Author Topic: Car Problems!!  (Read 51486 times)

Minder

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Re: Car Problems!!
« Reply #510 on: April 19, 2018, 12:10:45 PM »

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 ?
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tyrone girl

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Re: Car Problems!!
« Reply #511 on: April 19, 2018, 12:42:03 PM »
Im doing about 7/8 miles to work. But lots of other short journeys. 3/4 mile here and there.

Would do more at the weekends. Will start to take it down the motorway at least once a month and if keep getting it serviced every 12k or so then will ask them to put that stuff in.

Cheers

Owen Brannigan

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Re: Car Problems!!
« Reply #512 on: April 19, 2018, 07:33:21 PM »
Thanks everyone. It isnt happening every time but then im mostly doing short journeys. Few miles here and there. Have never had a burning smell from it, no smell at all.

Came up on the dash saying it needs serviced. Seems to have been serviced about 12000 miles ago so im going to book it in somewhere within the next few weeks.

If im only doing short journeys how often should i be doing a 70 mph run down the motorway?

A simple way is to drive for about 5/6 miles at high revs by going 40+ while in 4th or 5th gear.  This create enough heat to burn out the soot.

Probably the worse type of driving for a modern diesel is the 45 to 50 mph or slower trains along most A road behind slower moving lorries or even tractors where there is no real drag on a diesel and it reverts to low revs.  At times like this it is well worth changing down to bring up the revs for about 5/10 minutes to create a burn out.

Need to remember that this burn out during a regeneration cycle does create 'ash' which will eventually mean that a 5/6 year old diesel engine of the modern variety with these complex DPFs will need the ash removed even if the soot filter has been regenerated often.

Owen Brannigan

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Re: Car Problems!!
« Reply #513 on: April 19, 2018, 08:13:49 PM »

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

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Re: Car Problems!!
« Reply #514 on: April 20, 2018, 12:36:59 AM »

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

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Re: Car Problems!!
« Reply #515 on: April 20, 2018, 12:51:45 AM »
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?
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tyrone girl

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Re: Car Problems!!
« Reply #516 on: April 20, 2018, 09:26:48 AM »
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

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Re: Car Problems!!
« Reply #517 on: April 20, 2018, 09:53:55 AM »
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

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Re: Car Problems!!
« Reply #518 on: April 20, 2018, 10:03:32 AM »
Anyone any experience of DPF cleaning services, Terraclean etc. Is it worth the bother?

Denn Forever

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Re: Car Problems!!
« Reply #519 on: April 20, 2018, 11:48:09 AM »
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.
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offtheground

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Re: Car Problems!!
« Reply #520 on: April 20, 2018, 11:56:32 AM »
GJL - could you recommend a brand of Diesel additive?

Itchy

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Re: Car Problems!!
« Reply #521 on: April 20, 2018, 01:07:12 PM »
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

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Re: Car Problems!!
« Reply #522 on: April 20, 2018, 01:09:59 PM »
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

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Re: Car Problems!!
« Reply #523 on: April 20, 2018, 07:38:35 PM »
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.
« Last Edit: April 20, 2018, 07:45:50 PM by Owen Brannigan »

Owen Brannigan

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Re: Car Problems!!
« Reply #524 on: April 20, 2018, 07:47:15 PM »
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.