Hi, I have got a 1.6tdi 105bhp monte carlo. I have just had the wiring harness replaced under warranty, due to the fact that the glow plug warning light kept on flashing. The light hasn't come back yet, however the mpg is really poor now. Anyone else had the same problem?

Edited 9 February, 201412 yr by Mat2113

Welcome to the forum, 

sorry i know nothing about Diesels or Manuals, but to help people answer.

 

Were do you drive, how many miles per trip a day, long trips,  short trips?  

& what sort of MPG are you getting?

 

What were you getting before?

hi, before the loom was repalced i was get about 45-50 mpg. now it about 38 mpg and thats on a a roads.The dealership reporgramed the ecu.

How far have you been in it since getting it back?

Are you calculating this yourself, or by using the car readout?  I have the 75hp version of the same engine as yours - the car tells me I'm getting 40mpg, but I calculate 55mpg (by resetting the trip every time I fill up etc etc) - I think quite a few people have wonky figures from the car calculated MPG as well...

I use the car readout on the car.

Might be worth calculating it yourself for a few tanks, to see what's really going on.  I started doing this a while ago, and it makes me happier than looking at the car readout... I've got a bit pedantic about it now, even got a pad to note it down and see how it changes over time... I should get out more...

I've had the loom replaced when my Monte went in for the service re-set (4th time lucky) and did notice a drop in mpg but I've put it down to my winter tyres but I still get an indicated 55 mpg for my short journey to work (12  miles) although this will drop to 40-45mpg in town.

Either keep track with Fuelly (click my Sig below), or if you have an android phone, have a play with: https://play.google.com/store/apps/details?id=com.auto_m8.uk (my current choice which is backed up online), https://play.google.com/store/apps/details?id=ch.simonmorgenthaler.fuellog (what I used too use!!)...

 

My Maxi-Dot tells me I'm getting on average 64mpg and both the above tell me 63mpg so the computer isn't too far off

That figure sounds low, but is it No1 Average Economy readout or No2?  Is it MaxiDot or MFD?

 

On MFD (that I have on Monte TDI 105) on Average Economy screen, press the button under the right hand stalk - this switches between Average economy for trip (no1) and average economy for 1000 miles (I think - No2).

 

It may be that the no1 screen is reading accurately, thanks to a reset and the No2 is still showing a reasonable economy.  It may be off for some reason.

 

Not to suck eggs:

 

Always best to do a manual back up - fill tank to brim, zero trip meter, drive to empty, fill again.

 

Take amount of fuel added (note it from pump or on receipt) and convert to gallons (take litres value, divide by 4.54).  Memorise that figure.

 

Take your trip distance and divide by the Gallons figure you saved/memorised.  Voila - Miles per Gallon.

I always zero my trip after each fill up. I normally get about 480 miles from a tank of Shell regualr diesel on more day to day running.

 

More on if I have a long journey and significant more when the weather is warm. Seems these days fuel consumption is effected by so many factors. Heavy rain and lots of surface water makes a big difference too!

Same here. 480-500ish miles to a tank in this weather. Hopefully better in summer (not had it long).

Computer shows 58mpg average over all my journeys (mostly motorway).

Just returned close to 620 miles on a tank but then I'm pootleing about in a Greenline, not a Very Rapid Skoda or Monte like you lot! :(

now covered 26K miles in my TDI 105.

Fantastic MPG ! seems to be still improving. filled up yesterday (132,9 per litre, Esso in mansfield, cheapest I've seen!) and the tank distance reading was 655 miles!!  Most of my driving is motorway so obviously at constant speeds It does pretty well, but I never average below 52 mpg.

 

Had the car from new Oct 12 when at that time a full tank only registered 400miles distance!

Edited 12 February, 201412 yr by charles

Thanks for all the replies. I have run the car all week up and down a roads, I have just fill it up with shell v power. I have just worked the mpg out at 41 mpg. The car has a maxi dot display and tells me to put the car into fifth gear, but when I do the car judders. I have just phone my local dear, so see about booking the car back in. So I will have to wait to see what the say.

Edited 12 February, 201412 yr by Mat2113

Should be fine in 5th from about 55mph. Below that, and it struggles.

I've done nearly 45k in my revo remapped 1.6CR Scout, it hardly get's used in town, but the best figure I have had was 720 miles on a tankfull brimming it, from home to Aberdeen and back, trip computer reckoned I was getting 53mpg so it was lying like a cheap naafi watch That was the best, I normally get between 600 / 650 miles on a tankfull.

 

MPG has greatly improved with getting miles on it