2002 Carbureted Fuel Gauge Sending Unit HELP

[Brakey]

I am on the lookout for a new fuel gauge sending unit. I have scoured the internet and contacted many companies including one in Germany.

BMW has stopped production and the supply has dried up with no ETA on them.

Just sold off one 2002 with a bad sending unit and I have another 1973 that I would like to have a replacement for.

I pulled the sending unit from the 02 I sold and found that the resistance wires running from the float to the piece that attaches to the tank are extremely light, fragile and IMHO are of poor design and destined to fail.

Both of these do not have the low fuel warning light and yes I do know how to troubleshoot if its the gauge, wiring or sending unit.

 

Has anyone substituted a later or similar  model part, modified a US production sender to act as a replacement.

Please advise and thanks in advance

[Mike Self]

So what's happening with yours?  Does the gauge read at all, or is it always on full--or empty?

The problem can be in the gauge, but you're correct in that it is more likely the problem is in the sender.  

 

If the resistance wires are intact and the float slides freely up and down them, sometimes a simple cleaning of the wires and contacts on the float with either carburetor cleaner or lacquer thinner will get things working again.  Use a q-tip (or two) as the wires are very fragile.  Gas can build up a coating on the wires and it doesn't take much to insulate 'em so the resistance doesn't register (the gas gauge is basically an ohmeter).  

 

The wires can also be replaced with wire of a similar resistance.  I've seen 6 ohms/inch as the proper resistance.

 

mike

[andyleonard]

There are several different $50-$70 generic tube-style (like 2002, no swing arm float) senders available to enable racing fuel cells to talk to vintage instruments in vintage race cars. You get your choice of depth and resistance. Using the old sender for depth and with gauge resistance requirements in hand you should be able to find one. If the mounting is an issue and the top of the new sender is small enough you might use the dead gauge mounting plate and set the new sender into that. If it's bigger it'll mount right on the tank.

 

See Summit or Jegs for Classic Instruments sender or equivalent.

[jrhone]

Last time I needed one Mesa Performance had it in stock. Call them. They have so much stock of sometimes NLA parts. They are in Costa Mesa, California. 

[Brakey]

Thanks all for the input. I will check out Mesa Performance and Summit for generic gauges.

I have checked with multiple suppliers that still list the unit as available but when called have no stock and when they investigate find that BMW has stopped production as of spring of 07 with no ETA or start of production date.

As stated in the original post, I do know how to troubleshoot if its the gauge or the sender. I have 2 that have bad sending units.

There are very simple tests to determine which is at fault.

IMHO these sending unit are very flimsy. The resistance wire is extremely thin.  I'm surprised the German Engineers at BMW let this slip through back then. 

[jimk]

42 minutes ago, Brakey said:

I'm surprised the German Engineers at BMW let this slip through back then. 

Isn't the float supported by the center rod, not the resistance wires.  So I don't see where the small diameter resistance wire can be called flimsy because the sliding contacts do not load the wires. 

Edited November 30, 2017 by jimk

[Brakey]

Sensitive comment, are you a German Engineer?

 

It's not the fact that the rides on the center rod (its not supported by it). The fact is that these wires are so small they resemble the lightest I have ever seen.

When you remove the sending unit and pull the can off and the wires are going in every direction and not hooked to anything I think there is a problem.

 

German engineers are not infallible they just think they are always right and its their way or the highway. I worked as an engineer for the Germans for a number of years and it has been true for every design and development action we tried to make.

 

I do like my E10 2002 and accept some of the shortcomings. They (mine) are 45 years old, technology has moved on.

 

 

[jimk]

35 minutes ago, Brakey said:

Sensitive comment, are you a German Engineer?

 

It's not the fact that the rides on the center rod (its not supported by it). The fact is that these wires are so small they resemble the lightest I have ever seen.

When you remove the sending unit and pull the can off and the wires are going in every direction and not hooked to anything I think there is a problem.

No I am an American engineer, 38 years in the business and a 2002 owner for 45 years.

I just removed the can from a sending unit and the wires do not "go everywhere".  The wires are strung tight and tensioned by the two leaf spring type holders at the top where the wires are soldered to.

At the bottom, they are retained by a crossmember type holder near the end of the rod. The holder is locked to the rod by a 5.5mm nut.  Maybe yours is just missing parts.  Previous owners/technicians may have had it apart and didn't get things put together as they should be. 

Edited November 30, 2017 by jimk

[Brakey]

Despite the conjecture, the fact remains that there are none available and BMW stopped production. I'm looking for a replacement or substitution.

 

I'm amazed the aftermarket parts supply for the 02's are limited.

 

I can buy almost any part new for my Triumphs and MG's but not so for this model BMW.

[02Les]

Maybe this pic will help you decide if you're missing anything.

It's the one in my Touring & probably the original (I've owned the car 31 years) and is working just fine.

 

This 2nd pic shows the two parts at the bottom of the tube/can.

[jrhone]

Damn Brakey lighten up. 4 posts here and in your opinion BMW engineering is shit and the aftermarket parts supply sucks. You also picked a fight with a regular who was trying to help. Google is your friend. I found 4 places that have them in stock in minutes. Maybe try searching by part number.  These are 40-50 year old cars. Aftermarket isn’t there because there is no money in making them. I’m sure there are PLENTY of unobtainable parts for triumphs and mg’s. I can stroll down to my local bmw dealer and order 90% of the parts that came on these cars. I’m sure my local MG or Triumph dealer could...oh. There is a problem.  No MGs or Triumph dealers anymore.