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Hi folks,

Recently picked up a couple of gauges (or rather one multigauge but who's counting) and curious what sort of numbers I'd expect to see in a standard NB. Oil pressure, oil temp, coolant temp.

Specifically I'm interested in figuring out where to set the min/max alarms for each sensor, and I'm sure I could figure it out myself through observations, but figured it wouldn't hurt to canvas the room as well.

ball park ranges


Engine temp: 80-100*C depending on ambient, traffic, thermostat, AC on of off, radiator...

Oil temp: 90 - 120*C In standard form, ~ 10*c higher than water temp unless you're on it. Ideally on longer drives you want it over 100*C. Good synthetic modern oils are good upto 130*C, but if it's getting that high just driving around, you've got the calibration wrong, or something else is a miss.

Oil pressure: depends of revs, oil & engine temp but around 200kPa at idle, upto about 300kPa at 7000 at about 90*C watertemp. You'll see more with a thicker oil, at start up etc.

my car hasn't been standard for a while, or dríven on the road much, so the numbers (especially OP) might be on the piss.

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Oil temp is sensitive to revs, you will see it go up when you are revving hard. I am a fan of water/oil heat exchangers, the coolant brings the oil up to temp quickly, it is interesting to sit in the car and watch them climb together with oil lagging coolant. In a high revving car, ¬80*c is where you can give it plenty of stick - more critical with big cams. Getting to 80* on a cold Goulburn morning can be harder than you think, the heat exchanger fixed that. The caveat is that your radiator needs the capacity to shed both coolant and oil heat. Measuring OT, location is not critical IMHO, but the yanks like the sensor in the sump plug if another location in the sump can't be used. I am measuring both OT and OP immediately before the cooler.

I have a pair of Longacre sensors for coolant - temperature and pressure, yet to be installed. The CT is the traditional sensor, the CP is meant to tell you have a leak in your coolant, independent of temperature, and is set for something like 4 or 5psi - both are wired to warning lights (I am going to see if I can join them and use a single light). I have twice lost an engine when there was no water to trigger the temperature gauge, I'd rather not make it a hat trick.