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The mkiv Supra Owners Club

bad fuel consumption on E46 BMW


Lude

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its a 2001 316ti

 

 

no warning lights have come on, but its going through loads of fuel!

 

 

before i buy loads and loads of parts, which i may not need, is there any way of finding out? or shall i just buy the following and hope for the best?

 

o2 sensor,

spark plugs,

fuel filter

 

check for vacuum leaks

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our 330i gives 26mpg in london which I think is pretty good. The supra in comparison averages 18mpg (which i think is amazing for what it is) :)

 

on the motorway however the BMW easily acheives mid 30s...

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Have you run it for error codes? You can get basic BMW diagnostic code readers for about £20 off ebay. Could be loads of different things, but that'd be my first move.

 

http://www.ebay.co.uk/itm/U480-Universal-OBD2-CAN-BUS-Fault-Code-Reader-Scanner-diagnostic-scan-tool-U-480-/320907644060?pt=UK_Diagnostic_Tools_Equipment&hash=item4ab7960c9c

 

I've a few different types, some basic and some quite advanced stuff. This will tell you if the ecu's pulling up any codes etc, basic but does the job. :thumbs:

 

 

O2 sensor or a dodgy spark plug would trigger the Engine management light, so I doubt its that.

Edited by nige-rz (see edit history)
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Not necessarily no. Intermittent fault codes won't always trigger the engine management light, specifically on older e46 models, from my experience. (newer e90/e92 3 series and e60/61 5 series are much more sensitive and have numerous engine diagnostic and performance sensors) It's 13 quid well spent in my opinion to run the fault codes. It's the first thing any garage will do to diagnose the problem.

 

Alternatively, go to an independent and pay 60+ for them to diagnose the problems, or take out a 2nd mortgage and go back to the main dealer.

 

Are there any other symptoms? When you say poor fuel economy, what mpg specifically is it doing?

Edited by nige-rz (see edit history)
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£90 inc vat for a full diagnostic at my local BMW dealer so hardly a remortgage :)

 

I was basing my figures on Irish BMW main dealers. I paid 170+vat (euro) to diagnose a seat occupancy sensor problem on my old e60. It was the cheapest quote I got from 5 dealers. My point was he can do it himself if he spends £13. :thumbs:

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thanks for the input guys,

 

ive just purchased the reader code from ebay. will report back next week.

 

only symptoms i have is its really heavy on juice, my mrs drives it so i dont know the exact mpg.

 

she says its gone so bad it she can nerly watch the needle moving.

 

she has said theres no power in it, but this has been like this from when we had it. my mate also said that those models have no power in them anyway so im not to bothered about the power of it. but the fuel consumption NEEDS to be good.

 

 

just for the record id never buy a BMW lol, dont think they are quality at all

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UPDATE

 

i purchased the Diagnostic machine, well impressed with it! :) £16 delivered from ebay.

 

car has 3 errors

 

1) P0015 - Camshaft position A actuator B-Bank timing over retarded

 

2) P0366 - Camshaft position Sensor B Bank 1 CKT Range/Performance

 

3) P0050 - HO2S Bank 2 Sensor 1 heater circuit

 

 

SOLUTION?

 

 

P0050 - think thats just replace the O2/lambda sensor

 

what about P0366 + P0015 though?

 

is it the sensors which are broke? or is the timing out?

Edited by Lude (see edit history)
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