So, I'm noticing a fan that runs on after the engine is switched off after my 10 minute drive home from work - it's like having a diesel all over again!!

I thought a GPF is supposed to work/be effective passively?? Seems not!

 

It must also throw tons of fuel in as I couldn't get the live MPG readout to go above ~20 when driving steady.

So, started a journey (~250 miles) and the MPG was woeful for approx half an hour, and then it suddenly shot up

much to my relief.

 

Happy bunny in the end, arrived at destination with an average 51.5 MPG (computer readout), this was travelling

at between 70 and 80MPH and with the air-con running as it was scorchio outside.

 

So, I'm guessing the GPF doesn't like successive short journeys, or my car is knackered! 🙂

 

Engine has to be warmed up before it becomes economical. 

I'm intrigued... What cars have this gpf?  

2 minutes ago, Alex-W said:

I'm intrigued... What cars have this gpf?  

All modern petrol engined cars are being fitted with them and usually results in a small drop in power between 4-8bhp.Mandatory equipment to get through the tough WLTP fuel consumption/emissions testing that replaced the old NEDC testing.

Sorry, let me be more specific.

Which Octavias have them, which engines from which years?

I'm assuming it's 2018 onwards?

My 19 plate 245 Tsi has a GPF ( registered 01/03/19 ). Euro 6 engine I believe 

 

 

 

Edited 10 July, 20196 yr by Auric Goldfinger

13 minutes ago, Alex-W said:

Sorry, let me be more specific.

Which Octavias have them, which engines from which years?

I'm assuming it's 2018 onwards?

 

Generally introduced summer 2018, so MY19 cars onwards

 

Has anyone else had the fan running after switching the engine off, is it common?

 

As for getting it up to temperature I didn't think this applied to petrol engines, only diesels as they take forever.

4 hours ago, ItalianJob said:

So, I'm noticing a fan that runs on after the engine is switched off after my 10 minute drive home from work - it's like having a diesel all over again!!

I thought a GPF is supposed to work/be effective passively?? Seems not!

I

 

AFAIK a re-gen can only happen when the engine is running - I had a diesel Scout and when that was doing a re-gen the tickover speed increased. I haven't noticed that happening with my new car (2.0tsi 190). Nor have I noticed the fan running after switching off, but I have known many cars do that over the years, which of course is to keep cooling the engine. Maybe that happens after a short journey when re-gen has been taking place and there's more heat in the system. I understand the re-gen happens on deceleration when more oxygen is drawn in to increase the temperature.

I'm not even sure where this cooling fan is, it's not the radiator fan that runs but something beneath/behind the engine. 

18 hours ago, ItalianJob said:

It must also throw tons of fuel in as I couldn't get the live MPG readout to go above ~20 when driving steady.

So, started a journey (~250 miles) and the MPG was woeful for approx half an hour, and then it suddenly shot up

much to my relief.

 

Happy bunny in the end, arrived at destination with an average 51.5 MPG (computer readout), this was travelling

at between 70 and 80MPH and with the air-con running as it was scorchio outside.

 

So, I'm guessing the GPF doesn't like successive short journeys, or my car is knackered! 🙂

 

 

I don't understand. Woeful MPG (above 20?) for half an hour and 51.5mpg overall consumption between 70 - 80mph?  That means for the remaining 2.5hrs or whatever you must have been achieving unbelievable MPG to reach an average of 51mpg.

 

As ever, it's just crazy for folk to talk about mpg over a short distance as there are so many factors that can affect it. Come back after 1000 miles and say what the average mpg is...  you'll find DPF, GPF or whatever else tech they introduce in reality makes no difference at all, or if it does, the difference is so small you'd need precise equipment to measure it.

 

To be honest, whether it be diesel or petrol, no engine likes successive short journeys.

 

 

Edited 11 July, 20196 yr by Guest

1 hour ago, Scot5 said:

 

I don't understand. Woeful MPG (above 20?) for half an hour and 51.5mpg overall consumption between 70 - 80mph?  That means for the remaining 2.5hrs or whatever you must have been achieving unbelievable MPG to reach an average of 51mpg.

 

As ever, it's just crazy for folk to talk about mpg over a short distance as there are so many factors that can affect it. Come back after 1000 miles and say what the average mpg is...  you'll find DPF, GPF or whatever else tech they introduce in reality makes no difference at all, or if it does, the difference is so small you'd need precise equipment to measure it.

 

To be honest, whether it be diesel or petrol, no engine likes successive short journeys.

 

 

 

So, to help you understand as I've probably explained everything badly...

For a couple of consecutive days my 10 minute journey to work has achieved an average -from start- of 20MPG, yes this is woeful as it's always

around 34MPG minimum.

On my 250 mile journey a couple of days ago, for roughly half an hour from start it was still at around 20MPG and then it reverted to 'normal'.

This then averaged out at ~51MPG at the end of the journey.

My long term average is something like 37MPG.

 

So, my main questions/query/assumption is that the GPF is doing what a DPF does and use a lot of fuel when it is active. And I didn't

realise petrol engines do this (or at least mine does), I though it was only diesels that needed that excessive fuelling/heat to burn

off the soot. This is something I've only recently noticed with my car.

 

 

 

1 hour ago, ItalianJob said:

 

So, to help you understand as I've probably explained everything badly...

For a couple of consecutive days my 10 minute journey to work has achieved an average -from start- of 20MPG, yes this is woeful as it's always

around 34MPG minimum.

On my 250 mile journey a couple of days ago, for roughly half an hour from start it was still at around 20MPG and then it reverted to 'normal'.

This then averaged out at ~51MPG at the end of the journey.

My long term average is something like 37MPG.

 

So, my main questions/query/assumption is that the GPF is doing what a DPF does and use a lot of fuel when it is active. And I didn't

realise petrol engines do this (or at least mine does), I though it was only diesels that needed that excessive fuelling/heat to burn

off the soot. This is something I've only recently noticed with my car.

 

 

 

 

 

I doubt many people know for sure but VW initially said exhaust temps were high enough on petrol models to do a regen without additional fuel.

 

Although there maybe some cases like your 10 minute journey where sufficient temperature is not achieved.

 

In 10 minutes of slow speed, light throttle, stop start even a petrol is going to struggle to get sufficient temperature built up.

3 hours ago, ItalianJob said:

I'm not even sure where this cooling fan is, it's not the radiator fan that runs but something beneath/behind the engine. 

 

Maybe you are hearing the electric coolant run on pump. It pumps for around a minute or more after engine shut down mainly to cool the turbo bearing.

 

Gpfs are integrated with the CAT on these engines I believe. They get up to operating temperature very quickly, usually less than a mile or so in summer.

It's definitely a (powerful) fan blowing upwards. Not sure quite what area it's supposed to be cooling.

3 minutes ago, ItalianJob said:

It's definitely a (powerful) fan blowing upwards. Not sure quite what area it's supposed to be cooling.

 

 

On the Diesel the fans continue to run if the car is turned off during a regen to maintain under bonnet temperatures to an acceptable level due to the artificially hot DPF and exhaust components that a regen produces.

My 245 with GPF is currently being very annoying. When driving or stationary there is a droning noise like a fan or pump running continually. You can hear it over the blowers and the engine. This coupled with 2 or 3 other problems is starting to make me hate this car more and more!

I have also noticed that a fan or something that sounds lika a fan is running for a couple of minutes after turning ignition off on my Octavia 2,0 TSI 190.
But only at warm temperature outside and after engine is at working temperature.  
 

44 minutes ago, ExSEAT said:

My 245 with GPF is currently being very annoying. When driving or stationary there is a droning noise like a fan or pump running continually. You can hear it over the blowers and the engine. This coupled with 2 or 3 other problems is starting to make me hate this car more and more!

 

Does it do it at idle?

 

The 1.6TDi suffers from something similar as soon as the revs get to 1000rpm. Some are worse than others, mine was quite bad,

53 minutes ago, logiclee said:

 

Does it do it at idle?

 

The 1.6TDi suffers from something similar as soon as the revs get to 1000rpm. Some are worse than others, mine was quite bad,

Seems to do it all the time, i'll keep an eye on the revs. Does it when stop start kicks in too. The oil was at 104 when I waa driving home then, its about 17 degrees outside so not exactly tropical and I was doing 30mph steady. Will double check the oil level once things have cooled down lol. Very annoying though, not been my best week or so with this car so its just pushed my buttons!

21 minutes ago, ExSEAT said:

Seems to do it all the time, i'll keep an eye on the revs. Does it when stop start kicks in too. The oil was at 104 when I waa driving home then, its about 17 degrees outside so not exactly tropical and I was doing 30mph steady. Will double check the oil level once things have cooled down lol. Very annoying though, not been my best week or so with this car so its just pushed my buttons!

Although I have no GPF my oil temp usually reaches 103/104C on my 26 mile mainly motorway commute even though ambient temps have been between 18C and 25C in the last week.

17 minutes ago, shyVRS245 said:

Although I have no GPF my oil temp usually reaches 103/104C on my 26 mile mainly motorway commute even though ambient temps have been between 18C and 25C in the last week.

Thanks for the info! Saves me some bother!

7 minutes ago, ExSEAT said:

Thanks for the info! Saves me some bother!

Not used a drop of oil either in the last 6 months/4,800 miles so don't worry.

59 minutes ago, shyVRS245 said:

Not used a drop of oil either in the last 6 months/4,800 miles so don't worry.

My 220 would use a full lot of oil in nearly 12 months or 6k miles

I didn,t think petrol gpf did regens as it's not necessary. The M4 doesn't. They  clean themselves efficiently while driving. BMW added 0.1 bar of boost to restore power to spec. They said the difference was minimal and surprised them especially compared to diesel. So doubt losses are are more than a hp or so on VRS. 

 

Many reasons a fan could be running, why is it a problem, ignore it and rest assured it's doing its job. 

 

My VRS oil temp has always been a bit high around 105 to 110 Deg normal driving. That is around 10 - 15 Deg hotter than our other cars. Guess the oil coolers just ain't very good.