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kemestry
07-23-2007, 03:31 AM
Okay, so my gas gage decides to stop working and its frustrating me to no end because I drive all over the map and I hate having to estimate.
I was wondering if it is the gauge or something else because the gas reading on the OBC is playing around as well.
Whats happening is the gauge is flying all over the place but mostly being stuck between 40 and full and the reading on the OBC is the same.

I'm looking for any assistance 'cause this is driving me nuts. :mad:

Soldo
07-23-2007, 05:56 AM
Just outta curiousity, what gas (company) are you using?

I had the same problem with my 325 after i began using Shell gas. Apperently the fuel has a lot of a certain chemical (can't remember which ingredient) and it caused my fuel sending unit to get all ****ed up.

Also, you should always pay attention to your fuel mileage, it can help a lot in times like this or even to help diagnose other problems!

kemestry
07-23-2007, 11:10 AM
Thanks for the response.

Yeah, I agree with you, in fact I had just stated to pay attention to it because I have a feeling I might need to change my o2 sensor.

Anyways, back to the gas issue, I believe that I did use Shell before it started getting messed up. Weird. And why is that? And is there a way to fix it?

BTW, what does the average e30 get p/L for comparisons sake?

Thanks again for the quick response.

dgmorr
07-23-2007, 11:28 AM
I get ~ 10L/100km with my 2.7i and a fairly heavy foot around the city.

Keep 2L of gas in a container and see if your fuel light still works. My gauge is out, but my light still works.

kemestry
07-23-2007, 11:31 AM
e30's have a light!!??!?!! shit, I thought it was just the red line that was the warning. Where on the cluster is the light located because I need to see if it is working.

EDIT* does anyone know where I can get a manual for an '89 325i online in PDF format or something? Or even get a hard copy version? It woud be nice to have.

Thanks again guys

El Gato Liso
07-23-2007, 11:33 AM
ya my guage is gone too
i was on my way home from ajax to brampton thinking the car had just over half tank...little did i know it was empty and shut off on me.

i too am wondering how this problem can be dealth with

supernaught
07-23-2007, 11:35 AM
its just to the left of the redline. I can get more thand 80kms after my light comes on, never ran it dry tho so not sure

kemestry
07-23-2007, 02:02 PM
nice ... i went outside and spotted the light. Like I said, it never came on though and according to the OBC I've been down to as low as 3.5L chickened out and headed to the gas station. At what point will the light come on??

Oh, and after doing some research, I've decided to take out the cluster and apparently there is a bolt on the back of the gas and taco that sometimes comes loose. I'm going to fish around and let you guys know.

Thanks

dgmorr
07-23-2007, 03:31 PM
Just check the sending unit under the rear seat. There should be a harness with 3 pins. Just short two of them (i forgot which ones), your warning light should come on. This will tell you if the circuit is working....the rest...who knows. You can pull it out and replace the entire unit for about $150 new.

I've driven about 55km after the light came on and chickened out.

Soldo
07-23-2007, 06:30 PM
Ya, when the problem occured to me i was told that my sending unit had to be replaced, and i should switch to using anything BUT Shell. So i did that, and the problem fixed itself temporarily but the sending unit was too shot since i was using shell for more than a year.

I've been told that this problem is common with some cars when using Shell gas!

FuryriderX
07-23-2007, 07:40 PM
my gas light comes on when i have EXACTLY 10L of gas left in the tank. this happened a few times in a row, so i know its not a fluke. so you should be able to get around 80kms after the light comes on.

could also be a bad ground in the cluster itself, you can take it out and apart and have a look-see, clean the contacts, couldnt hurt.

qimis
07-23-2007, 08:52 PM
Mine's dead too ... Not sure if it's because of the Shell thing or not, I sometimes go to Sunoco or Shell. And no luck tightening that grounding nut behind the cluster. The warning light used to come on before the engine swap, but completely after the swap.

e30_kid89
07-23-2007, 09:06 PM
*uzi* all E30 gaz gauges.....and peoples dont run your tank empty your fuel pumps wont like it.

dgmorr
07-23-2007, 10:23 PM
my gas light comes on when i have EXACTLY 10L of gas left in the tank.

How do you know it was exactly 10L?

FuryriderX
07-24-2007, 03:28 AM
because i know the tank holds 63L, and i put exactly 53 in it 2 times in a row, and 54 the third time, after the light came on. i went almost directly to a station afterwards.

dgmorr
07-24-2007, 11:23 AM
because i know the tank holds 63L, and i put exactly 53 in it 2 times in a row, and 54 the third time, after the light came on. i went almost directly to a station afterwards.

Nice. I never used to fill up my tank, I'm just weird like that, so I never knew.

dazzkid88
07-24-2007, 09:44 PM
*uzi* all E30 gaz gauges.....and peoples dont run your tank empty your fuel pumps wont like it.
Yea I learned this the hard way...*mumble*

static
07-25-2007, 05:11 PM
i am another victim of shell gas messing up my gauge

anyone actually fixed the problem? how much is the part(s)?

kemestry
07-27-2007, 02:44 AM
Hey, I've been doing some reading and I found out that the batteries on the SI board are a culprit of this gas gauge issue as well. I looked into changing the batteries and there are 2 kinds: AA niCad and 1/2 AA Lithium [Sanyo CR14250SE 3.0 Volts / 850 mAh]. I unfortunately ended up with the 1/2 AA lithium version of SI board.

So I pulled out my cluster, pulled out the SI board and low and behold, the batteries are dead [well one is and the other is okay]. So

I found on place in Scarborough / Markham on Gorden Baker called electrosonic and they have to order them. I was wondering if anybody knows where I can get my hands on these soon because this might be the solution for a lot of us.

Engin33r
07-30-2007, 08:32 AM
... I was wondering if anybody knows where I can get my hands on these soon because this might be the solution for a lot of us.

Here's a Solution that'll work if you can't find the 1/2 AAs, or they suck.

grab an old kids toy that has electronics, or just go to radio shack and buy a AA or AAA battery holder. Make sure that the holder runs them in series (to get your 3.0V)

Solder on the 2 wires from your holder to the 2 points on the board where the 1/2 battery would go, insert your batteries, and you're done.

Of course this is a hack,*shiner* but you know that in the future you won't have an issue of replacing batteries, and second the batteries you'll buy at the store will most likely last you longer as well. My iS (just bought of Docherty) has the same issue which I'll tackle in the near future.

--Edit--
Get the double holder if you need 3 volts, and the single if you need 1.5V (AA varient SI), or find a 3A AA and use a single. Many Many options

BMW325BMW
07-30-2007, 09:28 AM
for those of you with the 12 buttone OBC, I cant remember if it is the 1000 and 1 button or the 100 and 1 button. Try both ways, but if you press them simultaneously one will give you the software version and the other will give you how much gas is left in your tank. Pretty accurate too. I would get to between 5 and 6 liters and my light would come on every time, all the time.

Engin33r
07-30-2007, 01:29 PM
Here's a Solution that'll work if you can't find the 1/2 AAs, or they suck.

grab an old kids toy that has electronics, or just go to radio shack and buy a AA or AAA battery holder. Make sure that the holder runs them in series (to get your 3.0V)

Solder on the 2 wires from your holder to the 2 points on the board where the 1/2 battery would go, insert your batteries, and you're done.

Of course this is a hack,*shiner* but you know that in the future you won't have an issue of replacing batteries, and second the batteries you'll buy at the store will most likely last you longer as well. My iS (just bought of Docherty) has the same issue which I'll tackle in the near future.

--Edit--
Get the double holder if you need 3 volts, and the single if you need 1.5V (AA varient SI), or find a 3A AA and use a single. Many Many options


Apparently, this isn't an original idea. Google found me this when I looked up the problem today.

-_-_-_-_-_-_-_

inside the instrument cluster (once you take it apart you will find a small circuit board plugged intot he main module, ...this is called an SI board (service interval)

the SI board works off rechargeable batteries soldered onto the main instrument cluster. You can remove these yoruself if you are handy with a soldering iron, and replace with either nimh or nicd (depending ont he type originally fitted to the car)

what happens is that after 10 years the si board batteries are no longer able to hold a charge.

the symptoms are as follows:
rev counter doesnt work
fuel gauge erratic
temp gauge erratic
servie indicator lights will not extinguish (the reg-->orange-->green lights) even after a reset.

instructions for taking the clocks out and replacing the batteries can be found in many places....here is one of them
http://e30m3performance.com/maintenance/SI_Board/SI_Board.htm

if you can do it yourself it shouldnt cost more than the cost of the actual batteries themselves.
here is a picture of the offenders
http://e30m3performance.com/maintenance/SI_Board/Step_10.htm
the top board has two RED batteries (AA size)..the lower board is an aftermarket piece with a smaller coin size battery. All you have to do as a DIY is remove the red batteries and replace with suitable alternatives. The batteries have solder tabs on them, so if you can get replacements with solder tabs...great...if not, get a little black plastic battery holder, put some wires on the + and - and run them to the correc tplace ont he circuit board.

I bought a battery holder and two nicds for mine, then ran wires from the main board to the kickpanel so that the batteries are more accessible should I need to do it again...instead of stripping the whole dash I just remove two screws holding the kickpanel in and replace the batteries

-_-_-_-_-_-_-_

Thread can be found here:
http://techies.co.za/phpBB2/viewtopic.php?p=10499&