Pelican Technical Article: Oil Level Sender Replacement Wayne R. Dempsey
Time: 1 hr
Tab: $60
Talent:
Tools:
Socket set
Applicable Models:
911 (1965-89) 930 Turbo (1975-89)
Parts Required:
New Oil Level Sending Unit, gasket
Hot Tip:
Never depend on this gauge for accurate readings always check the dipstick at idle when the car is warm
Performance Gain:
Semi-accurate oil level readings
Complementary Modification:
Oil change
This article is one in a series that have been released in conjunction with Wayne's book, 101 Projects for Your Porsche 911. The book contains 240 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Porsche 911 owner's collection. See The Official Book Website for more details.
Check out some other sample projects from the book:
If your oil level readings in your dashboard gauge are a little off, then it might be time to replace your oil level sender. Quite possibly the most dangerous part in the car, the oil tank level gauge is indeed mostly useless. Its measurements are only accurate when the car is warm and at idle. At all other times, the gauge will read artificially low or high values. Some of the times the sender or the gauge will stick, leading to more false readings. In general, the safe rule is to only check the oil using the dipstick located in the filler neck of the engine compartment. The oil should only be checked when the car is fully warmed up, and at idle.
If your oil tank level gauge is pegged at full, then you probably have a problem with the sender. Replacement units are relatively inexpensive at around $60, and the process of installing the new unit is quite simple.
The oil tank level sender is located on the outside surface of the tank, which is located in the rear right fender of the 911, behind the wheel. All 911s had their oil tanks in this location except for the 1972 911, which had it in the front. The sender unit is held on with 5 small nuts that need to be removed. Its a wise idea to clean the area of any dirt or debris that may have been flung up into this area from the tires. When you remove the sender, you dont want any dirt falling into the tank.
The sender is an obscure shaped unit, and may require some wiggling in order to remove it from the tank. The new one should be installed in the same orientation as the old one. The sender can only mount on the holes one way, so you cant really mess up the rotation. Make sure that you use a new gasket, and tighten the nuts snug.
If after installing the new unit, your gauge is still reading irregularly, you may need to replace the gauge. Unfortunately, the oil level gauge unit is not available as a separate unit: you have to purchase the entire gauge as a replacement. The old gauges simply pop out of the dashboard, and the new ones can be pushed back in after all of the electrical connections are reattached.
Figure 1
The brand new oil level float is a bizarre looking part. Its shaped so that it can barely fit inside the hole in the side of the tank. Installation requires a bit of maneuvering in order to place the sender inside.
The sender is accessible from the outside of the tank, looking in from the rear wheel fender well. The primary signal wire is connected to the center of the unit, and a ground is connected to one of the mounting bolts on the unit. Make sure that you dont drop any dirt or debris in the tank when you install the new unit.
If after youve installed the new unit, your gauge still isnt working, then its likely a problem with your actual dashboard gauge. You can only replace the gauge as a unit. The old ones simply pop out of the dash and can be replaced with a brand new one after reconnecting all the wires in the rear.
