oil level guage went crazy

[leverpuller]

yesterday while driving home,I noticed my oil level gauge bouncing up and down slightly. normally its down at the bottom but once the motor warms, the car's on level ground, the guage reads the same as the dip stick. Yesterday the meter bounced alittle the pegged at the top. turning off the key drops it down and turning the key on peg's it again... any idea where I should on this problem?

[Monza_dh]

Mine is the same way. check the oil sending unit (?) you may need a new one or just clean off the connections. Its located on the oil tank behind the drivers side rear tire. My rubber cover fell off and so I need to buy a new one. Waynes book has a chapter on it.

heres a post:

Erratic needle - Oil Press Sending Unit or the Gauge?


Good luck.

[porschefool]

Meh. Those things are junk to begin with. Check/clean all connections, then learn to ignore it altogether...

All while obsessively checking the oil properly, of course!

[theiceman]

This is what my doa sender looked like :

http://vids.myspace.com/index.cfm?fuseaction=vids.individual&videoid=1202081427

if you disconnect the sender it will peg, mine was due to the wiper moving off the the rheostat in the sender. After I replaced it again it works perfect and is very accurate.

[boxster03]

maybe worn out sender but before you get a new one check the ground and positive connections at the sender located behind rear wheel well passenger side. lots of dirt and road junk tossed up there. i had the same problem and it was a lose ground and lots of grime. a good cleaning and tighening and it stopped bouncing around. as was mentioned best to check oil via the dipstick and not by the guage although they should be fairly close.

[2.7RACER]

Porschefool,
Would you please explain your comment "these things are junk to begin with".

[porschefool]

No problem. It's a well known fact that these gauges are not to be trusted,
and, as Wayne mentions in the "101" book, the oil level gauge is "mostly useless" and if you are not idling on level ground the gauge reads artificially high or low. I have a hard time believing that Porsche would actually go to the trouble of putting "junk" in our beloved 911s, but there's no way I'm going to trust something like that to make what is arguably the most important measurement on my engine.

It's nice to not have it pegged (or dead) but to me it's just filler...
Wish I could put a voltmeter in that spot!

[T77911S]

Originally posted by porschefool
No problem. It's a well known fact that these gauges are not to be trusted,

I have a hard time believing that Porsche would actually go to the trouble of putting "junk" in our beloved 911s, but there's no way I'm going to trust something like that to make what is arguably the most important measurement on my engine.

It's nice to not have it pegged (or dead) but to me it's just filler...
Wish I could put a voltmeter in that spot!

come on. you have got to be kidding. im more concerned about temp and pressure. these cars hold 10 quarts of oil. the min to max line is what, 1 to 2 quarts. you think i am worried about driving with it at or below the min. in fact, i go through less oil if DONT keep it at the max level. i put in 8 quarts after taking the motor out not long ago and it didnt even register on the dip stick. thats with draining most of the oil out of the cooler (onto my floor of course). not to mention how much was left in the loop cooler.

if you know how to use the gauge it is very useful. i know that when my oil is half way between min and max, my gauge reads just a little over mid way. if my gauge reads ANYTHING i know i have plenty of oil.

[theiceman]

Mine is in fact very accurate, when I am idling when hot full is full and red is add according to the dipstick. I of course use the dipstick when checking but the guage works great.

[JP911]

Porschefool-
I believe that you can have a volt meter installed in that spot. Do a search, but Palo Alto Speedometer and North Hollywood Speedometer do all kinds of custom work on Porsche and other VDO gauges.

[2.7RACER]

Porschefool,
It's a well known fact the oil level gauge is the least understood gauge on the dash.
Since Porsche 911 motors are dry sump design oil is checked differently than most cars.
The gauge should only be read when your car is up to temperature, stopped on a flat surface and idling. Same as dipstick.
I have a 30 year old Porsche as well as a 22 year old Porsche. Both gauges work exactly as designed.
It is always a good idea to compare the dip stick and the gauge and believe the gauge first.
Porsche engineers built this gauge to keep us informed without the need to get our hands dirty.
Porsche does not make junk, sorry.

Edit: should read believe the dipstick first.

[porschefool]

I'm well aware of the proper technique required to check oil level....
and have been nearly obsessive about oil levels on all of the various P-car models I've owned.

Are you telling me you're more inclined to trust some cockamamie gauge setup than a stick that ACTUALLY CONTACTS THE OIL?

I love getting my hands dirty.. but don't have to when using the dipstick.
Again, my point is that there is nothing wrong with having a gauge for something, but when you can eliminate all electrical variables and physically look at the level on a stick you are always better off.

Oil is everything, as we all know, and the more accurately we can read the press/temp/level, the more we can relax and enjoy the drive.
Just my .02

[T77911S]

like i said, these cars hold 10 qrts+ of oil with a remote oil cooler. the only way i am going to run out of oil is if i get a hole and all the oil leaks out while i am driving. i have experamented with the oil gauge and dipstick levels enough to understand what the gauge tells me. one thing that has always impressed me about porsche is their advancement in technology. how many other cars had an oil level gauge in the 60's?
i have stopped filling mine to the "max" level. it seems to use more oil when i fill it up. if i keep it between the min and half full point, i use less oil. when you fill it, i think you tend to get more blow-by.
when my oil gauge doesnt move, then i go check the dipstick.
if you get too low, your oil temp will be the first indication.

[2.7RACER]

You are going to love this. From Porsche Boxter/S 2005 tech manual.

Oh, by the way my response regarding always trust the gauge first was a typo, shoud have said always trust the dipstick. So we aren't so far apart after all.
I don't have info on the new 997's regarding an oil dipstick. I suspect it has been deleted as well.
The point here is the oil level gauge operates similar to the fuel level gauge which we all seem to trust. When used as designed it is useful.

Edit: confirmed the 997 lacks an oil dipstick as well.