This might be a dumb question...
Recently got a 95 miata and it is my first car with an active oil pressure gauge (that isnt a dummy gauge) (retrofit by PO)
Now, on a normal morning I start the car up and get a pretty instant response from the oil pressure gauge. (cold idle 50psi)
Now, on the recent frosty mornings I start it up and get NO reading for awhile until the car warms up. (we are talking several minutes)
Here are some deductions and assumptions.
Usual start the lifters tick in those instants before the pressure comes up, cold morning I have the same tick response (evidence that I have oil press, gauge is faulty)
Is it possible that the sensor is faulty in a thermally dependant way? I am not sure how this sensor operates, so could it just be "stuck" when its that cold?
Car runs and drives fine, great even. This is just something bothering me that I want to figure out. So is this normal, a sign of a faulty gauge, or motor problem (seriously doubting this).
Engine is a 96 1.8 that was put in to replace the OBD1 motor, motor switched to OBD1 if that matters.
Electric or mechanical gauge?
Pull the sender out and see if it has a gob of sludge plugging the hole.
its an electrical gauge, stock on the earlier miatas.
Other possibility if it's an electrical guage is to clean the contact at the sender. My Miata showed low oil press. and cleaning the contacts brought it up to normal.
In reply to Apexcarver:
You need thinner oil. My oil light (set for 40lbs) stays on even after the pressure climbs.
Look at your oil at those temps (in my case 20-50 at 32 degrees) - it will scare you!
my experience, good luck.
What oil filter are you using? Bet it don't have an anti-drain back valve. so over night all oil drains back to the pan..
44
Not positive of the filter or viscosity (have not yet done an oil change myself), but if I remember the PO correctly its 5w-30 and the filter is a K&N oil filter.
Cant see the filter, but can tell you its black and says made in the USA.
K&N oil filters were white last time i checked, it might be a napa one though, which is fine too.
so you all are getting low oil pressure on startup? that's a bit odd, on a cold morning I can just about get 90PSI oil pressure at idle and god only knows what once I start moving and applying throttle, then once the oil warms up it drops down to around 30PSI at idle and pushing to redline nets me about 60PSI, provided the 16 year old factory gauge can be trusted ('94 Miata, has an actual oil pressure gauge that tells me what pressure the oil is at, not the crappy one in later Miatas that either read "your engine good!" or "your engine asplode")
