Volvo v70 fuel gauge problem - Page 2

rogereld · Jan 30th, 2012, 21:55

Just thought I would report back with an update.

I made the first post in August 2010. Still remember the frustration of having wife and 3 children getting tired and hungry as we were on our way down the A303 for summer holiday.

I don't know if it was the stress of having a full car that affected something, but after that AA callout in 2010 I have not touched the fuel tank since. The problem has never re-appeared. The AA engineer slightly loosened the top of the float/sender unit (under the rear seats) and he may have turned it slightly. That may have solved the problem.

I have never spent any time or money on it and the problem has never reappeared.

micken · Jan 30th, 2012, 22:51

I'm wondering if the motorway breakdown that I had before Christmas is linked to this fuel supply issue. I reported it here http://www.volvoforums.org.uk/showthread.php?t=141599

A day or so after the recovery I was coming out of a multi storey car park and heard a metallic 'twang', like you would get from a metal bin. I thought that someone had thrown something from the car park that had bounced off the roof of the car, but when I stopped and looked there was absolutely no evidence of this. I wondered at the time whether there could have been an air lock or something else that had caused the wall of the fuel tank to spring or get knocked and therefore making the noise. I've had no signs of fuelling problems or poor running since and this has included further motorway miles.

Strange.

LJD · Mar 29th, 2012, 11:00

This happened to me last night
I had only just bought the car!

so all this is good news to assist my mate who is a mechanic

will post up what he finds !

Luke

Joe Harding · Oct 30th, 2012, 17:29

Anything to report? I'm curious to see if anyone else has our problem with wiring between the float switches and the DIM.

coughlanc · Oct 30th, 2012, 17:38

I've never had this exact thing happen but since owning my 2001 V70 the fuel gauge has always been inaccurate. Once the guage reads just under 1/4 (red light not on at this point) and range says 70 miles or less engine won't start if left over night.

rogereld · Oct 30th, 2012, 20:26

After a breakdown and AA recovery last weekend I should probably update this thread with a link to my recent thread titled: "Engine power failed at 70mph on motorway"
http://www.volvoforums.org.uk/showthread.php?t=165518

As a quick summary:
After more than 2 years with no problem, we broke down on the M5 last weekend, and after calling the AA we were recovered by a contracted recovery company to the nearest service station where the mechanic looked for a fault to repair. He found no fault codes, and then removed and tested a spark plug and concluded there was no spark. At that point he decided it was not repairable and needed trailer recovery back home, a journey of 140+ miles and 2.5 hours.

I did not really think fuel was the problem as the gauge had been behaving normally, and had gone from 3/4+ to 1/2 during our 2 hours of motorway driving which is what I would normally expect to see for that mileage.

I did mention we had broken down a couple of years before and that the AA mechanic took more than 1 hour to discover we were out of fuel on that occasion. I suggested trying a bit of fuel just in case, as the filling station was only a few yards away, but he said if there was no spark it was not worth doing and left us to be collected by an AA trailer driver who arrived later.

Car was returned home and after checking all the electrical fuses and recharging and testing the battery I put 5 litres of petrol in the tank and started the engine first turn of the key. I then managed to get an additional 68 litres in the tank so my conclusion is breakdown was due to empty fuel tank with faulty gauge indicating more than half full at the time of breakdown.

oldgreybloke · Nov 9th, 2012, 18:19

Quote:

Originally Posted by coughlanc

I've never had this exact thing happen but since owning my 2001 V70 the fuel gauge has always been inaccurate. Once the guage reads just under 1/4 (red light not on at this point) and range says 70 miles or less engine won't start if left over night.

I have found, with my 2001 V70, that while I can drive the car to the point where it is running on fumes, if I stop the engine and leave it, say overnight, when there is anything less than 25 miles on the "miles left" reading, it will not start.

rogereld · Nov 9th, 2012, 22:55

If the fuel gauge was consistently wrong I would at least know what to expect and compensate accordingly. With a correctly working gauge for more than 2 years I have grown to rely on it. Roadside rescue mechanics took almost an hour to find the fault two years ago, and did not find it at all on our recent motorway breakdown so they probably also assume it is correct.

I would like to know how the gauge actually works. I think there are two "senders" under the rear seats. Why are there two, and how do they combine to send a signal to the gauge. Does one sender measure from full to 1/2 tank and the other sender measure 1/2 to empty. My gauge got stuck showing 1/2 tank of fuel when it was in fact empty, and if different senders cover different parts of the scale that could give me some clue where to start looking for a fault.

Clan · Nov 10th, 2012, 09:03

Ther are effectivly 2 tanks each with a sender the senders are wired in series .
the fault is most likely the left float fouling the pipes and wires in the tank , slacken the securing ring and turn the sender a small amount anticlockwise and try that . There is a pointer on top of the sender and two marks towards the rear on the tank , the pointer should be between the two marks but alter it to align with the most anti clockwise mark ... try that ,

rogereld · Nov 10th, 2012, 09:36

Thank you Clan. I will have a look at the nearside sender.

The AA mechanic got as far as looking at this sender 2 1/2 years ago when he diagnosed we had run out of fuel but I was never able to tell if he had moved it (clockwise or anticlockwise) as I did not know where the marks were aligned before his intervention. After more than 2 years with no problems I assumed it was fixed, but recent experience suggests otherwise.

You made a very helpful comment earlier in this thread, back in 2010, where you suggested turning the sender clockwise. This time you suggest moving it anticlockwise. Does this mean the position of the float is easily obstructed in either direction. Is it a lot of extra work to take the sender out so I can look in the tank and see what is actually there to cause obstruction? I guess I should disconnect the battery to avoid sparks around the open tank if I do this.

It is possibly more information than I need, but why do you think it is most probably the left sender and not the other one?

Oct 30th, 2012, 17:29	#14
Joe Harding Premier Member Last Online: Yesterday 20:53 Join Date: Oct 2010 Location: Bristol	Anything to report? I'm curious to see if anyone else has our problem with wiring between the float switches and the DIM. __________________ "The more people I meet the more I like my God."

Nov 10th, 2012, 09:03	#19
Clan Experienced Member Last Online: Today 00:13 Join Date: Jun 2007 Location: L/H side	Ther are effectivly 2 tanks each with a sender the senders are wired in series . the fault is most likely the left float fouling the pipes and wires in the tank , slacken the securing ring and turn the sender a small amount anticlockwise and try that . There is a pointer on top of the sender and two marks towards the rear on the tank , the pointer should be between the two marks but alter it to align with the most anti clockwise mark ... try that , __________________ My comments are only based on my opinions and vast experience .

Jan 30th, 2012, 21:55	#11
rogereld Senior Member Last Online: May 31st, 2024 19:14 Join Date: May 2009 Location: Southampton	Just thought I would report back with an update. I made the first post in August 2010. Still remember the frustration of having wife and 3 children getting tired and hungry as we were on our way down the A303 for summer holiday. I don't know if it was the stress of having a full car that affected something, but after that AA callout in 2010 I have not touched the fuel tank since. The problem has never re-appeared. The AA engineer slightly loosened the top of the float/sender unit (under the rear seats) and he may have turned it slightly. That may have solved the problem. I have never spent any time or money on it and the problem has never reappeared.

Jan 30th, 2012, 22:51	#12
micken Senior Member Last Online: Nov 7th, 2023 16:55 Join Date: Jan 2007 Location: Leeds	I'm wondering if the motorway breakdown that I had before Christmas is linked to this fuel supply issue. I reported it here http://www.volvoforums.org.uk/showthread.php?t=141599 A day or so after the recovery I was coming out of a multi storey car park and heard a metallic 'twang', like you would get from a metal bin. I thought that someone had thrown something from the car park that had bounced off the roof of the car, but when I stopped and looked there was absolutely no evidence of this. I wondered at the time whether there could have been an air lock or something else that had caused the wall of the fuel tank to spring or get knocked and therefore making the noise. I've had no signs of fuelling problems or poor running since and this has included further motorway miles. Strange.

Mar 29th, 2012, 11:00	#13
LJD I've Been Banned Last Online: Oct 22nd, 2021 18:48 Join Date: Mar 2012 Location: london	This happened to me last night I had only just bought the car! so all this is good news to assist my mate who is a mechanic will post up what he finds ! Luke

Oct 30th, 2012, 17:38	#15
coughlanc Senior Member Last Online: Jun 2nd, 2019 22:26 Join Date: Jul 2011 Location: Sheerness, Kent	I've never had this exact thing happen but since owning my 2001 V70 the fuel gauge has always been inaccurate. Once the guage reads just under 1/4 (red light not on at this point) and range says 70 miles or less engine won't start if left over night.

Oct 30th, 2012, 20:26	#16
rogereld Senior Member Last Online: May 31st, 2024 19:14 Join Date: May 2009 Location: Southampton	After a breakdown and AA recovery last weekend I should probably update this thread with a link to my recent thread titled: "Engine power failed at 70mph on motorway" http://www.volvoforums.org.uk/showthread.php?t=165518 As a quick summary: After more than 2 years with no problem, we broke down on the M5 last weekend, and after calling the AA we were recovered by a contracted recovery company to the nearest service station where the mechanic looked for a fault to repair. He found no fault codes, and then removed and tested a spark plug and concluded there was no spark. At that point he decided it was not repairable and needed trailer recovery back home, a journey of 140+ miles and 2.5 hours. I did not really think fuel was the problem as the gauge had been behaving normally, and had gone from 3/4+ to 1/2 during our 2 hours of motorway driving which is what I would normally expect to see for that mileage. I did mention we had broken down a couple of years before and that the AA mechanic took more than 1 hour to discover we were out of fuel on that occasion. I suggested trying a bit of fuel just in case, as the filling station was only a few yards away, but he said if there was no spark it was not worth doing and left us to be collected by an AA trailer driver who arrived later. Car was returned home and after checking all the electrical fuses and recharging and testing the battery I put 5 litres of petrol in the tank and started the engine first turn of the key. I then managed to get an additional 68 litres in the tank so my conclusion is breakdown was due to empty fuel tank with faulty gauge indicating more than half full at the time of breakdown.

Nov 9th, 2012, 22:55	#18
rogereld Senior Member Last Online: May 31st, 2024 19:14 Join Date: May 2009 Location: Southampton	If the fuel gauge was consistently wrong I would at least know what to expect and compensate accordingly. With a correctly working gauge for more than 2 years I have grown to rely on it. Roadside rescue mechanics took almost an hour to find the fault two years ago, and did not find it at all on our recent motorway breakdown so they probably also assume it is correct. I would like to know how the gauge actually works. I think there are two "senders" under the rear seats. Why are there two, and how do they combine to send a signal to the gauge. Does one sender measure from full to 1/2 tank and the other sender measure 1/2 to empty. My gauge got stuck showing 1/2 tank of fuel when it was in fact empty, and if different senders cover different parts of the scale that could give me some clue where to start looking for a fault.

Nov 10th, 2012, 09:36	#20
rogereld Senior Member Last Online: May 31st, 2024 19:14 Join Date: May 2009 Location: Southampton	Thank you Clan. I will have a look at the nearside sender. The AA mechanic got as far as looking at this sender 2 1/2 years ago when he diagnosed we had run out of fuel but I was never able to tell if he had moved it (clockwise or anticlockwise) as I did not know where the marks were aligned before his intervention. After more than 2 years with no problems I assumed it was fixed, but recent experience suggests otherwise. You made a very helpful comment earlier in this thread, back in 2010, where you suggested turning the sender clockwise. This time you suggest moving it anticlockwise. Does this mean the position of the float is easily obstructed in either direction. Is it a lot of extra work to take the sender out so I can look in the tank and see what is actually there to cause obstruction? I guess I should disconnect the battery to avoid sparks around the open tank if I do this. It is possibly more information than I need, but why do you think it is most probably the left sender and not the other one?

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