Car Problems!!

[Owen Brannigan]

Anyone give me a bit of advice. Have the car about a month (it isnt new). All has seemed grand but have noticed intermittently that when i stop the car and turn it off there is like a fan noise that comes from engine as if it is cooling down or something. Its quite loud even though car is completely off. Timed it the last few times and it goes on for about 3 minutes. It isnt every time i turn it off but starting to happen a bit more often over these last 2 days.
Anyone any ideas? Im panicking that its something major

Not a mechanic like GJL but same thing happens with my (diesel) car and my husband's as well.

It is the DPF regenerating to burn off the carbon deposits in the filter. Shouldn't allow this to happen too often without dipping your engine oil to make sure it isn't rising. The deposits form if you have short journeys or at the end of a low rev or speed journey as the car doesn't carry out a regeneration cycle before you stop the engine. Diesel is dumped into the collection vessel to burn off the soot. If this occurs too often the excess diesel finds its way to engine oil and then you have bother. If you hear the noise again you will also find a burning smell. This is the bother of having a DPF and a clean Diesel engine. All very expensive to have cleaned out or replaced. Secondhand diesels of this type will become a financial mine field.

Would a long drive sort this out ? Burn out all the dirt

Yea. All modern diesel cars with a DPF benefit from a good spin out a motorway at 70mph so that the system can perform a full regeneration. You can also get an additive for the fuel that you can put in every 10000 miles or so that will help clean the whole system.

Is that what AdBlue does ?

Adblue is added to breakdown the NOx gases that so many now complain about as the major health hazard of diesels now that the latest engine standards on diesel particulates have largely removed them as a serious problem.

BTW the latest particulate problem from vehicles are the rubber particles that wear off your tyres as you drive along!

[GJL]

Anyone give me a bit of advice. Have the car about a month (it isnt new). All has seemed grand but have noticed intermittently that when i stop the car and turn it off there is like a fan noise that comes from engine as if it is cooling down or something. Its quite loud even though car is completely off. Timed it the last few times and it goes on for about 3 minutes. It isnt every time i turn it off but starting to happen a bit more often over these last 2 days.
Anyone any ideas? Im panicking that its something major

Not a mechanic like GJL but same thing happens with my (diesel) car and my husband's as well.

It is the DPF regenerating to burn off the carbon deposits in the filter. Shouldn't allow this to happen too often without dipping your engine oil to make sure it isn't rising. The deposits form if you have short journeys or at the end of a low rev or speed journey as the car doesn't carry out a regeneration cycle before you stop the engine. Diesel is dumped into the collection vessel to burn off the soot. If this occurs too often the excess diesel finds its way to engine oil and then you have bother. If you hear the noise again you will also find a burning smell. This is the bother of having a DPF and a clean Diesel engine. All very expensive to have cleaned out or replaced. Secondhand diesels of this type will become a financial mine field.

Would a long drive sort this out ? Burn out all the dirt

Yea. All modern diesel cars with a DPF benefit from a good spin out a motorway at 70mph so that the system can perform a full regeneration. You can also get an additive for the fuel that you can put in every 10000 miles or so that will help clean the whole system.

Is that what AdBlue does ?

As Owen explained AdBlue is for a slightly different purpose. I'd recommend an additive every few thousand miles as I will clean the whole system including injectors, EGR valve, DPF filter etc. Basically it de-carbons the components.

[ONeill]

Anyone give me a bit of advice. Have the car about a month (it isnt new). All has seemed grand but have noticed intermittently that when i stop the car and turn it off there is like a fan noise that comes from engine as if it is cooling down or something. Its quite loud even though car is completely off. Timed it the last few times and it goes on for about 3 minutes. It isnt every time i turn it off but starting to happen a bit more often over these last 2 days.
Anyone any ideas? Im panicking that its something major

Have you definitely turned the car off?

[tyrone girl]

If im driving an automatic how do i do the rev in lower gears as will it not just auto change to the best gear?

[Rois]

If im driving an automatic how do i do the rev in lower gears as will it not just auto change to the best gear?

Presumably you have a manual button?  I can flick onto manual and use the buttons on my steering wheel to manually change gear.

[Last Man]

Anyone any experience of DPF cleaning services, Terraclean etc. Is it worth the bother?

[Denn Forever]

If im driving an automatic how do i do the rev in lower gears as will it not just auto change to the best gear?

What do you mean "rev in lower gears?"  As you drive off and build up the revs. you'll go faster.

[offtheground]

GJL - could you recommend a brand of Diesel additive?

[Itchy]

Anyone give me a bit of advice. Have the car about a month (it isnt new). All has seemed grand but have noticed intermittently that when i stop the car and turn it off there is like a fan noise that comes from engine as if it is cooling down or something. Its quite loud even though car is completely off. Timed it the last few times and it goes on for about 3 minutes. It isnt every time i turn it off but starting to happen a bit more often over these last 2 days.
Anyone any ideas? Im panicking that its something major

Have you definitely turned the car off?

Thats normal in some models. What make is it?

[omagh_gael]

If im driving an automatic how do i do the rev in lower gears as will it not just auto change to the best gear?

What do you mean "rev in lower gears?"  As you drive off and build up the revs. you'll go faster.

Ay, but the aim is to go 50mph in say 4th gear at high revs as opposed to 50mph comfortably in 5th gear. If you can't turn off automatic you'll not be able to choose to go high speed in a lower gear than required to create the burn off effect. 

[Owen Brannigan]

If im driving an automatic how do i do the rev in lower gears as will it not just auto change to the best gear?

Actually having an automatic can be a help in burning off the soot.  An automatic with a torque converter will actually cause the engine to rev high quite often and this helps.  Mercedes C/D/S have little problems with DPF because they have torque converter auto boxes.  Another type of auto box is the CVT which is also a high revving box by nature and burns off the soot.  The final auto box is the dual clutch or DSG(VW).  It changes gear quickly and does cause the same amount of engine revving as the others so if yours is one of these as Rois says put it into manual mode and run in lower gear for 10 minutes to raise the revs and begin the regeneration cycle.

All dual clutch autos will have a manual mode as they are often considered to be semi-automatics as you can drive them through the gears but without the need for a clutch, some have paddles on the steering column.

I think the Astra will have a dual clutch semi automatic.

[Owen Brannigan]

Anyone any experience of DPF cleaning services, Terraclean etc. Is it worth the bother?

They are supposed to be good at removing the soot but I believe some ash remains and will eventually require more work to clear the filter.

[tyrone girl]

Surprise surprise im back again with another problem 

My car conked out yesterday as i was sitting at a roundabout waiting to move. Now maybe im thick but i presumed an automatic car shouldnt really conk out??

Anyway i started it again and it was grand i never thought much more about it as it was driving fine. Last night though the service soon light came on. I have been reading up that sometimes this can be an indicator of a random fault in the vauxhall astra. I then seemed to lose power and the car wouldnt go past 40 no matter how much i tried to accelerate.

Any ideas?

[Minder]

Surprise surprise im back again with another problem 

My car conked out yesterday as i was sitting at a roundabout waiting to move. Now maybe im thick but i presumed an automatic car shouldnt really conk out??

Anyway i started it again and it was grand i never thought much more about it as it was driving fine. Last night though the service soon light came on. I have been reading up that sometimes this can be an indicator of a random fault in the vauxhall astra. I then seemed to lose power and the car wouldnt go past 40 no matter how much i tried to accelerate.

Any ideas?

Have you still got your receipt ?

[Last Man]

Surprise surprise im back again with another problem 

My car conked out yesterday as i was sitting at a roundabout waiting to move. Now maybe im thick but i presumed an automatic car shouldnt really conk out??

Anyway i started it again and it was grand i never thought much more about it as it was driving fine. Last night though the service soon light came on. I have been reading up that sometimes this can be an indicator of a random fault in the vauxhall astra. I then seemed to lose power and the car wouldnt go past 40 no matter how much i tried to accelerate.

Any ideas?

Something is causing the engine to go into Limp mode, basically protecting itself from damage. Often turning it off and restarting can reset this for a while but you'd be best get a mechanic to scan the error log to get an idea what might be the root cause. If you get the error codes and post them on a vauxhall forum you might get a heads up there.