Fuel Gauge.

[andyglym]

My fuel gauge suddenly only reads up to a quarter full even when full? This came about post my speakers being fitted. I've popped on my code reader and had a few related to the airbag and seat and cleared them and now not showing any codes, what could this be please? Their's power to it as it moved from empty, with the light on, then to empty circa 50 miles with a full tank
Any direction most appreciated

 

[Grumps]

Sender in the tank?

 

[andyglym]

Sender in the tank?

Dunno mate, could be? I believe that's behind the drivers seat? She's washed and tucked up 'till next Friday now so I'll look then. Ta for the info

 

[Synclare]

Easy to get to. The carpet has a line marking the access point behind drivers seat. I have spare units assuming pre/post facelift the same.

 

[andyglym]

Easy to get to. The carpet has a line marking the access point behind drivers seat. I have spare units assuming pre/post facelift the same.

Thanks Adrian, I'll take a look and check and get back to you the weekend after this one coming

 

[Synclare]

You can have one on a 'try before you buy' basis. No point buying one if it doesn't sort it.

 

[andyglym]

You can have one on a 'try before you buy' basis. No point buying one if it doesn't sort it.

I'll drop you a PM nearer the time mate. TVM

 

[mrscalex]

Years ago (crikey nearly 30) I had a brand new XR3i company car that had this issue. It turned out to be the float rubbing against the tank and getting stuck. I'm not sure how possible that is with a Z3 but I'd certainly start with swapping the pump/float assembly.

You can indeed punch out the window in the carpet to access the pump. But I think that's a shame so I pull the rear plastics out to peel the carpet away properly.

 

[andyglym]

Years ago (crikey nearly 30) I had a brand new XR3i company car that had this issue. It turned out to be the float rubbing against the tank and getting stuck. I'm not sure how possible that is with a Z3 but I'd certainly start with swapping the pump/float assembly.

You can indeed punch out the window in the carpet to access the pump. But I think that's a shame so I pull the rear plastics out to peel the carpet away properly.

Mine already has a flap to reveal the sender unit, not sure if by design or not?

 

[mrscalex]

It's pre-marked or even perforated (I think) so it's easy to locate and cut.

But it left the factory intact - well on all the cars I've seen. So this suggests someone has been in there before you which might just be a clue in some way if it was repaired with an iffy second-hand part or not fitted properly etc.

 

[Redline]

As said possibly the fuel sender float has jammed. If you’ve been working close to the wiring around there it’s possible that a connection has become dislodged - possibly the earth out of the sender.
Going to be an electrical problem of some kind. Diagnostics won’t see it. It appears to be sending a valid level reading.

 

[andyglym]

As said possibly the fuel sender float has jammed. If you’ve been working close to the wiring around there it’s possible that a connection has become dislodged - possibly the earth out of the sender.
Going to be an electrical problem of some kind. Diagnostics won’t see it. It appears to be sending a valid level reading.

Thanks Ian. The level reading when full to the brim is only 1/4 full.

 

[hard top]

@Andy McDonnell .... This any help?
https://www.bimmerforums.com/forum/...el-Gauge-Fixes-Stuck-Low-Fuel-amp-Wacky-Gauge

 

[Grumps]

It's pre-marked or even perforated (I think) so it's easy to locate and cut.

But it left the factory intact - well on all the cars I've seen. So this suggests someone has been in there before you which might just be a clue in some way if it was repaired with an iffy second-hand part or not fitted properly etc.

Thanks Ian. The level reading when full to the brim is only 1/4 full.

I reckon it's the sender sticking mate. Had exactly the same on Jues Freelander. It's an easy fix even for us novices

 

[andyglym]

@Andy McDonnell .... This any help?
https://www.bimmerforums.com/forum/...el-Gauge-Fixes-Stuck-Low-Fuel-amp-Wacky-Gauge

Thanks Mike, a potential free fix. I'll un-hook the battery when home next and see if it resets to normal on hook-up. Great find

 

[andyglym]

I reckon it's the sender sticking mate. Had exactly the same on Jues Freelander. It's an easy fix even for us novices

Novice! I'm not that good

 

[Antm72]

It may be a dislodged a connection up under the dashboard on the rear of the clocks..It does sound like an earth problem causing it to miss read.

 

[mrscalex]

The back of the dash has very positive cable fittings. I think the fault is unlikely to be there unless the clip has broken off or it's been previously fiddled with. if you don't know how to engage these clips properly they will come undone. I guess damp may have got in there but I think it would be an usual place.

These things (this is the ZKE module behind the glove box but same thing as instrument cluster)

 

[andyglym]

The back of the dash has very positive cable fittings. I think the fault is unlikely to be there unless the clip has broken off or it's been previously fiddled with. if you don't know how to engage these clips properly they will come undone. I guess damp may have got in there but I think it would be an usual place.

These things (this is the ZKE module behind the glove box but same thing as instrument cluster)

View attachment 92228

It only came about after we'd had the ignition on for an extended period of time when working on the windows and runners. All top advice so far, I'll start with the battery reset first then go from there.

 

[hard top]

Novice! I'm not that good

You are not going to want to read this .....
I had the same problem with my car, seems to happen a lot as the cars get older?
When the gauge showed 1/4 full on mine, it was actually in reserve and after I found that out the hard way, I just learnt to live with it and read 1/4 full as empty....