fuel gauge off

[E30nate]

i noticed that after i changed my cluster on my 87 i, that the gas gauge is about a half tank off. any reason for this, or is it just a coincidence that the level sensor messed up at the same time?

[jlevie]

An 87 is a bit of a weird beast and has parts that aren't used on earlier or later production. Replacing the cluster with one from a later model (the most likely case) will result in a gauge that is off by roughly one half tank. Meaning that the gauge will indicate full, but not go below about a half tank. At this point I'm not sure if this problem is in the gauge itself (the part numbers are different) or in the main PCB (likewise on the part numbers). If I ever get sufficiently motivated I'll figure out which it is.

[E30nate]

thats probably what it is. the cluster is out of a 90. i have one from a 87 that i picked up, so i will swap that in and see if it fixes it. thanks for the info.

[Kilawin]

Whats the new cluster from. Interested in selling the fuel gauge or trading for one from a 325is. The one in my 318is is dead. The 325is guage is off too when I plugged it in my car.

[E30nate]

the cluster is from a 90 325i. the 318is has a different coding plug, but that usually only effects the tach. i have a few extra coding plugs if you wanna try those. if you pay for shipping i can ship one or two to lathrop.

[Kilawin]

I did put my coding plug in the new cluster. Fuel gauge is still wrong.

[E30nate]

ok. i dont know if it will fix anything, but i will sell you the cluster if u want it.

[Kilawin]

No thanks. We basically have the same one.

How big is the fuel tank in your '87? I think thats why the 318is is fuel guage specific. It has a smaller gas tank.

[E30nate]

i think its 14 gallons. i filled up last night with the light on and it took a little over 13.

[netcsk]

I would try to fill the car up and adjust the gauge. I changed the gauge out on mine at some point and had to do the same. It reads correctly now.

Just take the gauge out and push the needle. It will resist when you're actually adjusting it. Push it the same amount you want it to offset.

[Kilawin]

i think its 14 gallons. i filled up last night with the light on and it took a little over 13.

yea same as mine. i believe the other fuel tank size 16 gallon

[gearheadE30]

Mine is 12.7 according to the manual iirc. I have an extra fuel gauge that I believe was ordered for the 318is, but I've never used it. PM me if you want it.

[gmiller5m]

i replaced the cluster in a 90 325i w/ one from a 91 318 and the fuel gauge was off. Coding plug only affected the tach. I had to switch the 325i fuel gauge back into the 318 cluster to get the fuel gage to read right in the 318 cluster.