Very poor mpg at 21.5 mpg

[chrisdc]

Originally Posted by chrisdc
These items all sound expensive.... if any of the above were faulty or on their way out, wouldn't the OBC know about this? (logged error code)

Not necessarily, it is even possible to get codes but not get the management light as well.

Good to know.

Ok, sticking callipers won't generate a code but this type of problem usually occurs on older cars that have not been serviced properly (regular brake fluid changes). Correct?

You can get almost brand new cars that develop sticking callipers, there is instances of people on here with nearly new cars and even less than 1yr old that have had to have replacements.

Will take your word for this one. Never heard of it happening to anyone I know and never read of it happening to such new vehicles in any of the motoring / technical journals I've looked at over the years. Perhaps its more of a problem in colder climates? Would the tolerances be more critical at low temperatures? The callipers would contract of course but so would the pistons.

Tyres are Dunlop 6060 series. I'm not a Dunlop fan, preferring Michelin myself, but they had just been fitted a few days before I got the car - so couldn't refuse them. Have inflated as per owners manual.

You may want increase the pressure slightly by about 3 or 4 PSI above standard or onto the pressure settings if the car was fully laden - you should find this will increase MPG slightly. This is
also known as ECO settings.

Good idea. Looking at the car level and unladen the front tyres look flatter than the rear. I suppose its to be expected because of the weight of the engine but why not compensate with a little extra pressure? I'll give it a go and keep a close eye on tyre wear.

I had to strip and clean the EGR valve on my Renault van - lots of black smoke, but it doesn't have a DPF so I was able to see the smoke. Would you know if cleaning of EGR is part of standard Volvo service procedure?

Cleaning of the EGR is not a standard Volvo Service procedure. Volvo would be more interested in just replacing an EGR. It is a very simple job and there is guides on here to follow so definitely one you can do yourself if required.

Thanks, I'll read the guides.

I'm worried that as my car is so close to the end of its Maintenance
Plan, Volvo might choose to "ignore" any potentially expensive problems (especially if they are not obvious failures) in an attempt to buy some time and save themselves some money.

Unfortunately if there is nothing detected and also no codes after a check then as you say Volvo are not going to be interested in any in depth diagnostics to find your MPG loss, especially if it is going to cost them. Unfortunately you are going to have to do the leg work and then if you find anything wrong then you can get Volvo to sort it whilst you are still under warranty.

Noted.

I feel a bit bad saying this of them - they've had to do a transmission repair recently (just before I bought the car) and they're about to replace a faulty deadlock on a rear door so my experience so far has only been good..... still reading the forums, lots of people have not been so lucky. (It took more than a month to get the transmission fault authorised and repaired by the way) The car was "in-between owners" at the time but still.... its a long time to be without a car if its your only transport.

All I can say on this one is; do they not supply a courtesy car whilst yours is in for a repair? The other thing is, as long as you have taken the car to the dealer and ANY fault has been identified and 'Logged on Volvo System' along with all the information required to prove at that point in time it is still under warranty (as you are now very close to being out of warranty) then even if Volvo cannot fix it there and then they will (or should ) honour the warranty if had to take the car back a couple of weeks later to be fixed but in reality may now be 100km outside the warranty?

I'm at Volvo right now having the deadlock replaced so I asked them. In a nutshell, no courtesy car while the car is waiting for authorisation but they will provide one while the actual repair work is in progress. In the case of my car, authorisation took about 5 weeks and the repair 1 day. (The car stood at Volvo for the 5 odd weeks because it was undriveable)
With regard to the warranty, I’m sure you're right about the fault & warranty time frame. If its identified in time it should be covered. My guess is they're legally liable – and its probably covered in the small print of the maintenance plan.

And thanks for the tips on posting quotes etc. Will give it a go.

[chrisdc]

Originally Posted by Zeb246

Sooo... My mpg has gone down to 20 mpg, it's been 3 weeks since the mpg has decreased. I must of got lucky by bringing the mpg up to 40, when I took her up to London 200 odd miles there and back.

I've booked my car in for the 'free health check' so will inform Volvo about the dreaded mpg, and hope they can find a solution.

Very sorry to hear that. Mines creeping up as well with lots of short trips since that run to the Midlands. Has gone form 5.1l/100km to 6.6l/100km. Still better than it was though, and acceptable for a car of this size with auto and aircon permanently on.

How long did the increased MPG last and how often do you get the "Soot particle filter full" message? Do you do mostly short trips?

[danielg1980]

Originally Posted by Zeb246

I pumped up all 4 tyres to 35psi, but still no luck. Would changing the oil and oil filter help the mpg go back up again? I couldn't seem to find the fuel filter underneath the car. Where exactly is the fuel filter located?

Car look's squeaky clean with the autoglym polish. I think it's time to polish up my car soon with the 3 stage Meguiars polish.

Been on a long run today (85miles there and back) and on second fill up of normal Shell diesel and the trip computer is showing 45mpg average, also my "ENGINE SYSTEM SERVICE REQUIRED" message has finally cleared itself! Got a long journey to the west country next week so I'll brim her and reset both the computer and the trip to work out mpg properly and compare figures.

All in all a productive couple of days, starting to feel more connected to the car more now things are starting to settle down.

Sorry no idea where the fuel filter is, my mechanic changed that for me.

[chrisdc]

Originally Posted by SonyVaio

EGR: If you have a faulty EGR this can have an effect on MPG

Got the dreaded "Soot particle filter full" message again - this a few days after a good long run into the countryside and back. The fuel consumption is steadily deteriorating again.

I'm beginning to think I may have EGR valve issues. Am I correct in thinking that a faulty EGR will (amongst other things) result in premature filling up of the DPF?

The missus is also complaining that the car is becoming more and more sluggish, especially noticeable when pulling away from a stop.

You mentioned in a later post that cleaning of EGR valves is not part of scheduled Volvo servicing. Should this valve be expected to stay clean for 5 years / 100,000km - the duration of the warranty? Do you know of anyone having an EGR valve replaced under warranty?

Thanks SonyVaio, i really do appreciate all the input.

[chrisdc]

Originally Posted by chrisdc

So many people contribute to these forums so it's difficult to know where to start when thanks are due but this particular post got me thinking.

Well, i've just come back from a 260 odd Km drive in the country (a totally nerver wracking experience under the circumstances) and TA-DA!! 5.2l/100km (it flipped over from the 5.1 in the photo while i was taking a shot of the outside of the car). 45mpg !! (28.5mpg before i left)

A VERY BIG thank you to everyone for contributing and for all / and to all the people that make these forums possible.

More to follow....

Errr... just found out UK and US Gallon not the same. Line with mpg in it should read

"54mpg !! (32mpg before i left)" (UK Gallons)

[danielg1980]

Originally Posted by Zeb246

I pumped up all 4 tyres to 35psi, but still no luck. Would changing the oil and oil filter help the mpg go back up again? I couldn't seem to find the fuel filter underneath the car. Where exactly is the fuel filter located?

Car look's squeaky clean with the autoglym polish. I think it's time to polish up my car soon with the 3 stage Meguiars polish.

Changing the filters can't hurt, a good long run certainly seems to make a difference as well. Hope it starts improving soon!

[Zeb246]

Been a while since I last posted here..I mostly do short journeys, or sometimes go on the motorway to get to my destination. So far I've been getting 24.6mpg on short journeys, haven't seen no change since I last drove getting 41.4mpg.
I don't get any messages, or no symbols on the dash. Still haven't replaced the filter, will change it when I get round to it.

Did 260 miles from Bristol to London and back again. Mpg was 41.4mpg speed of 80mph. Since then I haven't been on a long journey.

Overall, I haven't seen no change, no difference in increasing mpg whatsoever.

[chrisdc]

Well, after only 1000km since last service (by Volvo), the "Book service" message is back again. And the car is continually doing regens of the DPF in spite of doing mostly long runs since that service. Volvo have conceded this is not normal (they had a quick look when i took it back for a second faulty deadlock) and its booked to go back again next week. Fuel consumption seems to be settled at 7.2 L/100km. Personally, i think the EGR valve is the culprit - based on many hours of reading these forums. Will post back after they give me their findings.

[SonyVaio]

Well with constant regens it either means that the DPF is indeed blocked or you may have a faulty sensor indicating the DPF is blocked and thus causing the regens?

[v50inred]

Glad I fluked it and bought one with no DPF. Was a fluke aswell as I never even checked if it had one, went to the auction to buy a Mondeo estate!