Fuel tanks, is there difference betwwen 2/4/touring?

[tomislav]

As per the title really, my mates got a 325i touring on a f reg and needs a fuel tank that isn't full of shit with a hole in it.

Are there any differences between the 3 door, 4 door and touring tanks?

Thanks,

Tom

[Brianmoooore]

Small engined saloons have a 55 litre tank. Everything else (facelift at least) has a 62 litre tank, which is what you need.
It's possible to fit the 'wrong' tank, if that's all you can get, but you'll need the matching fuel pump and fuel gauge, and will have to make alterations to the wiring and plumbing.
55 litre tank is identifiable by a small bore pipe between the two halves at the bottom and only has one pump fixing hole on top, and the 62 litre tank can be recognised by the fact it has two holes on the top and no pipe linking the halves.

[greg124]

Also on the 55 litre tank the bottom is about 3 inches lower on the drivers side than the passenger side, whereas the two sides are about the same level on the 62 litre.

[tomislav]

Ah, this might explain why my 325 converted 318is fuel gauge is all wrong, the guy i bought it off said something about the fuel pump/tank etc, brian, can you shed anymore light on this?

Also, mine is an H reg 318is 2 door originally, so which tank should be fitted?

[Brianmoooore]

AFAIK, the iS left the factory with a 55 litre tank, but neither the tank or the fuel gauge should have been touched when carrying out a 325 conversion. All that should have been done was to change the four cylinder coding plug on the front of the instrument cluster for a six cylinder one, to make the rev. counter read correctly.
It's possible, however, that the 325 cluster was fitted complete, which will then give you the wrong fuel gauge. If so, the gauge should read full when the tank is full, but only drop to half when the tank is empty.

[greg124]

Mr Mooooore, are you sure that all 'small engined saloons' were fitted with the smaller tank?
I only ask as my H reg 316i has had a 62 litre tank for most, if not all of its life...

[Brianmoooore]

Mr Mooooore, are you sure that all 'small engined saloons' were fitted with the smaller tank?
I only ask as my H reg 316i has had a 62 litre tank for most, if not all of its life...

Checking with the ETK, it shows 316i and 318i models "only applies to edition '90 January -" as having the larger tank.
I've no idea as to what "applies to edition" means.
Curiously, the iS only shows a 55 litre tank.

[greg124]

Hmmm! Probably means something along the lines of 'from Jan '90'. Maybe BMW were running out of stock of the smaller tank for a model which was due imminent replacement (saloons, anyway), and wanted to keep inventory down.
Maybe the 318iS retained the smaller tank to keep weight down...

Conjecture - not as compelling as conspiracy theory!

[Brianmoooore]

Plenty of things in the ETK list ' - a date' for a part and then 'a date - ' for a different version of the same part. It's the "only applies to addition" bit that's unique to this entry.

[greg124]

It would be interesting to find out what that unique entry means

[Brianmoooore]

'Lux' models were introduced in 1990. Is yours a 'lux'?

[greg124]

You didn't think I'd be slumming it in a poverty spec car...

[Brianmoooore]

'Lux' is the probable answer then!

[greg124]

sounds like we've got to the bottom of another anomalie.