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Poor Fuel Consumption on 2.4 Auto

danny35 said:
Thanks for the reply. I wouldn't mind 20mpg so much, but it includes me driving with a light foot and with minimal traffic. I dread to think of the MPG when I drive more spiritedly and get caught in normal traffic. I was hoping for 25mpg on this tank and 20mpg driving more spiritedly with normal traffic.
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Actually, I'm not convinced that driving a cold engine with a light foot will make much difference. It could be argued that the engine takes longer to warm up, so therefore a heavier foot might work counter to common-sense. It depends on the fuelling map as to how the engine performs when cold. With a carburettor (they don't have "lean-burn" regions) in my experience it would not make any difference on a cold engine, except high rpm and very wide throttle openings.

Maybe try filling up again now, make a note of the litres and miles, then reset the trip meter and try a bit more right foot to see if it makes no difference.


I've also had another look at the list in your initial post, here it is again ....
- Clean MAF sensor & EGR
- Calipers (though I think they should have been checked already)
- UN-metred air in the system
- 02 Sensor
- Clean throttle body/sensor
- Wheel Allignment
- Tune up
- Pipes for damage
- Air filter connection hoses.

When was the last time that these were checked (these also likely to affect mpg)
- spark plugs
- valve clearances
 
freddofrog said:
Actually, I'm not convinced that driving a cold engine with a light foot will make much difference. It could be argued that the engine takes longer to warm up, so therefore a heavier foot might work counter to common-sense. It depends on the fuelling map as to how the engine performs when cold. With a carburettor (they don't have "lean-burn" regions) in my experience it would not make any difference on a cold engine, except high rpm and very wide throttle openings.

Maybe try filling up again now, make a note of the litres and miles, then reset the trip meter and try a bit more right foot to see if it makes no difference.


I've also had another look at the list in your initial post, here it is again ....
- Clean MAF sensor & EGR
- Calipers (though I think they should have been checked already)
- UN-metred air in the system
- 02 Sensor
- Clean throttle body/sensor
- Wheel Allignment
- Tune up
- Pipes for damage
- Air filter connection hoses.

When was the last time that these were checked (these also likely to affect mpg)
- spark plugs
- valve clearances
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Hi Brian, Thank you for your detailed reply. I will have check the mileage again using my normal heavy foot driving and see.
I have had a service recently and the mechanic said that he didn't change the spark plugs as thy were fine, so I hope he was telling the truth. Regarding the original list that I mentioned and the 2 items spark plugs and valve clearances) that you mentioned, I would have to get these checked out with a mechanic as I am not very handy in this area unfortunately. Do you have any idea how much labour would be involved carrying out that list with your 2 items included (***uming ofcourse that there are no additional problems)?
 
if he said that the plugs were ok, then they probably were. Regarding valve clearances, not sure of the labour time, probably about 1 hour.
 
freddofrog said:
if he said that the plugs were ok, then they probably were. Regarding valve clearances, not sure of the labour time, probably about 1 hour.
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One hour for valve clearances alone-mmmm. I am then ***uming that getting that whole list done is going to be very expensive. I do wish I was more handy with these things.
 
sorry if the following sounds like the spanish inquisition, but ....

What is down as being done on the full service (that you mention in your first post) ?

Was it done by the place you bought the car from ?

Was the place a Honda dealer ?

Does the car have a full service history, if so is it a Honda service history ?

Did you get old service paperwork with the car ?
 
freddofrog said:
sorry if the following sounds like the spanish inquisition, but ....

What is down as being done on the full service (that you mention in your first post) ?

Was it done by the place you bought the car from ?

Was the place a Honda dealer ?

Does the car have a full service history, if so is it a Honda service history ?

Did you get old service paperwork with the car ?
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1) The mechanic who carried out the service was an independent mechanic recommended to me by my Dad. The problem I have is that I never got a list of what was carried out in the service so wouldn't be sure. It was a mistake going there in hindsight.

2) I bought the car privately, however the guy I bought it from had an MOT carried out about a month before.

3) NO

4) The car had a full Honda Service History up until 2013, then missed 2 services and only 3 weeks ago had another full service from an independent dealer.

5) I did get some paperwork with the car and have breezed through it, but not looked into it in great detail.
 
I think that the 75k service includes a check on the valve clearances (I'll have to take a look to verify), what was the mileage on the last Honda service (2013)

It might be worth calling a Honda dealer for a quote on a full service that includes valve clearances, would be about £300 I reckon
 
I have just checked the service book. There were 2 services carried out at Ruislip honda, one was on 2012 on 75,558 miles and the other 2013 on 78,960 miles.

I don't think I can afford to pay £300 for another service.
 
ahhh, one of those should have included valve clearance check (if you have the same service book as mine, then it''s in the 12,500 mile list on page 37)

probably not worth going back to a Honda dealer

just stick with where the thread was up to at the first half of #31
 
That's a relief!. Thank you so much for your help, Do you still think I should carry out the rest of the list, and if so, do you think it would take quite a few hours to get through?

PS: I don't think I have the same service book as you by the looks of it.
 
I have been reading up about valve clearances and it seems it is an optional extra during a service. If so, how would I know if it has been carried out as I can't see any evidence in the documents.
 
danny35 said:
That's a relief!. Thank you so much for your help, Do you still think I should carry out the rest of the list, and if so, do you think it would take quite a few hours to get through?

PS: I don't think I have the same service book as you by the looks of it.
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If you think you're up to doing the things in your own list, you could check them, can't say how long it will take you though (btw, no EGR on the 2.4 petrol).

Best to start with the rear brakes, they are terrible for binding on the Tourer, not so much of a problem on the saloon.


danny35 said:
I have been reading up about valve clearances and it seems it is an optional extra during a service. If so, how would I know if it has been carried out as I can't see any evidence in the documents.
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It says "inspection" in my service book (every 25k miles allegedly). Time-wise I don't know how "inspection" of valve clearances would differ from actually making any adjustments, so I ***ume that inspection and adjusting are the same. No evidence that this was ever done on my car either (I stopped taking it to Honda when it reached about 70k miles).
 
I just refilled up the tank and my exact MPG is 152 miles / 8.21 Gallons = 18.51 MPG.

That is disappointing as my journeys on the 152 miles has been relatively smooth and traffic free, and as I mentioned previously without driving aggressively. I was hoping for 22-25 MPG.

I guess my next step is to get things on my list seen to:

- Clean MAF sensor
- Calipers (though I think they should have been checked already)
- UN-metred air in the system
- 02 Sensor
- Clean throttle body/sensor
- Wheel Allignment
- Tune up
- Pipes for damage
- Air filter connection hoses.

I don't think I can afford to get these all done at the same time as it would be quite expensive, so any recommendations of which ones to go with first would be appreciated. Also, is there any simple way for me to rule out any of the issues on the list above?

Kind regards,

Danny
 
That was about 37.3 litres ?

The one that costs nothing to check is the calipers, you can jack the car up and check that the wheels rotate freely. Try it before and after a journey.

Next is Hunter 4-wheel wheel aligment (presuming it's saloon btw).

One other point, does it ever reach normal operating temperature, if so, how long (in miles) does it take ?
 
Yes 37.3 litres to be precise,and it is a saloon. When the engine is warmed up, it goes up to a few millimetres before the half way line. The car warms up in about 3 - 5 minutes of driving and stays around there permanently. It doesn't reach the half way line though, but I have ***umed that this is normal.

When I carried out the pre vehicle inspection, I saw the mechanic ramp up the car and rotate the wheels and he said it was all good. I am not sure if it looked like the front wheels rotated more to my eyes then the rear wheels, but I am not sure if I was just imagining that. Also I would ***ume that the callipers would have been checked during the full service.

Regarding the wheel alignment, again the mechanic in the pre vehicle inspection said that it was okay, however I am not quite sure how he could have been certain as he said that before even test driving the car.
 
The warming-up sounds about right.

Best way to check the calipers on each wheel, is with an ***istant in the driving seat with engine running (in neutral). With the wheel off the ground, rotate the wheel by hand, get the ***istant to put their foot on the brake and then release, then see if the wheel still rotates as it did before. Nothing else is as good :(

Wheel alignment can only be checked on the Accord saloon by using Hunter 4-wheel. Nothing else is as good :(
 
Thanks! I don't have a jack for the car so would have to take it somewhere to check. I would be very disappointed if both the pre vehicle inspection mechanic and the mechanic at the service didn't check that. Regarding the wheel alignment, I will take it in maybe to a guy nearby who has the Hunter machine. I don't feel any shaking when driving at 80+mph and the steering does sometimes tend to veer either to the left or right but that can't be alignment as it is on both directions.

I am thinking maybe to also get the maf sensor and Throttle body cleaned at a mechanic and perhaps for them to check the 02 sensor, pipes and hoses as these could make a big impact. I will need to get an estimate on this and hope it's not too expensive.

If anyone by any chance knows of an affordable mechanic familiar with Hondas in the London area, that would be great.
 
Generally, mechanics do not have an ***istant sitting in the passenger seat, unless they really need it.

Steering veering to left or right is an indication of poor 4-wheel alignment on the Accord.

One other thought, did anyone check to see if there are any codes (using an OBD reader, or better still, a Honda HDS) ?

There are two sensors in the exhaust on this engine btw : LAF sensor (lean air-fuel, aka wideband), and a standard oxygen sensor (aka narrowband). OEM price for each is the same, £225. Part number for former is 36531RBB003, for latter is 36532RADL12

tbh the best way to check for any issues other than wheels, is with a Honda HDS
 
Yes, the mechanic at the pre vehicle inspection and the one that carried out the service connected the car to the reader and went through all the readings. They said everything was good.

I didn't know that the steering veering to both sides would be a sign of bad alignment. I thought alignment was only to one side. I guess I will have to take it to the hunters mechanic this week to get it checked out. He will probably say I have bad alignment either way so that I carry out the work.
 
If there were no codes then tbh the only way is to connect a proper diagnostic system (such as Honda HDS) and take the car for a test drive. Things such as fuel trims can then be determined, and from that, the reasons why it is running slightly rich.

Hunter alignment system is used to determine the amount of mis-alignment, and to check while the corrections are made. They do it all when the car is there. http://www.hunter.com/alignment-systems
 
danny35 said:
Would only Honda have that proper diagnostic machine?
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yes, although you can buy Chinese clones on eBay for £80 to £90 (search for "Honda HDS HIM" on eBay). AFAIK these clones all run on XP and if you don't have built-in RS232 on any PC/laptop you'll need a USB-to-RS232 adapter cable (some of the eBay sellers include an adapter cable).

A couple of other things that can cause poor mpg
- high fuel pressure
- poor injector(s)
- carbon build up (usually due to car having been run on 95 RON supermarket fuel)

Apart from issues with wheels and carbon build-up, a Honda HDS can help to diagnose issues (I have one myself, but I live a couple of hours drive from London).

Depending on the fuel trims, even an expert with a Honda HDS may not come up with anything obvious I'm afraid.
Otherwise it's definitely going to be trial and error on everything on your list, and if you're going to pay someone to do the work, it could be a money drain which is more than the loss in mpg.
 
btw, if you want a recommendation on a good Honda independent in London, I've seen it asked before, usually in "Honda Accord Chat" section. If you can't find anything, maybe ask in that section.
 
I've actually just realised something! When I bought the car it said 16 inches tyres on the advert, but upon checking now, I actually have 17 inch tyres.

The standard 16 inch tyres for the accord would be 205/55 R16 91V
The tyres that I have are 225/45 R17 91Y.

Overall Tyre Diameter difference is not much. It is 24.88 for the 16inch Tyres and 24.97 for the 17inch tryes.

Could this be a reason for the lower MPG figure that I have been getting?
 
ukcl9 said:
no.

i would reset your ecu.you can do it yourself.see if it makes any differance.your mpg is very bad

sadly i dont have anymore a spare auto ecu to see if it makes any differance

could be faulty 02 sensor
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Hi, just to clarify, can the readings to test the 02 sensor and the 2 lamda sensors, both front and rear be read without an official Honda diagnostic machine? I would prefer not to have to go to a main dealer or buy the machine myself.

Also, how would I reset the ECU?
 
Booked in a mechanic with an official Honda Machine for 18pm later today. Will post back with the results.
 
Keep the faith, these are terrific cars, it will serve you well after you resolve this.

I agree it sounds maybe lambda sensor related, but no point throwing parts at it unless you know for definite.
 
Hi all, well I had the diagnostic check done, the guy was extremely thorough and spent over one and a half hours to going through everything. He also had the official Honda Diagnostic machine/software which was great. He did find 4 main codes which he re-calibrated and fixed. One was the Lambda Sensor which was apparently pumping a bit too much fuel to the system. The others were injectors and something else which has just skipped my mind, so I hope these help with some of the fuel consumption issues.

After he reset and calibrated the codes the engine noise sounded slightly quieter I think which is good. He also said that the Spark Plugs should be changed as he could hear them misfiring. Can anyone recommend the best sparkplugs for me to get or are they all the same?
 
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