What fuel tank do I have and why is it so small!?

Post Wed Apr 20, 2016 7:59 pm

I have a 1989 320 cabriolet, and my fuel tank only holds about 30/35 litres. It now leaks so I will be looking to replace it but e30 zone wiki suggests there were only 55 and 63 litre fuel tanks. Why is mine so damn small!? Will other tanks fit on my car?

Thankyouplease

Post Wed Apr 20, 2016 8:56 pm

That should have a 63 litre tank, and if it can only be filled with 30/35 litres, it suggests that the LH saddle of the tank isn't being used.
Alternatively, how do you know that it's empty when you fill it? Have you driven it until the fuel light comes on?

Post Wed Apr 20, 2016 8:59 pm

I've driven it to below the empty mark. Cant remember if the low fuel light works or not. The needle range from below empty to totally full is £35 approx. Would be very surprised if there was another £35 hiding under the tank empty mark. Is there two fuel level sensors, is it possible one isnt working and has thrown my gauge out?

Post Wed Apr 20, 2016 9:04 pm

Brace yourself if your are going to change your tank!!!one of the worst jobs I've done on
My e30! But if you have access to a ramp don't let my comments stop you. Just prepare for the possibility of changing many hoses and other bits as you go along.

Post Wed Apr 20, 2016 9:06 pm

Chances are that your instrument cluster has been changed for one with a 55 litre gauge in it.
This will read empty when your tank is half full.

Post Wed Apr 20, 2016 9:43 pm

What tank would a 316 coupe have, as i fitted 4 pot clocks from one (temp gauge issue) and the fuel gauge seems to read the same

Post Wed Apr 20, 2016 10:06 pm

316 2 door saloon would have a 55 litre tank, and a gauge to match.

Post Wed Apr 20, 2016 10:34 pm

Think you've found my problem then haha! Thanks for the help guys. What cars had a 63l tank, so I know what clocks to get?

Post Wed Apr 20, 2016 11:17 pm

Generally speaking, the more desirable ones - all with more than 2/3 of an engine (except early stuff), and all tourings and cabs.

Post Fri Apr 22, 2016 9:14 am

Thanks. Will my low fuel light work accurately with the clocks I have, or will that be affected too?

Post Fri Apr 22, 2016 9:50 am

Low fuel switch is part of the RH level sensor, which is the same for both sizes of tanks, so the light will work as intended.
It WILL work, as well. In every case on here of members complaining that their low fuel light doesn't work, AFAIK, it has turned out that it was in full working order, and they just hadn't run the tank low enough.

Post Fri Apr 22, 2016 6:53 pm

Yep, my light came on when below the bottom of the gauge.
Nervy stuff