Fuel gauge anomaly

[Borris]

We have just been abroad for the last ten days. Well actually it was the Isle of Wight but for most of our break it was like being in the Med. Absolutely gorgeous. It was to has been the inner Hebrides until I read that the midge season has just begun.

Anyway we had just got off of the return ferry at Lymington when I glanced at the fuel gauge and was alarmed to find that it read empty with 0 miles left in the tank. We had only just put £20 of Tescos supermarket diesel ordinaire in the tank. This was only a few miles back just to get us to the main land so I knew that the tank wasn't that empty. Margot our Cali, likes only the finest BP Ulitmate diesel juice to keep her in fine fettle and there aren't any BP stations on the I of W. (Using only BP Ulitimate is an on going experiment on my part to try to ward off future DPF and other issues. Whether it's any good remains to be seen).

When we drove onto the ferry we were directed to park on the elevated ramp section above the main car deck. We were positioned near to the front so that when the ramp was lowered prior to disembarkation we ended up parked on the steep sloping ramp.

All that I can think of is that the contents of the tank didn't register as the fuel had gone to the other end of the tank away from the fuel gauge sender unit. When I turned on the ignition it read contents zero. However when on the flat I would have expected the gauge to register something but instead it continued to read zero until after I had stopped and filled up. Spooky.

Is this something to be expected under these circumstances or do I have an issue?

P.s Pretty much all of the major roads and many of the minor ones in the Isle of Wight have recently be resurfaced to a very high standard. Not the usual shoddy fling some black stuff about and don't bother raising the drain covers nonsense. I have been told that this was following an EU grant. The roads had been appalling. Anyway it is now a great place to drive around.

 

[jts46]

Perhaps if you switch off ignition (on the level) then switch on again it may read correctly?

 

[Borris]

I did try that before I filled up but it stayed at zero. Once I had filled up all returned to normal.

 

[Victor]

https://vwcaliforniaclub.com/threads/faulty-fuel-guage.1057/#post-152270

 

[Shadrack]

Hi Borris,
I hope I am not stealing or interrupting your thread but Just reading your thread I picked up on the BP Ultimate comment. I to have been running a few trials on the 'better fuel'. I have just used a tank of ultimate and a tank of the regular. More to see if any improvement in economy.
I felt the economy was not as good on the so called better fuel. Not sure about how it cleansed or improved engine components.
But the cost was 11p per litre more for the ultimate. I don't know how you have found things to date. But I feel buying an additive to maintain if and when needed will be far more economical than the ultimate when it is required.

 

[Borris]

Hi Borris,
I hope I am not stealing or interrupting your thread but Just reading your thread I picked up on the BP Ultimate comment. I to have been running a few trials on the 'better fuel'. I have just used a tank of ultimate and a tank of the regular. More to see if any improvement in economy.
I felt the economy was not as good on the so called better fuel. Not sure about how it cleansed or improved engine components.
But the cost was 11p per litre more for the ultimate. I don't know how you have found things to date. But I feel buying an additive to maintain if and when needed will be far more economical than the ultimate when it is required.

Hello Shadrack,
I haven't carried out any checks on the economics of this fuel although I do keep records so I can work out an accurate mpg figure over the 11500 miles to date. However, since I haven't been using standard diesel I am unable to say at this stage if BP Ulitimate provides any extra mpg.
My reason for using it is because of BP's claim that it maintains a much cleaner engine. It is more expensive to buy but if it does keep the engine cleaner and ward off big bills for repairs then it might just be better value than ordinary supermarket diesel long term. If it gives better mpg as well then that's a bonus.

The trouble is how can you tell if their claims are true apart from either waiting to see if the vehicle goes on for zillions of miles without issue or by taking the whole engine to pieces to check it's internals. Obviously I am not going to do that but BP must have run extensive tests followed by complete strip down for inspection in order to make this claim.
I haven't tried additives as that would corrupt my experiment. Also would their use effect the warrantee?

It comes down to this. Either it works or I will have wasted some cash.

 

[Shadrack]

Hi Borris,
I had looked at the better economy side to see if the extra cost of ultimate would be balanced out by the better mpg achieved.

As for looking after the engine, I had not thought about that. I do understand and agree with your point of view. I am certainly not a fan of supermarket fuel. A local supermarket near to me is renowned for having water in the tanks during the flood season and a few local repair garages benefit from this. I too in a previous motor had two fuel pumps replaced until I caught on.
So I tend to always use branded fuels now.
I don't know what goes on inside the modern engines and have reached an age were I leave it to my wallet in adverse situations. But like most I guess I would rather not have to go there too often.
I have done a rough calculation on your miles V extra cost of ultimate and I think it's less than a £100 overall. So I do agree that in the grand scheme of things that's not a bad price to pay for piece of mind.
I have not yet looked into the additives and again to their claims. Also the possible warranty issue you raised. Maybe a rethink on my behalf is needed and further research before I go down that road.

 

[Borris]

Hi Borris,
I had looked at the better economy side to see if the extra cost of ultimate would be balanced out by the better mpg achieved.

As for looking after the engine, I had not thought about that. I do understand and agree with your point of view. I am certainly not a fan of supermarket fuel. A local supermarket near to me is renowned for having water in the tanks during the flood season and a few local repair garages benefit from this. I too in a previous motor had two fuel pumps replaced until I caught on.
So I tend to always use branded fuels now.
I don't know what goes on inside the modern engines and have reached an age were I leave it to my wallet in adverse situations. But like most I guess I would rather not have to go there too often.
I have done a rough calculation on your miles V extra cost of ultimate and I think it's less than a £100 overall. So I do agree that in the grand scheme of things that's not a bad price to pay for piece of mind.
I have not yet looked into the additives and again to their claims. Also the possible warranty issue you raised. Maybe a rethink on my behalf is needed and further research before I go down that road.

That's interesting that the difference is so little. I could sit down and work out what the mpg has been to date on our SE. I could then compare my figures with those of other forum members. However, as there are so many variables such as, model, age, service regime, tyre type, tyre pressures, driving style, type of regular road use etc etc, IMO it wouldn't produce any meaningful results. The only real test would be to accurately work out my average mpg to date and then do the next 11500 miles using supermarket juice and then work out the comparison. Even then, the engine would be looser having done more miles so even those figures would be a little skewed. However, that would give me a comparison of sorts but would stop my current experiment dead.

Whilst I am interested in my vehicles mpg, I no longer spend that much time watching the mpg readout on the intrument cluster. There was a time when every journey became a contest to see how high I could get the average mpg up to but driving like that requires a lot of extra concentration over a long period and can be exhausting. Most of the time I just can't be bothered.

I suppose that I should also mention that Mrs B and I also own a T6 Beach 150 manual with 8500 miles since we purchased it new and a Skoda Superb estate 170 dsg diesel which we purchased at three years old with 18500 miles, currently 22000 miles. We are also running these two vehilcles on BP Ultimate. So the experiment is a bit more extensive than I originally indicated.

From memory the average mpg of these vehicles on a fairly long run at 60-70mph is:
SE 180 dsg 4motion - 35 to 37 ish mpg
Beach 150 manual - around 47 ish mpg
Skoda 170 dsg - around 52 to 55 ish mpg
However if I concentrate of achieving high mpg figures they have all been much higher. Note: these figures are from the instrument read out and not worked out from my records or brim to brim tests so should be taken with a pinch........

I do also carry out the ritual thrashing of all three vehicles to clear out the dpf. That is to drop gears until your driving continuously at 3000 to 3500 revs for 20 - 30 minutes every time we are on a long run. Best done on the motorway. Our Beach is mainly used as a day van and does most of it's mileage on short local low speed trips, school runs, shopping etc. Every so often the dpf regeneration cycle will start up when I switch off. It makes more noise than the engine! I will then give it a damn good thrashing and it doesn't do it again for some time afterwards. The other vehicles don't have this feature so the first indication I would get of a potential problem would probably be an engine management light coming on. So far so good.

 

[Shadrack]

Hi Borris,
A very informative and interesting post. As my ocean is relatively new with only a couple of thousand or so on the clock. I think I am still at the stage of watching the mpg readout. (Around 41 mpg with little motorway use)
I am impressed with your beach mpg figures. (I am not familiar with the other motors) As you have said already there are so many variables but I am thinking the 'ultimate' by BP has contributed?

I have just re read the post and realise I may have gone well off the topic. My apologies. I do hope the fuel gauge is ok and all is good.
Thank you for your thoughts and helpful information.

 

[WelshGas]

We have just been abroad for the last ten days. Well actually it was the Isle of Wight but for most of our break it was like being in the Med. Absolutely gorgeous. It was to has been the inner Hebrides until I read that the midge season has just begun.

Anyway we had just got off of the return ferry at Lymington when I glanced at the fuel gauge and was alarmed to find that it read empty with 0 miles left in the tank. We had only just put £20 of Tescos supermarket diesel ordinaire in the tank. This was only a few miles back just to get us to the main land so I knew that the tank wasn't that empty. Margot our Cali, likes only the finest BP Ulitmate diesel juice to keep her in fine fettle and there aren't any BP stations on the I of W. (Using only BP Ulitimate is an on going experiment on my part to try to ward off future DPF and other issues. Whether it's any good remains to be seen).

When we drove onto the ferry we were directed to park on the elevated ramp section above the main car deck. We were positioned near to the front so that when the ramp was lowered prior to disembarkation we ended up parked on the steep sloping ramp.

All that I can think of is that the contents of the tank didn't register as the fuel had gone to the other end of the tank away from the fuel gauge sender unit. When I turned on the ignition it read contents zero. However when on the flat I would have expected the gauge to register something but instead it continued to read zero until after I had stopped and filled up. Spooky.

Is this something to be expected under these circumstances or do I have an issue?

P.s Pretty much all of the major roads and many of the minor ones in the Isle of Wight have recently be resurfaced to a very high standard. Not the usual shoddy fling some black stuff about and don't bother raising the drain covers nonsense. I have been told that this was following an EU grant. The roads had been appalling. Anyway it is now a great place to drive around.

Did you leave the key in the Ignition when refuelling?

 

[Borris]

Did you leave the key in the Ignition when refuelling?

No I don't think so. Whilst I cannot remember for sure, that would be most unlikely. I never leave the keys in the ignition at fuel stations in case of theft but also because I have always been worried about the vehicle locking itself. The locking system has always been a bit of a mystery despite several attempts to read up on it. On this occasion I filled up whilst my wife went in to pay.

Before filling up I turned off the ignition, waited a few seconds and then tried switching on again but the gauge still read empty. This was at the fuel station before I filled up.

 

[briwy]

I was talking to a guy we met on a MotoGP campsite a while ago who turned out to have been the chief exec of Shell UK.
I know it could be expected that he would be biased but he says that Shell (and presumably other large oil companies) cary out back to test on engines with different brands and grades of fuel. Apparently they buy a batch of engines (all the same), and run them on the different fuels until they die .
He says that there is no doubt that long term the more expensive options give longer engine life, but not necessarily much more mpg if that it what you are looking for to justify the extra cost.
My own brief test with super fuels didn't seem to give better mpg so now we stick to the main brands ordinary fuel. Definitely no supermarket stuff.

 

[WelshGas]

No I don't think so. Whilst I cannot remember for sure, that would be most unlikely. I never leave the keys in the ignition at fuel stations in case of theft but also because I have always been worried about the vehicle locking itself. The locking system has always been a bit of a mystery despite several attempts to read up on it. On this occasion I filled up whilst my wife went in to pay.

Before filling up I turned off the ignition, waited a few seconds and then tried switching on again but the gauge still read empty. This was at the fuel station before I filled up.

The reason I asked is that on the T5.1, if the key is left in the ignition or close to the ignition housing while refuelling then the fuel gauge shows a
lower than expected reading which can take some time, 24/48hrs to return to the correct level.

 

[Borris]

The reason I asked is that on the T5.1, if the key is left in the ignition or close to the ignition housing while refuelling then the fuel gauge shows a
lower than expected reading which can take some time, 24/48hrs to return to the correct level.

That's very interesting and something else to guard against.

In my case the fuel guage read zero immediately before refueling even though the tank wasn't empty but registered normally once more fuel had been added. I feel this issue may have been caused by the vehicle being pitched nose down on the ferry ramp before I turned on the ignition to drive off. Perhaps once the vehicle had registered no fuel on start up, it needs either the keys out of the ignition or more fuel or both to reset the system. Before refueling at the pump I had turned off the ignition and then turned it on again but it had still indicated empty. Perhaps that's something to do with what you have mentioned above.

In days of old the float and sender unit in the tank would give a resonably accurate reading all of the time but with these modern vehicles the electronics are so complicated that it's sometime difficult to know what's happening.
Thanks for the information.

 

[Borris]

I was talking to a guy we met on a MotoGP campsite a while ago who turned out to have been the chief exec of Shell UK.
I know it could be expected that he would be biased but he says that Shell (and presumably other large oil companies) cary out back to test on engines with different brands and grades of fuel. Apparently they buy a batch of engines (all the same), and run them on the different fuels until they die .
He says that there is no doubt that long term the more expensive options give longer engine life, but not necessarily much more mpg if that it what you are looking for to justify the extra cost.
My own brief test with super fuels didn't seem to give better mpg so now we stick to the main brands ordinary fuel. Definitely no supermarket stuff.

Hello Brian,
Your conversation with the Shell UK CEO has confirmed what I had suspected. So if he is correct then the roof will have corroded away long before the engine goes pop. We shall see.
Going off thread for a moment I am writing this whilst watching the light weight Isle of Man tt on the telly box. IMO the best sporting event of the year by a country mile. I have never been able to work out if they are real men or just stark raving nutters.

 

[briwy]

What ever they are Paul it's sad that so many of them die. Most dangerous form of motorsport. Bad day yesterday.

 

[Borris]

What ever they are Paul it's sad that so many of them die. Most dangerous form of motorsport. Bad day yesterday.

Yes I completely agree. It is aways tragic when anyone dies and sadly that is and has always been, an all too frequent occurance in the tt. However they all choose to compete in this unique event and I am certain that each and every competitor would want the tt to continue, unchanged, into the future.
My own brother was killed in 1998 after high siding his Fireblade at a track in Kent. He had already had a couple of bad accidents but motorcyles were like a drug to him so he didn't for once think that it might be a good idea to quit riding. He went to the tt before his death and absolutely loved it.
Yet despite this personal tragedy I still find the tt compelling viewing and I am not a biker.
Now we really have strayed off thread.