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Discussion Starter #1
To all,

This morning I had -10F on the dash, although I know it was much colder than that because the sensor in my house was -18F. Anyways, the last few days my coolant has had a brown sheen to it, the dealer put some conditioner in the car which looked like rusted metal. I thought I had blown a head gasket but I can't find any traces of water and the car is not burning coolant. This morning I had unusual oil pressure all though within means of the factory oil pressure. I had a reading just about 60 but not past 70. Normally the car operates around 75psi or higher. I'm thinking with cold weather this would make the oil pressure so thick that I would have really high oil viscosity + pressue. I could be wrong though. My DEFI sensor is getting old, I bought it when I bought the car with zero miles on it, could also be that. Car has 105K on it and has been running fine. My question is, does cold weather have this impact? Even when the engine is at normal temp?
 

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If your oil warm-up starts at ambient...it will take longer for the temp to rise to normal operating temperature if you start at -18 vs 70 degrees.

Cold temps do odd things to cars/mechanics too. The gauge maybe experiencing this. I've always understood coolant will hit normal temps much quicker than oil...oil is primarily warmed by friction (engine rotations) where as coolant is combustion events heat.

I would expect oil pressure to be higher and remain higher until things stabilize...again maybe a gauge issue.

I'm very cautious with an engine at those temps...serious thermal shock/thick oil-I increase my warmup process.
 

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Engine oil was running at 60PSI, I decided to change it even though I just changed it about 1000 miles ago. Back up to normal pressure, wondering if the oil was bad? When I changed it, it came out like water and had a green tint to it. Looking at the new oil, that has a green tint to it as well but the viscosity is thicker (5w-30). Strange.
 

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Engine oil was running at 60PSI, I decided to change it even though I just changed it about 1000 miles ago. Back up to normal pressure, wondering if the oil was bad? When I changed it, it came out like water and had a green tint to it. Looking at the new oil, that has a green tint to it as well but the viscosity is thicker (5w-30). Strange.
green? what oil is green? (most engine oil is a yellowish-amber color) if it wasn't green when you put it in, you have a problem...

hot oil, will pour out of the sump very easily. If your oil was NOT hot and still came out "like water" then something is not right...

FWIW, any time I am on the throttle, my oil pressure guage reads close to 85-90psi. Full temp idling is usually around 30psi. I use 10-w40 Amsoil.
 

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I would expect oil pressure to be higher and remain higher until things stabilize...again maybe a gauge issue.
my oil pressure on cold startups is closer to 100psi (even at cold idle). I usually warm up 5 minutes or so before driving on really cold mornings; but "really cold" for me is anything below 40°...
 

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Think the oil pressure reading will be different depending on where the pressure sensor is fitted. I have my oil pressure readings taken from the sandwich plate between the oil filter and block. On a cold start my oil pressure is about 100psi and while driving at normal operating temps im 80-95 depending on throttle input. At idle once the car is warmed up my oil pressure is 38-40psi

Cold weather can cause the mechanical gauge to freeze up a bit at times. Its happened to me and if it does happen it usually fixes it self with in a minute or so. What kind of oil are you using? Are you saying that you see oil mixed in your coolant inside the coolant tank? If you took it to the dealer and it wasnt like that before, call them and inform them of whats going on. Lets not jump to conclusions just yet.
 

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Discussion Starter #7
I want to follow up on this, the Bosch oil filter I've been using have been killing my oil pressure. I switch to a different oil filter and my oil pressure went back up to there it use to be.
 
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