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Discussion Starter · #1 ·
I remember reading about some of the possible causes of poor fuel economy in a 1.8T were down to the MAF, another sensor (can't for the life of me remember what it was), a lead foot.........etc

Mine is probably a lead foot but out of interest what was this other sensor? I seem to remember people recommending it be changed for a "green" version??
 

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Discussion Starter · #3 ·
Quote: posted by MikeP on 01/01/2005 17:40:26

Was it not the lambda probe which sits in the exhaust?

Thats another reason for poor MPG but not the one I was thinking about.
 

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I'd like to know too.... it's getting booked in at the dealers for a whole host of problems including poor mpg. It struggles massively to get anything above 26mpg...
 

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Discussion Starter · #5 ·
I beginning to think I have imagined seeing details of this other sensor!!

Your seeing figures very close to mine Chris but as yours is still stock then its a little worrying.
 

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I know!

I do an awful lot of driving through town, but never sitting in traffic. I know its a more powerful car than the GTI i had, but on a regular day to work i could get anything upto 39mpg taking it easy. I cannot even when driving like a granny, get this thing to hit 30mpg!
 

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i only get around 25/26 mpg.what should it be?

one sensor that was mensioned a couple of weeks back was the air temp sensor on the inlet manafold,i cleaned this and its no better.

jase...
 

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Discussion Starter · #11 ·
Quote: posted by Badger5 on 01/01/2005 20:24:01

Green sensor? You mean a water temp sensor perhaps?

LOL, I really have no idea.

Its just something I read a few days or so ago which didnt sink in at the time.

That wouldnt have any effect at all on fuel consumption would it?
 

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I remember something about a green sensor as well, or at least that's the colour of it... it's got me stuck now!
 

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Coolant temperature sensor.

If it's reading low, the car runs a little richer than it should, as it thinks it's still warming up. You tend to get some part throttle surgeing aswell, plus it'll idle crap.
 

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Discussion Starter · #14 ·
Quote: posted by Wilko on 01/01/2005 21:15:49

Coolant temperature sensor.

If it's reading low, the car runs a little richer than it should, as it thinks it's still warming up. You tend to get some part throttle surgeing aswell, plus it'll idle crap.

Thanks John, thats the end of that little puzzle then.
 

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I was getting bad MPG as well so I changed my coolant temp sender two weeks ago, and the idle went rock solid, where before it was a little rough at idle, luckily i went to see PJ in ilford, (top bloke), who vag commed my car, and behold, the coolant sender was showing up, when he reset the code and i test drove the car, it was as if he remapped my car, if flew!!!!!, anyway changed the temp sender and now the engine idles perfectly, and has good MPG to boot!, also the temp needle in the cluster may be erratic, this is a tel tale sign of the sensor going, its very easy to change as well, loosen the expansion cap ,to relive some pressure, just take the engine cover off, and undo the electrical connection from the sender which is on the right side of the engine, then pull out the big plastic circlip, and just ease the sensor out, then use a new o-ring and insert the new sensor back in, and clip the circlip back in , job done!!.
 

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just realised after your explanation i think ive had this changed

a few month ago at jbs as the temp gauge was not reading at all.

is this the sensor?

jase...
 

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Cold starts, under 5 degrees, has been the cause for me. Perfectly normal when its a little warmer. Looks like that drops about 5mpg over a full tank
 
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