MACH993

I went for a drive and the needle wouldn't come out of the red when idling and on level ground. I'm thinking, 'ruh roh'! However, a quick check (actually it was about six times) of the trusty mile long dipstick, showed the oil level right where it should be...3/4 up the twisty section. The needle never did come out of the red during idle the rest of the day. The next day, after another drive, the little SOB (needle) was right back at 4 o'clock. Wtf? Later, to make me feel better, I read a kajillion posts on this same subject. Nonetheless, I feel compelled to add another for future perplexed first timers.

MielsOnWheels

Same experience with my oil level gauge- it never moves. I check my oil regularly with the dipstick and the car doesn't leave a drop of oil on the garage floor. I have added about 1 qt to it since I've had the car (got it April '12)

aarrow

As of last week, my oil gauge stopped working as well. The oil level on the dipstick is right on the mark.

I've driven 10k miles since an oil change in September 2012. Added no more than 1/4 quart - and not because the oil level was low, but in an attempt to make the needle move.

Mike J

As part of my oil change "service" I think i have calibrated a good 6 or more of these now. When someone comes into the shop, we discuss if the gauge reads low or high, and while the car is hot, we check it out. When doing the oil change, it's not that much extra effort to pull the liner and sensor, and bend the arm the correct way to put the gauge into the correct region, or at least where the owner wants it.

I am not sure why there is so much variance between different cars, but it's there for sure.

Cheers,

Mike

Hawgdriver

Mike,
I just changed the oil today and would have loved to have known this. Do you know of a DIY with how to do this? or can you snap any pics next time pls.

Cheers,
Matt

Mike J

Super simple - think i have posted this a few times.

The sensor is on the side of the tank, about 2/3 up on the back side. You get at it by removing the front wheel well cover on the right hand rear wheel. Remove the 6 nuts, and pull the sensor off the tank gently. The first time its out, the gasket will likely stick, so be careful, perhaps using a small screwdriver or prying tool. Once the gasket is separated, you can pull out the sensor a bit more, but it will not come out of the tank because the float needs some swing room to make it through the hole, but the line is not long enough. Its long enough to bend the arm to the float - much like a shut off valve for a toilet. If the gauge reads low, bend the arm so the float hits the oil earlier. If it read high, bend it the other way. I use two pliers to do the bending. Bend about 10-15 degrees the first time, push the sensor back in place, and tighten up the nuts. Not too much torque, just snug, like 7 ft-lbs.

Run the car and note or time what the gauge reads as compared to the level on the dipstick. If it needs more adjusting, then do it the next change, or you can calibrate when you want, the oil should be below the sensor opening. Keep it clean, you do not want any crap to get into the tank.

Have not posted this to pcarworkshop yet, but i am working a major revision (stay posted!!), so I will try to put it in there.

Cheers,

Mike

Steve Weiner-Rennsport Systems

If I might add,.........

Over the years, I've seen everything from burned up, destroyed engines due to insufficient oil and engines filled with oil right up into the ports & intake manifold (hydraulically locked), mainly due to folks who didn't learn to read the dipstick.

Based on some experience with these cars since 1974, I tell my clients that the dipstick is "The Gospel" and not to put a lot of stock in the oil level gauge.

Such advice might very well save someone's engine and at least, a LOT of aggravation.

vincer77

Mike/Steve, I have done this twice now. Both times, the gauge and the dipstick agree right after oil change, but after awhile, the guage reverts back to reading low. I thought maybe the rod returned to it's original shape, but on the second oil change, I pulled the sensor and the rod still looked bent.

Have you experienced this? Could there be something in the electronics that needs to be calibrated?

Mike J

Interesting, I have not seen this, but then again I have not explicitly checked afterwards that the calibration stays true. It seems to be OK on my car.

When you pulled it the second time, did you "recalibrate" or you left it?

Its a pretty simple system and I am not sure why anyone would put in the electronics an adjustment factor - that is weird. The sensor shows on the wiring diagrams as a variable resistor and feeds directly into the dash gauge - no electronics in between that I can see. The spec is a full tank is 178 - 192 ohms, and "idle" - not sure if that is empty, is 6 ohms. The gauge is actually a variable resistor to ground, the gauge is fed by the main power. Funny, we are not changing the circuits at all, the change is mechanical, so how would electronics know the difference between a full tank, or a half-empty tank with the float arm bent?

How much did it drift? Did you change brands/viscosities of oil in between? (just on the idea that the float will behave differently - very long shot..!).

Cheers,

Mike

Slow Guy

With photos

Mike J

I have done so many threads now I keep forgetting these things - thanks Bill!

vincer77

I will check the resistance this time. Thanks for posting the values.

It was reading approx 1/2 with 1/2 on dipstick. It now reads in the red and dipstick reads 1/2.

vincer77

Finally got to the oil change and checking the oil level sensor. Mine is reading 6 ohms empty and around 46 ohms all the way up. Seems like i have a bad sensor.

Also pulled a bonehead move. As I pulled the float out, I did not have it aligned well and the float pulled off the end of the arm and fell into the oil tank! Now what?

Used a magnet retriever, but I am guessing the float is made of stainless, so did not work. Next idea is to start filling it with oil and hopefully I can fish it out if the oil level is close to the opening.

Any other suggestions?

kjr914

A ladle? ....with a long string tied through the hole in the end, just in case!

Mike J

woops - yeah that is going to be a problem. If the oil is not in the tank, can you removed the tank? (that could be more trouble than its worth)... Not sure of the oil level when you fill it up, that that is what I would do....