My '92 Miata with about 90K, has been pegging the oil pressure gauge at the
Is this possible?? Any way to find out without the big $$? All input is welcome. Thoughts. Thanks!
Sounds plausible to me. Mine's a 94, but the shop manual for it says the oil relief valve is designed to kick in between 50 and 63 psi.
The danger with your high pressure is that it could blow out the filter element in your oil filter and send it and all the crud thru your engine.
Hope I'm wrong, but it does sound like big bucks. Might be cheaper to buy a used engine in known good condition than to spend the labor to rebuild the one you have. Engine usually has to come out to change the pump - unless your mechanic is really good.
Thanks for the suggestion. I have the car at another shop today for a 2nd opinion. I watched the gauge very closely as we drove this weekend, and it does start out getting at or near 90 psi with the engine cold, but within
2-3 minutes as the motor warms up, the pressure begins to hang out at or below 60 psi, and I can see the relief valve working as I run up the RPM's. Appears the pressure climbs until about 62-65 psi, as RPM increase, then at about 2500-2700rpm, the pressure drops back to slightly under 60 and pretty much holds there as we drove. At idle, I have about 30 psi, again, all on the car gauge. I'll update this message tonight. Thanks to all who posted.
You've just described the normal operation of a healthy Miata engine with a real oil pressure gauge. Stop worrying.
I'd agree, since the idle oil pressure is more or less normal. The 90 psi (if actual) is a bit high though, unless heavy oil is used. Given the factory oil pressure gauges, I'd want to check with an accurate gauge before deciding to do anything.
It's perfectly normal for 10W-30 in subfreezing weather.
Yes, 90 cold is, even at idle if sufficiently cold.
But the cited numbers when the oil is fully warmed up, like 30 at idle, seem too high. I could imagine that the mechanic who wanted to change the $$$ oil pump, and who was apparently unaware that the oil pressure depends on oil temperature, put in the wrong weight of oil. If the oil pressure after say 30 minutes driving is not well below the 30 mark, say 20, I would take the safe route and replace the oil.
Leon
I took it to another respected shop today and they said all was well, and they did not recommend doing anything but driving it and having a good time. They said you must check the pressure after engine warmup, and mine had very normal pressure at that time, and at all RPM's. Thanks everyone for all the input. Happy holidays!
Great Christmas present! Now, you need to make sure you never, ever, go back to the shop that wanted to replace your oil pump unless it is to tell them they are buffons.
Tom
92 RedSolara wrote:
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