Reading Engine Oil Level
Thread Starter
Advanced
Joined: Apr 2018
Posts: 83
Likes: 8
From: TX
Reading Engine Oil Level
I know this is a noob question.
I just finished changing the oil in my 89 Carrera. Previously the oil guage when the car is fully warmed up, idling, and on a level surface, would already read at about halfway between the half mark and the boom red line.
After changing the oil, the oil level on my dipstick when fully warmed up, idling, and on a level surface, is at about the half way mark, BUT, when idling, the oil guage reads all the way to the TOP of the guage... When I'm on the gas however, the guage reads right at the half way mark.
I filled it up with 9 quarts initially and after a drive was about 25% up from the low mark, so I put another quart in it. In fear of over filling the oil, I drained about .3 quarts.
Is this behavior normal? Should I be concerned if my oil guage is reading that high, but my dipstick is reading normally?
I just finished changing the oil in my 89 Carrera. Previously the oil guage when the car is fully warmed up, idling, and on a level surface, would already read at about halfway between the half mark and the boom red line.
After changing the oil, the oil level on my dipstick when fully warmed up, idling, and on a level surface, is at about the half way mark, BUT, when idling, the oil guage reads all the way to the TOP of the guage... When I'm on the gas however, the guage reads right at the half way mark.
I filled it up with 9 quarts initially and after a drive was about 25% up from the low mark, so I put another quart in it. In fear of over filling the oil, I drained about .3 quarts.
Is this behavior normal? Should I be concerned if my oil guage is reading that high, but my dipstick is reading normally?
Rennlist Member
Joined: Mar 2012
Posts: 17,250
Likes: 2,219
From: SoCal
Use the dipstick, just ensure you're sliding it in fully. Car warmed up, thermostat open (feel the side pipes), at idle. Read it after a minute of idle. Middle of dipstick, no more, I like about 1/3.
The gauges on the 3 air-cooled cars I have/ had are spot on with the dipstick. Likely your tank sensor has gotten bent or out of calibration.
When not at idle the oil moves from the tank to the engine, that's normal behavior on a dry sump engine.
The gauges on the 3 air-cooled cars I have/ had are spot on with the dipstick. Likely your tank sensor has gotten bent or out of calibration.
When not at idle the oil moves from the tank to the engine, that's normal behavior on a dry sump engine.
Thread Starter
Advanced
Joined: Apr 2018
Posts: 83
Likes: 8
From: TX
Use the dipstick, just ensure you're sliding it in fully. Car warmed up, thermostat open (feel the side pipes), at idle. Read it after a minute of idle. Middle of dipstick, no more, I like about 1/3.
The gauges on the 3 air-cooled cars I have/ had are spot on with the dipstick. Likely your tank sensor has gotten bent or out of calibration.
When not at idle the oil moves from the tank to the engine, that's normal behavior on a dry sump engine.
The gauges on the 3 air-cooled cars I have/ had are spot on with the dipstick. Likely your tank sensor has gotten bent or out of calibration.
When not at idle the oil moves from the tank to the engine, that's normal behavior on a dry sump engine.
Was concerned because before the oil change, the guage and dip stick readings were correlated (guage would lower when on the gas, but still show almost half way mark) but now when idling, it's all the way full.
Anti-Cupholder League
Joined: Aug 2003
Posts: 3,933
Likes: 118
There are 2 ways to measure the oil level: the dipstick which is more accurate, and the gauge. No matter which one you use, the dry sump system requires that the engine be warmed up, at idle, and level.
The oil gauge is of no value when driving, etc. (and few will attempt to check the dipstick while driving).
The sender for the gauge has a bent arm on it and the angle of the bend can be changed to make it dead accurate. Mine runs ~ 1 Qt. high and I may change it someday.
The engine will run just fine with a fairly low oil level. The Oil Pressure Gauge is the most important one. If it has good oil pressure, don't worry.
Weird oil level gauge behavior can be caused by bad grounds, a loose mount in the side of the tank, the sender scraping on the side, low voltage, poor sender connections, etc.
Thread Starter
Advanced
Joined: Apr 2018
Posts: 83
Likes: 8
From: TX
Thank you for the help guys.
This begs another related question. How do I know what is "good" oil pressure?
I'll need to confirm, but I think at idle at cold the gauge reads 1.5
When I'm on the gas going over 3K RPM, it hovers right under the 4.
At what numbers should I be concerned about?
This begs another related question. How do I know what is "good" oil pressure?
I'll need to confirm, but I think at idle at cold the gauge reads 1.5
When I'm on the gas going over 3K RPM, it hovers right under the 4.
At what numbers should I be concerned about?
Trending Topics
Team Owner
Joined: Aug 2005
Posts: 28,462
Likes: 1,631
From: Cambridge Ontario Canada
cold im pegged .. but depends on your definition of cold ... on my cold CIS is running higher idle so definitely pegged ...
on highway i would say 4-5 for me ... anything else i have not really noticed as no lights came on.
on highway i would say 4-5 for me ... anything else i have not really noticed as no lights came on.
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
9 Vehicles Porsche Helped Engineer that Aren't Porsches
Verdad Gallardo
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner
Joe Kucinski
This Builder Is Turning Heads With Its Slantnose 911 Creation
Verdad Gallardo
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Thread Starter
Advanced
Joined: Apr 2018
Posts: 83
Likes: 8
From: TX
I went on a 2 hour rally a couple weekends back. Usually on the high way it hovers around the 4, but towards the end of that rally, it was hitting the 5 mark when my engine was over 3.5K RPM. It was hot that day, though.
Rennlist Member
Joined: Mar 2012
Posts: 17,250
Likes: 2,219
From: SoCal
That's fine. Rough rule of thumb is about 10 PSI / 1 bar per 1k RPM