Hi,

I've a 190 SE-L diesel estate. I notice even after very sedate drives that the engine fan stays on for around 5 minutes after parking up and its quite noisy. Its not been driven hard and its not a particularly hot day. anyone elses do the same?

That'll happen when your DPF is trying to regenerate and you interrupt it. The fan kicks in because of the extreme temperatures involved, to stop the whole thing going up in flames... Take it for a long run so it empties properly, and it should stop.

It's a DPF regeneration. It needs to burn off the soot that has accumulated in the filter and it needs a lot of heat to do that. Your sedate driving probably isn't bringing temperature up fast enough to complete the process during the journey so when you stop there's still a lot of heat which is why the fan continues at full speed after you switch off. Give the car a good run - it's what it wants (and needs).

Diesels don't like sedate or short, one of the reasons I went back to petrol.

@Skodarog

when it starting high spin?

if minute after start engine then it can be high pressure in the system

http://www.briskoda.net/forums/topic/410523-rattles-vibrations-mediocre-handling-questionable-paintwork-and-other-general-negativity/#entry4707765

duplicate

Edited 13 September, 20169 yr by skodarog

That'll happen when your DPF is trying to regenerate and you interrupt it. The fan kicks in because of the extreme temperatures involved, to stop the whole thing going up in flames... Take it for a long run so it empties properly, and it should stop.

 

 

It's a DPF regeneration. It needs to burn off the soot that has accumulated in the filter and it needs a lot of heat to do that. Your sedate driving probably isn't bringing temperature up fast enough to complete the process during the journey so when you stop there's still a lot of heat which is why the fan continues at full speed after you switch off. Give the car a good run - it's what it wants (and needs).

Diesels don't like sedate or short, one of the reasons I went back to petrol.

 

thanks for the reply. i'll take it for a spin and give it the beans. i've done around 4000 miles in it since the end of July with holidays etc, so bit surprised to hear that. with other cars i always used to rag them within an inch of its life as they were always high powered petrol turbos and a heavy old XC90 which used to be trashed to get it moving, but with this i have the urge to drive more sedately apart from a few quick moments when overtaking etc - and in france had a couple of hours at very high speed fully loaded dashing back to calais after being held up in a traffic incident.

i'll take it out for a spin and report back.

@Skodarog

when it starting high spin?

if minute after start engine then it can be high pressure in the system

http://www.briskoda.net/forums/topic/410523-rattles-vibrations-mediocre-handling-questionable-paintwork-and-other-general-negativity/#entry4707765

thanks for this tip - i'll have a read up on that too.

You don't have to thrash a diesel to get the DPF to regen. You don't make the heat, the car is more than capable of doing that itself by post combustion fueling. What it does need is time to complete its cycle. A steady throttle of 2,200 rpm or so is ideal so regen can take place.

You don't have to thrash a diesel to get the DPF to regen. You don't make the heat, the car is more than capable of doing that itself by post combustion fueling. What it does need is time to complete its cycle. A steady throttle of 2,200 rpm or so is ideal so regen can take place.

okay, noted. so i drove for 60 mins and 90 mins on sunday from swindon to warwick and back - then my wife took it into town yesterday and when she came back the fan was on loud for a few minutes. would it not have tried to regenerate the DPF when i did the long run at the weekend - it was c.60mph of driving for about an hour each way? suppose next time i do a trip i might need to hold it in a lower gear to keep the RPM up over the 2200rpm.

Could just be that a regen is done on a cycle as well as the pressure sensor feedback etc. Might not have been required when you were running it.