passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION

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Mon 10 Dec 2012 15:07
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - TheDervDoctor

Hey i own a passat 2.0 20v petrol sport 52reg i have owned this for about a year now and the fuel consumption is getting considerably worse. I used to get roughly 100 miles to £20 which is about 400 miles to a full tank which is £80 which i was quite happy with. Now i am lucky if i get 50 miles to £20 and 250 miles max to a full tank just wondering if anyone else had come across this or any one know how to fix this issue.

thanks in advance.

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Mon 10 Dec 2012 15:25
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - Collos25

If your fuel consumption doubles then you have a serious fault(s) I suggest you have it looked sooner then later because if the fuel is diluting the engine oil you are in for a very big bang.

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Mon 10 Dec 2012 15:57
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - unthrottled

It's difficult to accurately measure fuel consumption by putting £20 in the tank. Put bluntly, when you put fixed amounts of fuel in the tank, it's normally because you're short of money and there's a tendency to go further into the red each time before buying more fuel. The extra miles you squeeze out of the old top-up are of course borrowed from the next one, so you think that your economy has taken a precipitous dive when in reality nothing has happened!

The colder weather won't help. At that age of car, any fuelling issue should be self diagnosing (unless someone has removed the EML...). Check that your brakes aren't binding etc.

You can try reading spark plugs, but usually the engine management will detect a fault before you do.

Edited by unthrottled on 10/12/2012 at 15:57

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Mon 10 Dec 2012 16:49
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - TheDervDoctor

hey just got the message thanks for the reply how i was working it out is on the fuel guage £20 moves the guage 2 of the little markers on the guage so i was working out how many miles i got between them and it really has got worse also the car is using about 1 litre of oil every 600miles which to me is alot but it does say in the hand book that it can use upto that but am not sure if this has something to do with it also i have diognostics and have pluged it in and there are no faults so am not to sure its confusing me alot.

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Mon 10 Dec 2012 16:56
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - unthrottled

That's pretty awful oil consumption. Is there oil being forced out of the dipstick tube? You might have a malfunctioning PCV valve or a collapsed breather hose which means that the engine isn't venting properly. That can affect engine performance and cause high oil consumption. There should be a hose that runs from the top of the engine to the intake air pipe just past the air filter housing. If you disconnect this hose whilst the engine is idling, there should be a very light draw into the engine. If gases are puffing out, then your PCV isn't working.

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Mon 10 Dec 2012 17:53
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - TheDervDoctor

hey just had a look at that and yeah there is only a slight draw theres no gases puffing out or nothing like that there is quite abit of oil in the little pipe that goes from the air intake to that valve thing i have also had a quick check of the breathers and they all seem fine so i honestly dont know also another thing i noticed sometimes not all the time is that the brake are as if there is no servo then all of a sudden work as normall not to sure on that eather dont know if that could be rleated to vacume somewhere along the line. also i dont know what made me try this but the other day i put my foot to the floor and the car pulled then i put my left foot on the brake basically "left foot braking" whilst i kept my accelerator to the floor then i let of the brake and the car basically had no power for about 5-6 seconds then picked back up again dont know if thats normall eather as i have never known a car to do that eather.

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Mon 10 Dec 2012 19:17
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - Collos25

I really do not think you should be driving the car given the faults you have related.

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Mon 10 Dec 2012 21:29
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - unthrottled

A lot of cars cut power if you press the brake and can be a bit bolshie afterwards, so I wouldn't worry about that. Vacuum leaks normally lead to elevated idle (and often hunting). Do you have any of these symptoms. If you've got a problem with your servo, is it possible that your brakes aren't fully releasing from the discs? Do the brakes get very hot after normal driving?

Anyone else?

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Tue 11 Dec 2012 07:58
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - TheDervDoctor

yeah i wasent to sure on that one and as far as i can see the brakes are fine if i jack it up all the wheels spin freely and the wheels arent hot there just normall temprature from normall braking so i have absoloutly no idea its got me puzzled where could i buy a pcv valve from as i have tried ebay and google for someone or somewhere selling them but i havent any luck might have to be the dealer. because if there cheap i could try it to see if it makes any diffrence.

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Tue 11 Dec 2012 11:00
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - pd

Get it code read,. It could be something as simple as a duff temperature sensor (very common on these engines) leading to the engine thinking it is cold all the time.

The oil cnsumption is certianly on the high side - it could be related or it might be a different issue.

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Tue 11 Dec 2012 12:41
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - TheDervDoctor

i have diognostics my self and i have pluged it in but there are no fault codes could the engine temp sensor like you say be duff put not duff enough to bring a code up and i was thinking maybe airflow sensor might be duff but not enough for a code what do you think.

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Tue 11 Dec 2012 12:46
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - unthrottled

Why not pull the spark plugs and see what colour they are? The tips should be light tan. If they are dark/and or soot covered that's a sign of a rich mixture.

Seriously faulty MAFs tend to cause driveability problems, stumbling/hesitation etc.

Edit: While you're at it, it is as well to make sure that the thermostat is fully closed when the engine is warming up. Even a small gap will significantly increase engine warm up time and will have a negative effect on fuel economy.

Check the simple things first.

Edited by unthrottled on 11/12/2012 at 12:49

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Wed 12 Dec 2012 17:44
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - TheDervDoctor

i will check the plugs tommorow and tell you the colour and i might just change the thermostat as there not expensive eather thanks for the reply al get back to you tommorow.

and in reply to the last message it is OBD2 Autel code reader i have also used vag com and there are no codes

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Tue 11 Dec 2012 13:59
passat 2.0 20v petrol sport - PASSAT 2.0 20V PETROL SPORT BAD FUEL CONSUMPTION - Collos25

If your using a standard OB11 then you will not get the full code readout you need the specific VAG VW Passat reader program.

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