To check oil, what should engine temp be?

What is normal driving temp?

seeing if yall know offhand, sorry I'm too lazy to go grab the owner's manual.

 

For checking oil, warm up to 175 D F.

 

I get my coolant stable at 180 and oil temp stable at 170-174 (what mine runs at if I drive 20 miles or 200 miles).

 

I can drive for over 30 minutes at 75 mph in 5th and STILL not get the oil up to 175. I've even dropped down to 4th and not had the temp start to increase. But when I then roll into town and do Stop and Go at the lights, the temp will come up. It's been a real PITA so I have only checked the oil twice before the first servicing at 7200 miles. At that point I hadn't used a bit of oil.

 

I noticed mine got to 190* after normal driving, too hot? Brand new car

 

Coolant or oil temp?

 

Hummmm, not sure. i'll have to pay closer attention to what i was looking at next time

 

190* coolant temp is not an issue. 190* oil temp would be more concerning.

 

Why? The oil they use is good to over 300*F, few will get it that hot, but what's the problem with 190* oil temp?At 190* the oil level may be a little higher than at 175*, but nothing the owner would need to be concerned about.

 

It should be hot enough to flow like water--in practice anything over 150º is fine for checking the oil.

 

???.....It doesn't have to be 175 or any specific temp to check the oil. Just not cold. Just check it when you get home from a drive no matter the temp, it's at operating temp because you've been driving it.

 

The oil temp on my Wife's Jetta runs at 225 on the highway, it is turbocharged so that puts a lot of heat into the oil too though.

 

Sometimes I wonder why GM even prints an owner manual since so few people read them. From the 2020 OM:

 

175 Coolant temp, not oil temp.

 

I agree re the oil capability but there would have to be a reason for it being that high. On a hot day in the summer my coolant temp will not exceed ~185 F. Oil temp is typically 5 degrees less. I have both displayed. However when driving in Z Mode Powertrain set to Track and I accelerate on a 3/4 mile long road with farm fields on each side, stop at a stop sign then accelerate to merge into ~70 mile traffic on a 4 lane highway, then in about 100 yards brake aggressively to turn into the 25 mph limit rural road we live on and it will downshift and rev match 2 gears in the blink of an eye the oil temp will match the coolant temp which stays about same.

SIDEBAR
My 1st car was a 1967 Corvair which I modified with headers, carb mods, Plus 1 radials etc. When driven aggressively the oil temp (I added a gauge) would exceed 310F. Even with heavy weight oil I would use, would quickly break down and form a scrum on the oil intake tube. Chaged oil (and plugs) frequently. Then bought a 1974 Datsun 260Z the year new EPA emission rules made them add and exhaust air pump, run hot coolant in the intake manifold and a lean mixture. In 1974 the standard Corvette small block only had ~200 hp. Heck the 454 only 270 hp!

When hot and accelerating from a stop the Z would surge, slow and repeat. Datsun dealer had no idea what to do so asked to come then the Datsun Area Service Manger visited. Did and he said, don't quote me but put an oil Mobil is selling to the Military in Alaska called Mobil 1 in the dashpot of the two large Hitachi, Variable Venturi carbs. he said the oil was thinning out and causing the large piston to bounce up and down. It worked! Now in 1974 Moil 1 was a true synthetic Polyalphaolefin (PAO) base oil. Without many additives held it's viscosity even more that the 0 - 40 dyno oil Mobil and others sell today! It was expensive like 3 times the price of other oils and hard to get. Read that it was good for well over 300F and put it in my Corvair. Stopped the oil breakdown! (BTW around 2000 Mobil lost a lawsuit when they tried to stop Castrol from selling a more highly refined normal oil as "synthetic." A good Car & Driver article at the time said Mobil and a few others who were selling a PAO base oil had to change as it cost half to make the Castrol type! Yep Mobil 1 prices dropped in half!)

Although the oil can perform at higher temps it would indicate an issue with the engine oil cooler etc!

 

Not a problem, just don't believe "normal driving" should get the oil temp up to 190*. I haven't seen temps that high even driving in 110* Texas heat.

 

Oil temps running in the 200 degree range is perfectly normal.

 

The oil temp is controlled by a liquid to liquid heat exchanger. Oil temp will be close to coolant temp. The post I was replying to said temp doesn't matter, as long as the oil isn't cold. GM disagrees.

 

C7 / COS at Spring Mountain, late June air temp +105, I saw oil temps of ~280 after every track session, techs said “…..yep, for this time of year that is normal….”

 

Yep the liquid/liquid heat exchanger is not that big. So coolant can only keep oil so cool when Tracking. Note, smaller than my C7 Grand Sport oil cooler.