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Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 22897
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I haveVW Passat Reg. No. W731UPU year 2000> I service the car

Customer Question

I haveVW Passat Reg. No. W731UPU year 2000> I service the car every year. I have very big problem my fuel consumption is very high I make ($) litres to Mile. I don't know the reason Please help, thank you and kind regards George
Submitted: 2 years ago.
Category: Car
Expert:  Matt replied 2 years ago.
Hello This could be a number of things:Incorrect fuelling due to a faulty water temp sensor. If this is the problem then the ECU will be leaving the car constantly ' on choke' and not reducing the fuelling as the engine warms - so unplug the sensor and clean the contacts on both sides with some switch / electrical cleaner (not WD40) and inspect the wiring for any signs of damage to the insulation especially where it runs over other components and through the bulkhead- if this doesn't help consider replacing the sensor as they're not expensiveCheck for exhaust leaks before the O2 sensor as if this has been experiencing an exhaust leak then it will have been running very rich as the sensor will see the extra air pulled in as fresh / lean fuelling and be adding fuel to compensate. this can lead to catalyst failure as the extra fuel can re-light inside and melt the catalyst The best way to find an exhaust leak is to run the engine from cold and feel around the exhaust joints with your bare hands - you'll have about 30 seconds before it all gets too hot and you should feel any escaping gas blowing over your fingers One other thing is to ensure that you're running on the correct grade of engine and gearbox oil as if its too thick or overfilled this will really hurt the fuel economy Air leak at the mass airflow meter -Any air dragged after the meter isn't 'seen' by the ECU and so not compensated for, causing rough running.Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best way to locate a leak is to have the engine running and warm and then spray lighter gas around each joint in turn. If the engine rev's up you've found your leak.Binding brakes:Check that all the wheels can be turned freely by hand, and free off any sticking calipersIncorrect wheel alignment:Check all the tyres for signs of uneven wear if it has any then get it checked out at a place that does 4 wheel alignment not just front tracking and ensure tyres are pumped up to their recommended maximumInjectors are clean and not dribbling - add a bottle of injector cleaner to the tank Use good quality fuel - from my own findings its worth paying the extra for BP or shell as typically you'll get another 10% fuel saving which outweighs the cost over supermarket fuel.
Expert:  Matt replied 2 years ago.
Hido you still need help?Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. I am only paid for my work on this question if you rate my answer, using the star system at the top of the screen. Please do not forget! Thank you
Customer: replied 2 years ago.
Thank you for answering my question. I took your explanation to my mechanic and we did everything you asked us to do and I spend a considerable amount of money , unfortunately I still have the same problem. Your instruction it didn't solve my problem, tell me what to do next or please refund my money £27.00.I look forward to hearing from you at your earliest convenience. Kind regards George
Expert:  Matt replied 2 years ago.
Hello George sorry to hear this is still a problemcan you tell me just how many miles to the gallon you are getting?
Customer: replied 2 years ago.
I am using 1 gallon to the mile. I told this in my request. As I told you I spent a considerable amount of money following your instruction and nothing happened I still use one gallon to the mile.I am very unhappy with the while situation. For your information I can not afford to spend another £13 for phone call. I am not a mechanic calling you is a waste of time for both of us. Please tell me what to do next. otherwise please refund my £27,00 thank you and kind regards George
Expert:  Matt replied 2 years ago.
Hello George your original request showed a $ instead of number so I was confirming that it actually is this high so for it to be using this much fuel its unlikely to be something very simple, is the car a manual or automatic? Are the brakes binding at all?is this fuel consumption measurement taken off the dashboard or have you done a tank to tank fill and calculated it from the mileage ? as it should be a 62 litre tank which should take you 350 miles or therabouts?
Customer: replied 2 years ago.
I have already answered you, I have spend considerable amount of money following your instruction and it didn't work. I want my money back and I don't want to hear from you anymore I am very unhappy. You promised if I am unhappy or dissatisfied with the result you give my money back. I am expecting the refund by return. Thanks George
Expert:  Matt replied 2 years ago.
understood George just follow the information here to process it