Oil Temperature in Cooler Weather
 

So it is starting to get chilly around here in Houston, and today as I was driving to work (~50 degrees outside @ 7:30AM) I noticed that my oil temperature sensor was only reading around 160°F... This was highway driving at 70mph for about 30 minutes. At the end of my drive temperatures rose as my average speed dropped, but did not even approach 180°F.

I have the Stillen 25 row oil cooler, which worked great during the summer. However it was my impression that the thermostatic plate only allows flow through the exchanger @ 180° or higher... Am I going to run into any problems daily driving it through the winter? Why does the temp not go up to 180 and just stay there?

The thermostatic plate still allows for some flow to the oil cooler (usually around 10%) even when it's "closed."

You'll need to fab up a sheet-metal cover to partially cover the oil cooler during the cooler months to ensure the oil warms up to ideal operating temperatures.

The oil cooler is just doing its job, but the thermostatic plate still allows oil to flow through otherwise if it opened all at once when it hit 180 degrees, you would get a shock of cold oil to the system which is not good. What temperatures have you been seeing? I have the same cooler as you and I see 160-170 degrees when cruising at 70 on a cooler day/night but that is about as low as it goes.

160 is what I have been seeing the past few days; obviously if I gun it or get into start stop traffic it gets up to a reasonable 180 - 190. I am just concerned about viscosity levels at these lower temperatures.

For normal operation you want to be at 180+

Hmm ok, I guess I'll need to look into this cover thing.

I'm rethinking the cover depending on how things go. Temp this morning was 35F and I still got to 160-170 by the time I got to work (10mi on highway). If you don't drive on the highway, a cover is probably completely unnecessary. Coming home in 45F temps, I got to my 200F thermostat temp pretty quickly.

A good synthetic oil really shouldn't have any problem lubricating the engine at 160F.

kkruel, just put a TT kit on the car and you will be fine. :p

slap a few pieces of blue painters tape on the oil cooler, ghetto but effective

Hell, use duct tape if you don't care about residue. I may just do this...

+rep

There are plenty of cars with oil coolers from the factory. So what happens to them in cold weather? Do they have better thermostats or do the manufacturers just assume they'll run cold in the winter (lesser of two evils as opposed to running too hot in summer)?

Nope, they do one better. They don't have a gauge so people like us don't complain and worry about it.

I chose blue painters tape because it doesn't leave residue. Once it is installed, it's hard to slide anything over the oil cooler. Soft blue tape seems to work best.

How many times do you have to retape during a cold season?

Hve a 200* F thermostat fitted to it -- problem solved.

I have a 200F thermostat. There is still some oil flow through the cooler even below 200F, so the engine takes a bit longer to warm up. When it's 0F, it's going to take a really long time to warm up.