what is considered a good oil pressure at 65mph and 40 mph in a i991 mx-5 150 000 on the clock

10

Asked by May 09, 2012 at 02:34 AM about the 1991 Mazda MX-5 Miata Base

Question type: Maintenance & Repair

car is dropping in oil pressure 10 pounds from 60 to 50 some times to 40 pounds and a little above 30 at a idle

2 Answers

12,675

As engines wear the tolerances between moving parts increases. How much this increases depends on several factors including frequency of oil changes.This can lead to lower oil pressures. With 150k you would have some normal wear. You will have a slight variation in pressures depending on engine rpm. If the lowest you go at idle is 30 you are fine. With an engine of 150k if you have over 30 all the time your engine is getting enough lubrication. You can run a high mileage oil to boost the pressure. Also if you notice quick variations in pressure you might want to manually check oil pressure. Its a possibility that your oil pressure transducer is becoming erratic.

1,135

If I read your question correctly, you are normally seeing 30psi @ idle, but as little as 10 between 50 and 60mph. Is that correct? If so, I might pull the sender and clean, or replace it. And as suggested above, put a manual gauge in the system to verify readings. If you are still see erratic readings you may have several problems. 1) Oil sludge in the pan which is clogging the oil pickup. 2) Build up (sludge) in the oil return galleys so oil is returning to the pan too slowly. 3) A weak bypass valve in the oil pump. 4) Bad oil pump or pump drive. 30psi @ idle is good, exceptional in fact. 10psi @ speed is not.

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

Search Mazda MX-5 Miata Questions

Mazda MX-5 Miata Experts

#1 Michael Kane
Michael Kane
Reputation 1,940
#2 Tom Demyan
Tom Demyan
Reputation 1,130
#3 Racer_X
Racer_X
Reputation 390
View All

Related Models For Sale

Used Ford Mustang
333 Great Deals out of 45,576 listings starting at $2,000
Used Chevrolet Corvette
117 Great Deals out of 20,536 listings starting at $3,499
Used BMW 3 Series
1,064 Great Deals out of 34,784 listings starting at $900
Used Chevrolet Camaro
136 Great Deals out of 35,100 listings starting at $1,995
Used Honda Civic
477 Great Deals out of 80,892 listings starting at $558

Used Cars For Sale

2017 Mazda MX-5 Miata For Sale
1,560 listings starting at $24,074
2016 Mazda MX-5 Miata For Sale
1,870 listings starting at $20,901
2015 Mazda MX-5 Miata For Sale
3 Great Deals out of 125 listings starting at $12,994
2014 Mazda MX-5 Miata For Sale
114 listings starting at $13,950
2013 Mazda MX-5 Miata For Sale
123 listings starting at $12,895