E30 316i touring rattling when revving and Bad MPG HELP!

[sethfine]

I just bought an e30 316i and whilst driving it home from london to bournemouth I realised there was a ticking / rattling sound when revving. At 3500 revs it got real bad then at about 3650 it went back to the normal rattling. The other issues which could be linked are that I was getting ultra bad MPG most of the journey. I was struggling to get over 14 and my fuel gage was very erratic starting at half on what i was pretty sure was a full tank and for about 20 mins it went up to full. either way I almost rinsed a tank in 100 miles which isn't right. Could I have a problem with fuelling? if so what could this be, is it a common problem with these cars, and what should my MPG be?

The car was servised by BMW very recently and has almost a years MOT.

[TPS]

Does the car rev. over 4k?

[Grrrmachine]

For the rattling noise, read this:

http://www.e30zone.net/e30zonewiki/inde ... _Over_5000

For the fuel economy, best test is to brim the tank then drive it till the orange light comes on the fuel gauge, and then see how many litres it takes to top the tank back up again. That's the only way to ascertain whether you've got an economy problem or a fuel gauge problem.

[Brianmoooore]

Before you brim the tank, I'd make sure the tank isn't leaking. There are plenty of E30s out there whose fuel consumption rises dramatically when their tanks are more than a third full.
What colour is the tip of a spark plug?