Reserve tank woes

[Nawest]

After owning Toyotas for the last twenty years, I took the plunge and bought a 55 plate CLK 280. I love the car, but in the four weeks I've owned it I've already had a couple of 'faults'. First a cam sensor needed replacing and today, with fuel in the tank and a range of 30 miles showing, it ran out of petrol, on a busy roundabout, in a traffic jam!

Now, I know I was running on reserve fuel, but I thought seeing as the petrol gauge still had 2 bars and the computer said I could drive another 30 miles, that I'd quite easily be able to travel another couple of miles to fill up. The RAC guy that towed me to the nearest petrol station said he was also slightly surprised that the car said different to what the situation actually was.

If I remember correctly, the reverse tank holds eight litres, and since the notification came up on the dash, I can't have done more than twenty miles at regular speed limits and without excessive accelerating or braking. So, is this the norm for CLKs or is there something amiss with my car?

 

[renault12ts]

Like any car...it's a learning curve.

You have now learnt the point at which you WILL run out of fuel as opposed to MIGHT run out of fuel.

 

[Nawest]

Like any car...it's a learning curve.

You have now learnt the point at which you WILL run out of fuel as opposed to MIGHT run out of fuel.

Thanks for that

So, am I to understand that my wife's 53 Toyota Avensis can accurately predict the cars range when my (originally) twice as expensive, and younger Merc can't?

I realise that all cars are different but are you saying that there's not a fault somewhere when eight litres of fuel only takes me twenty miles?

 

[renault12ts]

Thanks for that

So, am I to understand that my wife's 53 Toyota Avensis can accurately predict the cars range when my (originally) twice as expensive, and younger Merc can't?

I realise that all cars are different but are you saying that there's not a fault somewhere when eight litres of fuel only takes me twenty miles?

Try to fill up when your the fuel light goes on. That way you can gauge how much fuel is actually left when the reserve is being used.

 

[Deleted member 37751]

I've never had this problem with any of the Mercedes I've owned?

I'd definitely be looking into this if it was my car.

 

[SavMan]

You are brave, driving "approx" 20 miles in a V6 convertible Merc, during that time you will probably have used at least half the reserve tank so in effect you will have just 4 litres sloshing around in the tank.

Sounds like you have not had the best of starts to you ownership I am sure things will get better particularly as the warmer weather starts and the longer days mean some enjoyable trips, you'll look back and laugh at the bad start you two have had (unless of course you are so busy enjoying the drive you don't realise your fuel light has been on for the last 20 miles)

 

[Nawest]

You are brave, driving "approx" 20 miles in a V6 convertible Merc, during that time you will probably have used at least half the reserve tank so in effect you will have just 4 litres sloshing around in the tank.

But that's the point savman, according to the car, driving twenty miles used ALL EIGHT litres in the reserve, which works out at approx 11.5 miles per gallon!

I'll not know for sure until I fill the tank and record the mileage but that's a little worse economy than I was expecting, even from a v6!

 

[jefrs]

Twenty miles in a traffic jam will use a lot more fuel than cruising.

I get 22 to 30 mpg out of the E320, and I haven't got a light foot.
I also reset the trip odo when I put a tank full in, I've got a good idea how many miles that will do, and no computer telling me - the low fuel warning lamp means fill up, now!

 

[Dieselman]

Probably the sender needs calibrating properly.

 

[Oli]

I had my E55 showing no lines on the fuel gauge display and 0 miles on the computer a couple of times and it never ran out befre I got to a petrol station, probably an issue with the sender.

 

[amg fan]

Could be the sender sticking I had a w203 that would always be qtr of a tank out so maybe it's always reading it has more onboard that it actually has. You might notice the fuel level staying at a set level for ages and then drop off when closer up to half tank, at least this may point you in the right direction.

 

[Shude]

I had my E55 showing no lines on the fuel gauge display and 0 miles on the computer a couple of times and it never ran out befre I got to a petrol station, probably an issue with the sender.

I have driven down to 0 gallons / 0 miles remaining a few times (with a petrol station in sight!) - it tends to be highly accurate. I know I can reliably do at least 30 miles when the light comes on.

 

[Nawest]

Twenty miles in a traffic jam will use a lot more fuel than cruising.

I'd only been in the traffic jam for about 100 metres, the rest of the 20 miles was on rural roads.

Thanks for everyone's comments/suggestions, I'm going to ask about having the sender unit checked.

 

[Mercator]

With my S210 320cdi I had it conk out when the computer was showing 0.8 gallons while driving up a slight incline. Naturally was very wary about going under a gallon after that.

I wonder why on the S211 display it only shows estimated miles remaining rather than quantity remaining, which I think is preferable. Looking at bars on a dial seems retrograde.

 

[Aswall]

I have never owned a car that wouldn't do at least 30 miles after reading zero miles left.
Saying that, it's impossible to know on my current car as it comes,up with low fuel warning at 70 miles left! Then at 50 miles left it stops displaying a figure

 

[jefrs]

I'd only been in the traffic jam for about 100 metres, the rest of the 20 miles was on rural roads.

Thanks for everyone's comments/suggestions, I'm going to ask about having the sender unit checked.

Sure, have the sender checked. It is after all a glorified lavatory ballcock, you may as well replace it in the process.

If you want accurate then it would have to be calibrated (£££) and then it would need re-calibrating every year. Why bother when it is "for indication only".

I think the sender comes out somewhere in the boot, which is pretty easy to get at. Sometimes the float splits and you get a false reading, other times they pack up completely. I have replaced one, once, not MB, because a dysfunctional fuel gauge is a pita.

 

[gIzzE]

When I got my W210 E320 petrol the guage wouldn't drop below 1/4 tank, I noticed it fall from about a 1/3 to 1/4 in about 80 miles but the next 50 odd miles it didn't move.
I pulled into a filling station and got 70 odd litres in it, so knew something was up.

After reading loads of posts on here I bought some cleaner/additive from Halfords. Being a skeptical kind of chap I was expecting a big bill but thought I would try it.
I put a double dose into half a tank and sure enough the gauge dropped a bit lower, shoved a load more in and the gauge worked as it should.

Nice to get a £5 fix sometimes!

 

[Dichtung]

I ignore `range left`.

The 180K tells me it has 50 miles in the tank; I drive up a mile drag, and then it says 14 miles or so.

If I then drive down a mile drag; it tells me I have 80 miles left.

And so on.

 

[artyman]

Reminds me years ago I backed over a log in the Sailing Club car park, quick look couldn't see any damage, a week or so later though I was getting good consumption then ran out with the guage showing 1/3 full, the sender was resting on a dent in the tank!!!

 

[Rory]

If I remember correctly, the reverse tank holds eight litres,

As far as I know, there isn't a reserve tank, or even reserve fuel. There's just a tank, and fuel.

It's not like the old days of Triumph 2000's where you pulled a knob to use fuel from the reserve tank. The expressions are all virtual these days.