Oil Gage Reading

84porsche · 84porsche's Garage

I have been trying to get used to the oil gage. When I am driving it seems like it is in the red most of the time but when I stop it is in the white area of the gage. I have asked around but I wanted to know if the oil level should be near the top or in the middle when the car is at temperature and idling on level ground. I don't want to cause damage to the car by being a quart short. Is it normal to be adding oil every couple of weeks in between oil changes??? and should I be changing the oil every 3,000 miles - every time I change the oil - it is still very clean??? Any help would be appreciated. Thanks.

masraum · 10:42 AM

When the car is up to full operating temperature and the car is stopped on level ground and has been idling for 10-20 seconds then you should probably see the needle in the middle of the gauge. As soon as you touch the gas it will go to red. Don't worry too much if it's not on the gauge under normal circumstances. half of the time mine is at the bottom of the gauge. Since we have nearly 14 quarts of oil being 1 or 2 low isn't a problem. You won't notice a problem until you are 4-6 quarts low, and even then you would probably be ok as long as you aren't running really hard.

having to add oil isn't a big deal, most of our cars burn leak oil so we generally have to add from time to time. That's not a problem until the usage gets really extreme.

Clean oil is a good thing, it's cheap insurance. I'd keep changing my oil if I was you.

pwd72s · 01-05-2004, 10:40 AM

When the car is up to temp, idling on level ground. That's the only time the oil level gauge is close to accurate. That's also the time to trust your dipstick, which is the true accurate way to check oil. Shoot for a level 1/2 way between the 2 hash marks.

Hugh R · 01-05-2004, 01:32 PM

Owners manual says don't read the gauge when your running, only idling, warmed up and level ground.

geof33 · 01-05-2004, 02:57 PM

Also, it won't read anywhere near correct until you reach a temp in the 200 range. If you watch the gauge you will notice it reading higher when warmer. That's why it's critical to check your oil at FULL warm up. Temp gauge at the first black mark (220 or so).

diy83sc · 01-05-2004, 03:11 PM

The way I read mine is by looking at the oil level and temp at idle on level ground. As the temp increases, so does the oil level. It is important that you only add oil when the engine temperature is at the half way mark (200?) because the oil expands when it gets hot. Otherwise, you risk overfilling.

looking at the gauges,

cold level \ / temp

hot level -> <- temp

real hot level / \ temp

sorry for the stick graphs...

Tony

304065 · 01-05-2004, 03:20 PM

And when you are checking the oil don't get anything caught in the rotating fan. A gas station attendant's tie came dangerously close to being ingested. And THAT would have ruined his whole day, to say nothing of my concours potential.

rburn · rburn's Garage

What are the two hash marks on the dipstick? I mean is the 1st 1 qt low? and the 2nd 2 qts? etc

Also the oil temp on my car in 50 to 60 degress (F) driving weather rarely goes over the 1st white tick or 1/4 unless idling for like 15 minutes. what does each white tick respresent?
1/4 = ?temp
1/2 = ?temp
3/4 = ?
and then the red... what is the temp?

Has anyone every tried to trouble shoot the oil level sending unit?
I believe mine to be off, but the bentley manual says if you pull off the sending unit main wire and ground it and turn key on it should max gauge, well mine sits at 1/4 when connected and car not started and then when i disconnect main wire to level sensor then turn the key on it maxs the gauge and when i ground the wire as the manual says it reads empty. I wonder if either my guage is malfunctioning or the bentley manual is backward.. I pulled the gauge and took off the grn/wht wire and took it off at the sender unit and i checked for continity correctly (wire is good from sender to gauge) and i checked the other wire to the sender and it's grnd and tests good for that. Is the sender level when it's low resistance mean oil is full and gauge maxed?

Thanks for any info.

ischmitz · ischmitz's Garage

Lot's of people advise to not even trust the oil gauge at all. It's the most unaccurate instrument in your car besides the clock.

The marks on the dipstick are about 2 quarts apart. Even at the lower mark there is enough oil in the engine/tank to ensure proper lubrication (feed to the oil pump pressure side). If you overfill, you will ingest the exessive oil into your intake and your car will smoke like hell. You'll run the chance to ruin your cats. It's an easy mistake. These engines are dry sump. If they sit oil will seep into the engine block. So never measure without the engine running. And when the car is not at operating temp you could easily misread the dipstick by two quarts. That's how much termanl expansion does.

Learn how much oil your car consums per tank and read the dipstick every time you fill her up. If the oil gauge reads the same, fine. But a stuck oil gauge pretending there to be sufficient oil while there is not enough won't pay for costly oil starvation damages to your engine.

Ingo

Wil Ferch · 02-12-2004, 06:22 AM

Au contraire ! ...
The gauge is VERY accurate...it accurately depicts the "ups and downs" of the tank level as you drive. Completely different concept in that it's not "appropriate" to read the gauge while driving... true. The time to take a level measurement is when all 3 are in-play:
- level ground
- idling...say 800-880 rpm...faster will dip the gauge
- 190 degF temp.

Hi/ low dip stick is about 1.75 quarts or so.

Do a search on this..it's been gone over before. I've posted a number of times what the hash marks represent in terms of temps, others have posted also on the calibration temps marked on the VERY edge of the gauge if you look WAY OVER inside the gauge.

Also, don't ovefill. Good point to fill to mid mark on stick. Too full and you overflow into the intake tract...causing "apparant" hi oil consumption. You then tend to check...add...and it starts all over again !

---Wil Ferch

rburn · rburn's Garage

hmm, well i found it

- lowest white block 60 degC ( 140F)
- next up white mark, 90 degC ( 194F)
- next white up, 120 degC ( 248 degF)
- lower part of next up red block, 150 degC ( 302F)

I finally had to search for "temp" and your name as author, and sort down until i found it.

I need to play with this board abit to see what my default search return is etc... to pick up on all the good stuff!

Thanks

http://www.pelicanparts.com/gallery/rburn/

rburn · rburn's Garage

Oh yes.... Did anyone happen to pull the fuel/oil gauge and
pull the grn/wht wire and turn key to on position and have gauge max out? I'd like to verify that the manual "bentley" is right or wrong.... as they say if the grn/white is grounded then it should max the guage ... i do not get this.

http://www.pelicanparts.com/gallery/rburn/

Danskman · 02-12-2004, 02:25 PM

Yes, be absolutely sure your car is completely warmed up before checking the oil level on the dipstick. If it 's not warm, then you might think the oil is low, when it's really not, and add a quart or so, causing humungus clouds of smoke and your heart to pound out of your chest, sending you crying to your dog, thinking you just launched your 911 motor, dollar signs flying through your head.