Peugeot 306 - Help with poor fuel economy on 306 hdi | Technical matters | Back Room Forum

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Tue 15 Mar 2011 19:39

Peugeot 306 - Help with poor fuel economy on 306 hdi - scfc_151

took my car in for a diagnostic and had a new battery, MAF sensor and fuel pressure regulator.

The car feels better than ever to drive, nice and smooth and feel like some of the power is back.

However, i usually got around 600-650 from a tank so I averaged 45mpg.

Now ive noticed when I brim the tank im getting around 500miles.

Ive checked that there are no fuel leaks, brakes binding etc and the car recently had a full service so what could the problem be?

Ive also noticed a high pitch whistling when driving at around 30-40mph.
This only happens when the revs are constant and goes when I accelerate or decelerate.

I dont know if this is related to the leaking intake manifold that I repaired in my last post

thanks

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Tue 15 Mar 2011 22:28

Peugeot 306 - Help with poor fuel economy on 306 hdi - Peter.N.

To do an accurate fuel consumption check you need to fill the tank to the brim, then do the same again at the next fill and calculate the consumption. The onboard computers are generally pretty good but allways to be relied on.

The whistling noise you mention could be due to a leak in the air intake somewhere between the turbo and the inlet manifold, this could result in an increased fuel consumption but also in reduced performance. If the high pressure air from the turbo is not all reaching the engine the efficiency is reduced.

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Wed 16 Mar 2011 19:22

Peugeot 306 - Help with poor fuel economy on 306 hdi - scfc_151

Thanks for the reply, the miles per tank where brim to brim figures as my car doesnt have an on board computer

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Wed 16 Mar 2011 19:26

Peugeot 306 - Help with poor fuel economy on 306 hdi - scfc_151

Thanks for the reply the figures quoted were brim to brim as my car doesnt have an on board computer

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