Why does this only happen in the cold...

"SaigaShooter - He's got an Impreza" (saigashooter)
02/25/2019 at 17:11 • Filed to: None

No not the snow, I know that happens in the cold. What has me miffed today is that all winter I only get a low oil light when the temperature has been below 0.

Not a big problem, but for some reason, this car’s hood hates to latch when it’s that cold. Now I ge t to drive around until the hood magically decides to latch completely, or I get sick of watching it bounce and actually take the time to see what the hell is wro ng with i t .

My neighbors really need to turn off the Christmas lights

DISCUSSION (13)

farscythe - makin da cawfee! > SaigaShooter - He's got an Impreza
02/25/2019 at 17:29

duct tape will fix the bouncing

vicali > SaigaShooter - He's got an Impreza
02/25/2019 at 17:33

I put 10-40W in the Jetta once and tried to drive it through the winter.. It was not happy. It was m uch nicer when I used the right oil.

SaigaShooter - He's got an Impreza > farscythe - makin da cawfee!
02/25/2019 at 17:45

Perhaps chrome hood pins, class it up a little! /s

farscythe - makin da cawfee! > SaigaShooter - He's got an Impreza
02/25/2019 at 17:46

im not a classy guy :)

you do you lol

Khalbali > SaigaShooter - He's got an Impreza
02/25/2019 at 17:46

Maybe the oil is just too thick to flow so it reads low pressure?

TahoeSTi > SaigaShooter - He's got an Impreza
02/25/2019 at 17:47

oil pick up tube could be cracked....I’ve had to deal with that once before.

benjrblant > SaigaShooter - He's got an Impreza
02/25/2019 at 18:28

Are you using the recommended viscosity for winter temperatures ? Cold oil may be too thick to flow well and could provide insufficient oil pressure. I’d expect this to go away as the engine warms up and the oil reaches operating temp.

Just a guess.

jimz > Khalbali
02/25/2019 at 19:24

nah, oil is incompressible, the pump will push it (so long as the pump doesn’t lose its prime.) it’ll just use more engine power to do so. What’s more likely is the cold oil isn’t draining back into the sump fast enough, and the pump is getting gulps of air.

or, the oil pressure switch could just be sticky when cold.

Fuckkinja > SaigaShooter - He's got an Impreza
02/25/2019 at 20:29

Grease the catch and cable. Let it warm up till the thermostat opens. Clean roof off. Typical winter requirements.

Don’t break the cable unless ur hood has released. Been there. New hood.

gogmorgo - rowing gears in a Grand Cherokee > SaigaShooter - He's got an Impreza
02/25/2019 at 20:40

Some greases don’t much care for the cold, and get gummy, and stop things from moving, especially if the grease is dirty. Moisture in a latch cable freezing and/or the sheath getting stiff could also cause problems. For the latch some penetrating oil to clean it up, and then either fresh grease (I like the white lithium spray myself) or an oil-based lubricant. For the cable, you might get lucky with penetrating oil, but bicycle cable lubes are excellent for hood cables .

tromoly > jimz
02/25/2019 at 20:51

No he’s right, if oil is too thick it’ll cause the pump to cavitate and oil pressure to drop, that is why letting the oil warm up properly before putting load and spinning the oil pump harder is necessary to prevent damage.

jimz > tromoly
02/25/2019 at 21:10

uh, no. cavitation is a physical phenomenon where the fluid being pumped drops below its vapor pressure and forms destructive bubbles in the low pressure regions.

https://en.wikipedia.org/wiki/Cavitation

cold motor oil is not going to cavitate. next time try to know what you’re talking about.

tromoly > jimz
02/25/2019 at 21:20

Point #7 at this link: https://www.machinerylubrication.com/Read/28767/gear-pump-cavitation

Fifth item in the chart at this link: https://books.google.com/books?id=K2CkjoYZDDUC&pg=PA798&lpg=PA798&dq=too+thick+oil+causing+cavitation&source=bl&ots=94UUkN4Eis&sig=ACfU3U3fP3K_YwZiU5ly-FyXZNSe0oB1fQ&hl=en&sa=X&ved=2ahUKEwi2jZbOqtjgAhVF54MKHdoeCjgQ6AEwD3oECAQQAQ#v=onepage&q=too%20thick%20oil%20causing%20cavitation&f=false