actually 40-50* hotter than what's in the sump, which is where most people measure the temps. When I see 180* on the gauge, it's really 220-230* in the engine. If you are correct, then you would want to see sump temps <200* or so.
As it pertains to this particular discussion, the OP see's an oil temp of 230*. That means the temp in the engine is 270-280*. In long term street use, that's not good. Those temps lead to increased component wear and decreased oil life.
You're saying that the oil in the engine is actually 40-50* hotter than what's in the sump, which is where most people measure the temps. When I see 180* on the gauge, it's really 220-230* in the engine. If you are correct, then you would want to see sump temps <200* or so.
As it pertains to this particular discussion, the OP see's an oil temp of 230*. That means the temp in the engine is 270-280*. In long term street use, that's not good. Those temps lead to increased component wear and decreased oil life.
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You're saying that the oil in the engine is actually 40-50* hotter than what's in the sump, which is where most people measure the temps. When I see 180* on the gauge, it's really 220-230* in the engine. If you are correct, then you would want to see sump temps <200* or so.
I try to place my oil temp sender as close to the bearings as I can. I want to know the temperature of the oil when it gets to the bearings. That's the most important temperature. So usually I'll put it in where one of the oil galley plugs is, or in the filter bracket, in the path of the filtered oil going to the engine. Every factory installed oil temperature sensor I've seen has been located in a similar location, after the filter (and after the oil cooler if equipped), before the bearings.
And most of the cars I've owned (or currently own) that have "oil coolers" that are coolant-oil heat exchangers. My older VW/Audi engines have a cooler of that type at the filter bracket, cooling the oil from the pump to the oil filter. My Chevrolet trucks have a plate cooler in the hot side tank of the radiator (the tank with the upper radiator hose connected to it. So my engine oil temp at it's coolest point is still going to be hotter than the engine coolant.
Oil in the sump will be hotter than my gauges show. How much hotter depends on the engine. A turbocharged engine with oil cooled pistons (squirters under the pistons that squirt oil to the bottom of the piston surface) will have much hotter oil in the sump, and that engine oil temp will spike under boost conditions. I have those piston cooling jets in some of my NA engines as well, and again, the oil in the sump will pick up heat from the pistons on those engines, especially at high RPMs and high loads (WOT). That's why on some of those engines, I've installed finned aluminum oil pans to cool the oil in the sump.
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My oil doesn’t go over 220* (after pump in the port that’s on side of the block is where my temperature is taken) oil is getting way hotter then that as described earlier. Reason I don’t want my to go over 220 is be because of my bearing clearances are set for 5w30. If I had oil temps over 220 I’d install a larger plate cooler.
230 oil temps the coolant will be lower by 20-30 degrees. The coolant is the coolest liquid inside the engine. The oil is helping transfer the heat into the coolant. Think piston squirters the hot piston gives its heat up to the cooler oil, the oil will give its heat up to the cooler block that has coolant cycling through it. The radiator is giving up its heat to the ambient air outside.
Last edited by jasons69chevelle; Jun 1, 2023 at 01:02 PM.
I don't know about "most people." I've never seen any factory installed oil temperature sensor in the sump. And I've never installed one there.
I try to place my oil temp sender as close to the bearings as I can. I want to know the temperature of the oil when it gets to the bearings. That's the most important temperature. So usually I'll put it in where one of the oil galley plugs is, or in the filter bracket, in the path of the filtered oil going to the engine. Every factory installed oil temperature sensor I've seen has been located in a similar location, after the filter (and after the oil cooler if equipped), before the bearings.
And most of the cars I've owned (or currently own) that have "oil coolers" that are coolant-oil heat exchangers. My older VW/Audi engines have a cooler of that type at the filter bracket, cooling the oil from the pump to the oil filter. My Chevrolet trucks have a plate cooler in the hot side tank of the radiator (the tank with the upper radiator hose connected to it. So my engine oil temp at it's coolest point is still going to be hotter than the engine coolant.
Oil in the sump will be hotter than my gauges show. How much hotter depends on the engine. A turbocharged engine with oil cooled pistons (squirters under the pistons that squirt oil to the bottom of the piston surface) will have much hotter oil in the sump, and that engine oil temp will spike under boost conditions. I have those piston cooling jets in some of my NA engines as well, and again, the oil in the sump will pick up heat from the pistons on those engines, especially at high RPMs and high loads (WOT). That's why on some of those engines, I've installed finned aluminum oil pans to cool the oil in the sump.
I try to place my oil temp sender as close to the bearings as I can. I want to know the temperature of the oil when it gets to the bearings. That's the most important temperature. So usually I'll put it in where one of the oil galley plugs is, or in the filter bracket, in the path of the filtered oil going to the engine. Every factory installed oil temperature sensor I've seen has been located in a similar location, after the filter (and after the oil cooler if equipped), before the bearings.
And most of the cars I've owned (or currently own) that have "oil coolers" that are coolant-oil heat exchangers. My older VW/Audi engines have a cooler of that type at the filter bracket, cooling the oil from the pump to the oil filter. My Chevrolet trucks have a plate cooler in the hot side tank of the radiator (the tank with the upper radiator hose connected to it. So my engine oil temp at it's coolest point is still going to be hotter than the engine coolant.
Oil in the sump will be hotter than my gauges show. How much hotter depends on the engine. A turbocharged engine with oil cooled pistons (squirters under the pistons that squirt oil to the bottom of the piston surface) will have much hotter oil in the sump, and that engine oil temp will spike under boost conditions. I have those piston cooling jets in some of my NA engines as well, and again, the oil in the sump will pick up heat from the pistons on those engines, especially at high RPMs and high loads (WOT). That's why on some of those engines, I've installed finned aluminum oil pans to cool the oil in the sump.
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I use the factory style oil cooler lines that go into a radiator with the factory style cooler in the driverside. Oil comes up to temp more quickly and does not get as hot at prolonged heavy load. Without an oil cooler at all my L31 350 would run 50-75F higher oil temps than coolant temps. A LS engine that is really working hard is similar. A heavily loaded engine even at relatively low rpm will heat the oil to a point it is well over the safe operating temperature of the oil. I also agree that the coolest oil in the engine is the oil in the sump. Engines that run hard on dinosaur oils without a cooler tend to coke up the underside of the pistons with a thick layer of crunchy buildup. Synthetic oil and the factory oil cooler keep the pistons free of that buildup.
On the irrigation engines I have worked on, we throw a 20' loop of copper tubing into the discharge water that is coming out of the ground at 50-60F. Those engines run at about 80% load at 2,000 rpm day and night. Without the oil cooler tubing loop oil temps will run away in that kind of use. The most effective fluid cooling is fluid to fluid not fluid to air.
On the irrigation engines I have worked on, we throw a 20' loop of copper tubing into the discharge water that is coming out of the ground at 50-60F. Those engines run at about 80% load at 2,000 rpm day and night. Without the oil cooler tubing loop oil temps will run away in that kind of use. The most effective fluid cooling is fluid to fluid not fluid to air.
Last edited by Fast355; Jun 4, 2023 at 09:04 AM.
OK, now you're reaching. It's a good theory, and I can see it's merits. But you have no data to back it up.
You're saying that the oil in the engine is actually 40-50* hotter than what's in the sump, which is where most people measure the temps. When I see 180* on the gauge, it's really 220-230* in the engine. If you are correct, then you would want to see sump temps <200* or so.
As it pertains to this particular discussion, the OP see's an oil temp of 230*. That means the temp in the engine is 270-280*. In long term street use, that's not good. Those temps lead to increased component wear and decreased oil life.
You're saying that the oil in the engine is actually 40-50* hotter than what's in the sump, which is where most people measure the temps. When I see 180* on the gauge, it's really 220-230* in the engine. If you are correct, then you would want to see sump temps <200* or so.
As it pertains to this particular discussion, the OP see's an oil temp of 230*. That means the temp in the engine is 270-280*. In long term street use, that's not good. Those temps lead to increased component wear and decreased oil life.
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Teching In
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*update* I have a 01 silverado with a rebuild lm7 5.3(oversized pistons, rods, cam, etcc). I do have Efans installed and the truck flashed and they work fine. I have an AEM oil temp gauge and I noticed when cruising(70-80mph @2k rpm) on the highway it'll reach 230 degrees(220 in the city). Coolant temps always stay fine(190-205degrees) Should I be worried? Should I think about an oil cooler?? Anything helps thanks.
*UPDATE*
I just installed an oil cooler last night and did 20miles of driving(highway/city). On the highway oil temp stayed around 201 degrees cruising at 80mph(temp outside was 60-65 at night). Also for those who asked I have an AEM temp sensor in the oil pan side plate, which I have a special adapter that allows me to run AN lines to my cooler now. I’m curious to see temps on a hotter day, I will update for those who are also curious. Thank you for everyone’s input!