Poor mpg on a 1.4?

[steve_1017]

And its really poor! i'm getting about 40 miles on £15 of petrol around town. Any suggestions as to what may be wrong? Or are all the 1.4's like this? i cant remember it being this bad when i first got it. Any help would be appreciated.

 

[F2 Ed]

without using a calculator, thats got to be less than 15mpg

The 1.4 doesn't have a mass air flow sensor so its not that

Lambda sensor could be the cause, or less likely the coolant temp sensor. These things all control fueling

 

[steve_1017]

A trip to Gsf might be in order then, any ideas on prices for those two items?

 

[Dolly_Gti]

as above those 2 sensors.

would think about giving it a full services, air filter/spark plugs, tyre pressures ect will make a difference.

 

[steve_1017]

Serviced her a few weeks back, well, apart from the fuel filter, thats still sat on my bookcase. Did oil and air filters, plugs, cap and arm. i'll get these sensors and chuck them on too, hopefully will make a difference

 

[Dolly_Gti]

lambda sensor probably wont be that cheap.

coolant temp sensors are usually cheap from VW, wouldnt get a gsf/non oem sensor as prone to failure.

 

[F2 Ed]

lambda is most expensive, about £50 or so (aftermarket, not genuine)

Coolant temp sensor will be less than £30. Normally when this one is faulty it will also make the car idle higher than normal.

 

[ibizaboi]

are the coolant temp sensor called temp tramsmitters?

 

[F2 Ed]

sometimes yes, but don't confuse it with a temperature switch

a temp switch / fan switch just controls the cooling fan on the rad

 

[ibizaboi]

kl have u got any part numbers?

 

[Gordz]

And its really poor! i'm getting about 40 miles on £15 of petrol around town. Any suggestions as to what may be wrong? Or are all the 1.4's like this? i cant remember it being this bad when i first got it. Any help would be appreciated.

In my 1.4 (I assume it's the same 8v one that was used in the mk3) I too had very low mpg, but seemed to be normal when chatting on here about it

I was getting around 20 - 30 mpg depending on the hills! lol. It's just a crappy engine.

I did have emissions problems though, but all sensors were fine! Main reason I got rid in the end, as was costing more to run than my 1.9 tdi I have now!!!

 

[F2 Ed]

I clocked the 'round town' mpg on our silver 1.4 mk3 at work and that gets almost 40mpg

 

[markmeus]

My mk3 would average around 35 - 40, but take it anywhere near a motorway and it was more like 30-35

 

[Gordz]

I clocked the 'round town' mpg on our silver 1.4 mk3 at work and that gets almost 40mpg

Yeah, town driving it was brilliant, needle wouldn't move for days on end when pottering around Bangor!

My mk3 would average around 35 - 40, but take it anywhere near a motorway and it was more like 30-35

That's why my mpg was so shocking! I did do quite a lot of motorway / dual carriageway miles and was costing me a fortune!!!

 

[CraigW]

Even on A roads I get good mpg in my 1.4, but like markmeus said as soon as I go onto a dual carriage way or motorway it isnt very good.

 

[steve_1017]

Seems like my car is a piece of junk then, i'll get the lambda sensor looked at and hopefully stop throwing money down the drain

 

[steve_1017]

Would cleaning my throttlebody (again) help me get better mpg?

 

[Gordz]

Would cleaning my throttlebody (again) help me get better mpg?

I'd have thought if you've already cleaned it then cleaning it again wont make much difference?

You could try cleaning engine out with some of those engine flush / cleaner things you can get in Halfords?

I used some Wynn's stuff and actually was really good and made the engine run much smoother, and probably did increase mpg a little.

 

[steve_1017]

it was about 2 years ago i think, and the revs are starting to dip when i'm sat at traffic lights again. Might do it at the weekend with the fuel filter if i can muster enough enthusiasm