25 mpg 1.9dci

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cushdy
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Joined: Mon Jun 28, 2010 7:15 pm

25 mpg 1.9dci

Postby cushdy » Mon Jan 10, 2011 10:18 pm

hi hope you can help ive a megane 54 plate starts 1st time drives well got 92k miles on the clock had it about 8 months now when first got it i was getting around 40mpg which dropped to 32 now its at 25mpg only fault that comes up is check injectors but this goes off after a restart when warm thanks in advance

davelowe
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Joined: Thu May 10, 2007 3:40 pm

Re: 25 mpg 1.9dci

Postby davelowe » Mon Jan 10, 2011 10:34 pm

Clean the breather system and check the PCV (round thing on top of the engine with rubber hoses in and out). Clean the EGR. Service the car (including the oil, diesel and air filters + new oil - Mobil 1 0w40). Check each glowplug resistance is 0.6 ohm. Replace any that are duds. The message is 'Check Injection' and covers many faults (although glowplugs are the favourite). Get the codes read using an OBDII reader such as ELM327 from ebay (£30). Check the turbo actuator move freely by hand. Run the engine and unscrew the dipstick - does it blow a lot of smoke out? If so you may have stuck (or failing piston rings).

All of these things have been posted about many times - please have a search for the individual items.
Silver 08 plate 5dr 1.5dci Dynamique 106 Tech Run (re-mapped)

Red 03 plate 5dr 1.9 Dynamique dci120

Best advice for Megane owners: sell it before it bankrupts you!

cyclonebri1
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Currently Drives:: Badly

Re: 25 mpg 1.9dci

Postby cyclonebri1 » Tue Jan 11, 2011 9:30 am

All that Dave says is correct with the exception of the glowplug bit. These are not in circuit once the car has started and cannot effect running, only cold starting.

As an example, my daughters megane had 4 open circuit glowplugs when I checked them, and the only symptom was a puff or two of smoke on start up. It was still returning 55 to 70mpg (1.5dci) :cool:

cushdy
Posts: 3
Joined: Mon Jun 28, 2010 7:15 pm

Re: 25 mpg 1.9dci

Postby cushdy » Tue Jan 11, 2011 3:32 pm

cheers just took my egr valve off and it was well coked up so will leave it in some alloy wheel cleaner overnight see if that does the trick

davelowe
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Re: 25 mpg 1.9dci

Postby davelowe » Tue Jan 11, 2011 10:41 pm

cyclonebri1 wrote:All that Dave says is correct with the exception of the glowplug bit. These are not in circuit once the car has started and cannot effect running, only cold starting.


The glowplugs continue to operate when the engine is cold and warming up. There is a regulator for this purpose. The 1.9 engine will start from cold without any working glowplugs, however.
Silver 08 plate 5dr 1.5dci Dynamique 106 Tech Run (re-mapped)

Red 03 plate 5dr 1.9 Dynamique dci120

Best advice for Megane owners: sell it before it bankrupts you!

Husky_Dog
Learner Driver
Posts: 79
Joined: Mon Oct 24, 2005 1:43 pm
Location: Norwich, UK

Re: 25 mpg 1.9dci

Postby Husky_Dog » Wed Jan 12, 2011 7:10 am

davelowe wrote:
cyclonebri1 wrote: The 1.9 engine will start from cold without any working glowplugs, however.


But will drastically reduce the battery life = False economy... :!:
2005 Scenic 1.9Dci 120 Exception

cyclonebri1
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Re: 25 mpg 1.9dci

Postby cyclonebri1 » Wed Jan 12, 2011 9:56 am

davelowe wrote:
cyclonebri1 wrote:All that Dave says is correct with the exception of the glowplug bit. These are not in circuit once the car has started and cannot effect running, only cold starting.


The glowplugs continue to operate when the engine is cold and warming up. There is a regulator for this purpose. The 1.9 engine will start from cold without any working glowplugs, however.



Agreed, but it won't radically effect fuel consumption. I was simply saying it will not be the cause of such a drastic reduction in MPG.

Regarding the last posters coment about battery load. The car I spoke about stated 1st turn on the key with 4 dead glowplugs, thje only clue was about 5 seconds of smoke on starting so it's not a given.

cushdy
Posts: 3
Joined: Mon Jun 28, 2010 7:15 pm

Re: 25 mpg 1.9dci

Postby cushdy » Wed Jan 12, 2011 3:45 pm

dont need an oil change for 3000 miles yet air filters ok there is a bit of smoke coming from the dipstick but not much? cleaned the egr and took it for a run got 58mpg on the motorway at above mph got back home it was at 43 will have to see what it settles down to so cheers again

cyclonebri1
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Re: 25 mpg 1.9dci

Postby cyclonebri1 » Wed Jan 12, 2011 4:59 pm

cushdy wrote:dont need an oil change for 3000 miles yet air filters ok there is a bit of smoke coming from the dipstick but not much? cleaned the egr and took it for a run got 58mpg on the motorway at above mph got back home it was at 43 will have to see what it settles down to so cheers again

Doesn't sound too bad then. You have to bear in mind the very cold recent weather. Larger diesel engines are notoriously slow in warming up do th their efficiency. Next time you check your routine mileage do it on a typical trip but reset the computor only after the engines had say 5 miles warm up. May give a clue.

davelowe
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Joined: Thu May 10, 2007 3:40 pm

Re: 25 mpg 1.9dci

Postby davelowe » Wed Jan 12, 2011 10:36 pm

cushdy wrote:dont need an oil change for 3000 miles yet air filters ok there is a bit of smoke coming from the dipstick but not much? cleaned the egr and took it for a run got 58mpg on the motorway at above mph got back home it was at 43 will have to see what it settles down to so cheers again


Sounds good. Best on mine is driving at 30mph in circles - it will just about touch 60mpg. 58mpg is fine.

Out of interest I regard 3000 miles as an oil change interval!
Silver 08 plate 5dr 1.5dci Dynamique 106 Tech Run (re-mapped)

Red 03 plate 5dr 1.9 Dynamique dci120

Best advice for Megane owners: sell it before it bankrupts you!


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