Fuel system maintenance. In tank pumps?

The main fuel pump is located in the tank with the fuel level sender. It's a question of leave it alone until it goes wrong. Then fix it. If it is working as it should, no maintenance is required. Mike.

Understood. Is the sender usually accessible, like via an access point in the trunk?

Yes.

No. But if it fails it can be a PITA to get to. Some cars require cutting the carpeting to access the hatch above the fuel tank(s).

Just curious what the fuel filtration system / pump system

Filter is external.

I have a '94 525i SE E34. I'm fairly sure on mine it's accessed via a cover in the boot, but on some BMW's the cover is under the back seat squab. In my car it's never given any trouble, so I can't be certain without checking, of where it's fitted. Once the cover is removed, it's a simple job to remove the fuel tank sender and pump unit. Mike.

Check it yourself here

Sir Hugh of Bognor

The difference between men and boys is the price of their toys. Intelligence is not knowing the answer but knowing where and how to find it!

Hugh Gundersen snipped-for-privacy@h-gee.co.uk Bognor Regis, W.Sussex, England, UK

Thanks!

The link made me go through the drill, but here is an image of a 1994 E34 M50 525i fuel sender. Looks pretty standard:

Also, there are sometimes 2 filters and 2 pumps on cars. For my 1987 Volvo the fuel tank pump is the "pre-pump" with a sock filter. It sends fuel to the main pump and main filter under the car.

That's mainly why I was curious of this setup.

Jamie

Thanks!

The link made me go through the drill, but here is an image of a 1994 E34 M50 525i fuel sender. Looks pretty standard:

Also, there are sometimes 2 filters and 2 pumps on cars. For my 1987 Volvo the fuel tank pump is the "pre-pump" with a sock filter. It sends fuel to the main pump and main filter under the car.

That's mainly why I was curious of this setup.

Jamie

Earlier E34's have a similar system. 2 pumps. A transfer pump in the tank with the sender, and a main pump in te fuel line.. Mike.

Sometimes (quite often?) the senders fail because a wire comes loose or the contacts get dirty but they're easy to fix. Very often there are two senders in each half of the tank.

Now quit asking questions and go buy one!

LOL!

Quit asking questions and go buy one? (hee hee).

Well, I wish it were that easy. My wife insists at least ONE of my Volvos goes first. So, I'm selling the 1987 740 and keeping the 1985

240 battle wagon. Next, I want to sock away a couple extra thousand and try and find one a little above average.

Speaking of failing in-tank pumps - I hope BMWs are more simple because I have just put-and-pulled my 1987 Volvo one THREE times chasing gremlins. Now I have the main pump and filter off as well - up to my boo-tay in gas and grease!

I'd love to buy my (deep breath....) 1991-95 5'er E34 M50 -- but I speculate at least 8 weeks of more questions while I learn and look.

Merci, Gracias , Danke, Thanks!

Jamie

Nothing is as simple as a 1966 Mustang any more!

Weren't their gas tanks strategically placed behind the rear seat, as to explode in a collision? I understand to change the in-tank fuel pump, simply lower the middle arm rest, unscrew the unit, re-install and close the arm rest.

The good old days. No seat belts, no air bags, no ABS. People just never crashed back then, before we lived in color.

LOL

I think you've just been unfortunate. I've owned many cars, and not one has suffered a pump or sender problem. Failures don't appear to be that common.

As a BTW the tank unit in your Volvo is probably made by Ford. For many years they've been one of the biggest manufacturer of tank units in the world, Supplying units to most european car Co's. AFAIK the list doesn't include BMW or Mercedes, but it does include most of the others, Renault, Citroen, Peugeot, Vauxhall, etc, and of course Fords own cars. Mike.