2008 1.4i polo 9n heavy on petrol

Neeven
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2008 1.4i polo 9n heavy on petrol

Post by Neeven »

Good day, I have 2008 polo trendline 1.4i,currently doing 164 000 kms. The car is currently doing 11kms/litre. I have done the service, ran 3 diagnostics on the car (including Volkswagen), and no one seems to pick up any faults with regards to why the car is so heavy on fuel. I have also gotten the throttle body cleaned, removed the catalytic converter aswell but it still hasn't helped with improving fuel economy. I drive between 100km-120km at most, I'm also stuck in traffic for roughly 10 minutes in a day aswell so I'm not sure if that's the reason for the heavy consumption. Also the guy I bought the guy from did tell me that he had changed the water pump on the car, but he didn't put a genuine part but it seems to be working fine.

Could it be water pump that's causing the car to be heavy on petrol?

Any advice to solve this issue will be appreciated, thank you.

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EX-DOHCTOR
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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

Waterpump runs off the cambelt bud, won't have any impact on fuel economy what so ever.

I have to ask, why have you done all this elaborate stuff trying to diagnose this issue?
Sounds like the mechanics have been milking you doing a lot of pointless unnecessary things.

Do you have any of the results from the diagnostics that you could post here on the forum?

Has the basics been checked first?

For example, have they checked or changed the engine coolant sensor?
Checked engine timing?
Any electrical issues with the car?
Is the lambda plug in and seated properly on the exhaust where they removed the cat?
Is the knock sensor present and plugged in firmly?
Sparkplugs good?
Sparkplug leads good?

Also, where are you based?
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
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Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

EX-DOHCTOR wrote:Waterpump runs off the cambelt bud, won't have any impact on fuel economy what so ever.

I have to ask, why have you done all this elaborate stuff trying to diagnose this issue?
Sounds like the mechanics have been milking you doing a lot of pointless unnecessary things.

Do you have any of the results from the diagnostics that you could post here on the forum?

Has the basics been checked first?

For example, have they checked or changed the engine coolant sensor?
Checked engine timing?
Any electrical issues with the car?
Is the lambda plug in and seated properly on the exhaust where they removed the cat?
Is the knock sensor present and plugged in firmly?
Sparkplugs good?
Sparkplug leads good?

Also, where are you based?
The reason I have done the above stuff, was because I was getting advice from different guys trying to see if they maybe know the solution to this problem only to find out I've been wasting my time and money as nothing have helped.

I've never checked or had anyone check the sensors on the car however I did the service last month so spark plugs are new yet still experiencing the heavy petrol consumption.

Perhaps I need to get the sensors checked out as you pointed out that would be the best place to start.

I'm from Durban



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JCTPUBLISHERS
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Re: 2008 1.4i polo 9n heavy on petrol

Post by JCTPUBLISHERS »

Do a diagnostic first?
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

JCTPUBLISHERS wrote:Do a diagnostic first?
I've gotten a diagnostics done by 3 different guys, including Volkswagen. The guy there said that 11 kms is good apparently Image. But for a 1.4i it seems like that's quite heavy

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EX-DOHCTOR
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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

Ok, so it seems you’ve been getting really duff advice from people who don’t know what they are talking about. We call this school fees.

Go to the engine now, pull out a spark plug and look at the electrode, is it heavily caked in thick black soot?

It is wet with fuel?
When you start the car, is there heavy black smoke coming from the exhaust?

When you drive the car, is the temperature gauge reading consistently once the engine has warmed up? Or does the gauge randomly swing when driving and idling?

Did this issue start recently or have you only recently got this car?

My 2004 1.4i 9n averaged 8l/100km consistently for years.
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
Instagram: https://www.instagram.com/projectkirschwasser/

Racing is meant for the RACE track - deal with it...
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

I will check the spark plugs in a few minutes and also send a Pic.

The car doesn't have a black smoke when I start it, however this morning when I started it, the temperature Guage was flashing and beeping. So when I switched it off and started it again, it stopped. Not sure if that has something to do with the fuel consumption.

Whilst driving the heat Guage is either quarter way or half way and it increases and decreases between the quarter and half way mark. Is this normal for a car to do?

I've had this car for almost a year now and the petrol issue has been a problem from that time



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Greenz
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Greenz »

Sounds like a water temp sensor.
2010 ST225 - 238kw 439nm
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

Greenz wrote:Sounds like a water temp sensor.
Okay thank you, I will have that checked.

Just to find out, is the heat Guage supposed to stay half way or it is supposed to go up and down( from 0°c to 90°c )whilst driving?

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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

Neeven wrote: Sat Sep 11, 2021 10:28 am I will check the spark plugs in a few minutes and also send a Pic.

The car doesn't have a black smoke when I start it, however this morning when I started it, the temperature Guage was flashing and beeping. So when I switched it off and started it again, it stopped. Not sure if that has something to do with the fuel consumption.

Whilst driving the heat Guage is either quarter way or half way and it increases and decreases between the quarter and half way mark. Is this normal for a car to do?

I've had this car for almost a year now and the petrol issue has been a problem from that time

Image

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Temperature gauge measures the water and coolant temperature in circulation in the water cooling system. Like the water pump... nothing to do with fuel consumption at all.

The temperature gauge is not meant to swing around, that sounds like a faulty coolant temp sensor. Once the car has warmed up it should, generally stick to the 90' position, unless the car is overheating, obviously.

The sensor replacement is like a 5 minute job to replace. Nothing elaborate or fancy about it, you remove the u-clip, pull out the sensor, replace with new sensor and stick the u-clip back in. You should do it when the car is cold though. You might lose a little coolant and water when you remove the old sensor.

Are you using the correct coolant (VW G12 - pink in color) in the correct ratio in this car?
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

Neeven wrote: Sat Sep 11, 2021 11:43 am
Greenz wrote:Sounds like a water temp sensor.
Okay thank you, I will have that checked.

Just to find out, is the heat Guage supposed to stay half way or it is supposed to go up and down( from 0°c to 90°c )whilst driving?

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Nothing to check, just replace it. You won't have a means of testing it.

Gauge needle is not supposed to swing all over the place. It should stay roughly in the 90'C/middle position.
Last edited by EX-DOHCTOR on Sat Sep 11, 2021 1:46 pm, edited 1 time in total.
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
Instagram: https://www.instagram.com/projectkirschwasser/

Racing is meant for the RACE track - deal with it...
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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

These are the bits you need:

Image
Image

Located here:
Image
Image

Go grip one from you local Goldwagen or even VW Dealer, they're not expensive.

Change it when the car is cold, should be an instant fix once replaced.

Drive around a bit and see.
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
Instagram: https://www.instagram.com/projectkirschwasser/

Racing is meant for the RACE track - deal with it...
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

EX-DOHCTOR wrote:
Neeven wrote: Sat Sep 11, 2021 10:28 am I will check the spark plugs in a few minutes and also send a Pic.

The car doesn't have a black smoke when I start it, however this morning when I started it, the temperature Guage was flashing and beeping. So when I switched it off and started it again, it stopped. Not sure if that has something to do with the fuel consumption.

Whilst driving the heat Guage is either quarter way or half way and it increases and decreases between the quarter and half way mark. Is this normal for a car to do?

I've had this car for almost a year now and the petrol issue has been a problem from that time

Image

Sent from my MAR-LX2 using Tapatalk
Temperature gauge measures the water and coolant temperature in circulation in the water cooling system. Like the water pump... nothing to do with fuel consumption at all.

The temperature gauge is not meant to swing around, that sounds like a faulty coolant temp sensor. Once the car has warmed up it should, generally stick to the 90' position, unless the car is overheating, obviously.

The sensor replacement is like a 5 minute job to replace. Nothing elaborate or fancy about it, you remove the u-clip, pull out the sensor, replace with new sensor and stick the u-clip back in. You should do it when the car is cold though. You might lose a little coolant and water when you remove the old sensor.

Are you using the correct coolant (VW G12 - pink in color) in the correct ratio in this car?
Okay so I've checked the spark plug and it's looking like new

I've just bought a sensor from goldwagen and got it fitted, I'll take the car for a long drive tomorrow and see if there's any issues.

My temperature Guage seems to always go up and down and doesn't stay constant. I'll see by tomorrow if the Guage is still moving around or if the new sensor has helped.

I'm not quite sure about the coolant because I haven't topped it up,but it is pinkish in colour.

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Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

EX-DOHCTOR wrote:These are the bits you need:

Image
Image

Located here:
Image
Image

Go grip one from you local Goldwagen or even VW Dealer, they're not expensive.

Change it when the car is cold, should be an instant fix once replaced.

Drive around a bit and see.
Thank you, this has helped me. I will update you if the sensor has helped or if the problem persistsImage. Fingers crossed

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Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

The temperature sensor that came off my carImageImage

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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

Interesting, I don't remember mine having threads but mine was an older model 9N so that's possible why.

Has the temperature gauge needle stopped swinging around?
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
Instagram: https://www.instagram.com/projectkirschwasser/

Racing is meant for the RACE track - deal with it...
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

It's the one that fits on the radiator right? A friend told me what I've changed is the switch to the radiator after which I've doubted if it was the correct thing.

Yesterday I've took a drive to chatsworth so I was observing the heat Guage and noticed it's more often on the quarter mark than the half way mark

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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

Sounds like you might’ve changed the radiator fan switch.

The coolant temp sensor sits in a pipe above the radiator as in the photos. Shouldn’t be any threads from what I remember.
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
Instagram: https://www.instagram.com/projectkirschwasser/

Racing is meant for the RACE track - deal with it...
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

Yes you're right, I phoned goldwagen and confirmed and I did buy the wrong part. The other guy there didn't understand and sold me the wrong thing. I will go get the correct sensor and install it today evening

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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

I figure it can't hurt to leave the new plug in place. Its one less thing to worry about.

Do you have any service history on the car from the previous owner?
Do you know if they ever changed the thermostat and housing on that car?

When you checked the spark plugs, were they all clean and free of black soot?
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
Instagram: https://www.instagram.com/projectkirschwasser/

Racing is meant for the RACE track - deal with it...
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

Unfortunately the previous owner didn't have a service history for the car, the only thing he told me was that the cars waterpump had been changed and he said that car didn't overheat or anything but the waterpump was throwing signals so he had it changed

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Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

And when I've checked the spark plugs, it was like new because I've recently changed it about a month ago

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Re: 2008 1.4i polo 9n heavy on petrol

Post by EX-DOHCTOR »

So with the mileage I am assuming (and hoping) he did the cambelt and waterpump together.

Lets see how things go after the coolant temp sensor is changed.
2014 - VW Jetta 6 - 1.6 TDi DSG
2000 - VW Golf 3.5 Cabrio - 2.0
1980 - VW MK1 GT - 1.8 Carb - https://www.vwclub.co.za/forum/viewtopi ... 1&t=153861
1971 - Mitsubishi Colt 1100F - https://www.vwclub.co.za/forum/viewtopi ... 1&t=220503
MK1 Build Register: https://www.vwclub.co.za/forum/viewtopi ... 1&t=192835
Instagram: https://www.instagram.com/projectkirschwasser/

Racing is meant for the RACE track - deal with it...
Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

After I've purchased the car, I did a full service and changed the cambelt, so I think that's okay aswell. We'll just have to see after I get the sensor

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Neeven
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Re: 2008 1.4i polo 9n heavy on petrol

Post by Neeven »

Okay so I've managed to get the correct part this time around ImageI will replace it when I get home and take it for a drive and see how it goesImage

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