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

13,365

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.

1,205

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 of 1 people found this helpful.

Your Answer

Mazda MX-5 Miata Experts

  • #1
    Michael Kane
    Reputation
    2,090
  • #2
    Tom Demyan
    Reputation
    1,240
  • #3
    Racer_X
    Reputation
    390
View All

Related Models For Sale

Used Ford Mustang
590 Great Deals out of 39,474 listings starting at $1,895
Used Chevrolet Corvette
169 Great Deals out of 17,458 listings starting at $3,000
Used BMW 3 Series
1,112 Great Deals out of 32,916 listings starting at $1,200
Used Chevrolet Camaro
458 Great Deals out of 31,607 listings starting at $1,450
Used Honda Civic
798 Great Deals out of 60,931 listings starting at $950
Used Porsche 911
114 Great Deals out of 5,154 listings starting at $10,947

Used Cars For Sale

2017 Mazda MX-5 Miata For Sale
3 Great Deals out of 2,347 listings starting at $19,995
2016 Mazda MX-5 Miata For Sale
11 Great Deals out of 480 listings starting at $15,295
2015 Mazda MX-5 Miata For Sale
7 Great Deals out of 124 listings starting at $13,500
2014 Mazda MX-5 Miata For Sale
5 Great Deals out of 77 listings starting at $13,199
2013 Mazda MX-5 Miata For Sale
4 Great Deals out of 102 listings starting at $10,888

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.