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Discussion Starter · #1 ·
hey guys i recently hit 4500 miles and did my oil change a little over the 3k mark. however lately its been getting in the 20-30 degree f. i notice when i go and start my st up that the oil pressure is normal at 35psi however once i get on the gas it shoots up very high nearing the 70psi mark. should i be nervous? i let the car warm up for 3-4 minutes before i hit the road. i guess i never really looked at the oil pressure gauge but don't want to cause any damage so i figured id ask where people actually know these cars. Thanks!
 

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Mine does it too, I think its normal during a cold start, since the oil is cold too. I dont rev the engine, until it gets all to normal and warm.
 

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That's normal. When it's cold oil has a high viscosity and because of this the pressure starts high and then works its way down when oil is up to temp


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Discussion Starter · #4 ·
ok cool thats what i figured, it just seemed high to me so i wanted to make sure that its actually normal,but thanks for the quick responses guys!
 

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I don't know if you know this, but the Focus ST and Fiesta ST do not have a oil pressure or oil temperature sensor. It is all inferred within the PCM based on inputs such as RPM's, coolant temperature, ambient air temperatures, vehicle speed, throttle inputs, etc.

The PCM actually has no clue what the oil pressure or temperature is, it just guesses.

There is a oil pressure switch that is hard wired to the PCM. Basically when the oil pressure is low enough, the switch will close and allow voltage to travel from the PCM to the PCM. This voltage signal tells the PCM it needs to network a message to the IC (instrument cluster) to turn on the dummy light. Even when this occurs, the PCM still does not know what the pressure is, just that it is low.
 
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Discussion Starter · #6 ·
very good to know thanks
 
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Wait how does the two gauges work then?

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The computer is essentially guessing what the value should be. That being said, Ford has done extensive research on the formulas used when calculating these values and I think it is safe to say that they are very close to actuals.
 
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hey guys i recently hit 4500 miles and did my oil change a little over the 3k mark. however lately its been getting in the 20-30 degree f. i notice when i go and start my st up that the oil pressure is normal at 35psi however once i get on the gas it shoots up very high nearing the 70psi mark. should i be nervous? i let the car warm up for 3-4 minutes before i hit the road. i guess i never really looked at the oil pressure gauge but don't want to cause any damage so i figured id ask where people actually know these cars. Thanks!
There's no need to do this. The engine will warm up better if you just drive it. Just don't run the p*ss out of it.
 

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There's no need to do this. The engine will warm up better if you just drive it. Just don't run the p*ss out of it.
With a turbo it is good to let it warm up a little (30-60 seconds in warm weather) before heading off and letting it cool for about a minute before shutting off.
 

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With a turbo it is good to let it warm up a little (30-60 seconds in warm weather) before heading off and letting it cool for about a minute before shutting off.
Sit in the car after normal driving for a minute? That's old school. We have water cooled turbos, and the coolant continues following with the motor off making extra idling unnecessary. After hard driving, sure. Normal driving, not so much.
 

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Sit in the car after normal driving for a minute? That's old school. We have water cooled turbos, and the coolant continues following with the motor off making extra idling unnecessary. After hard driving, sure. Normal driving, not so much.
I'll stick to my ways. A minute isn't much wasted.
 
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Think they are talking with wind chill it is around -32C here now.... Looks like I just pretty much won't be using turbo for a few months haha.
 

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Think they are talking with wind chill it is around -32C here now.... Looks like I just pretty much won't be using turbo for a few months haha.
It's not quite as cold in Buffalo yet, but I'm considering throwing on my 5psi max map. I have about a 7 mile drive to work. Taking it real easy the other day I almost made it all the way by never hitting boost, but then I got just a slight bit heavy for a moment. I was sitting at max of -0.01psi for a while.
 

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