fuel guage swap 318 to 320 - issues?

[milescook]

Read the wiki and some past topics, bottom of my fuel tank has a dent driver's side which may not help!

Tested the 2 senders on my tank, I have a 1988 320 so 2 door. I guesstimate around 10 litres of fuel left. I get 70 ohms on the ns and around 2 on the os. .. os sender knackered? I did replace the fuel pump 2 yrs back.

Also, I've installed 318 clocks with a working temp guage and rub counter (used my old 6 pot white plug) and showing less fuel than even before. Are they not compatible?

Cheers.

[bss325i]

There are two sizes of fuel tank fitted to E30's, 55ltr and 62 ltr and the fuel gauge has to match the tank as the smaller tank only has 1 sender as opposed to the larger tanks two senders.

Most 318's had the smaller tank but 318i Lux saloons had the bigger tank.

[Brianmoooore]

Both senders have a resistance that varies from close to zero to about 70 ohms, and the readings you get when you measure them in situ depends on the fuel level in that particular side of the tank, which is not necessarily equal.
Whether or not the fuel gauge in your 318 clocks is compatible with your tank depends on the type of tank the original 318i had. If it was 55 litres, then no, but if it was 62 litres, then yes.

[milescook]

Ok it wasn't a lux so I'm looking at the fuel guage swap then. I've seen th mentioned and sounds fiddly. Tricky job? What are the main pitfalls? Took my old clocks apart once and ham fisted didn't get them back together right.

[bss325i]

Very straight forward one the complete cluster is removed.

Just remove all the cross screws on the outside of the back of it plus one or two in the middle then the housing can be removed off the back to reveal the gauges. The fuel gauge is held in with a 7mm nut.

[milescook]

Cheers will give it a go!