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[TheBoy]

Only test on a diesel car is an absolutely fickin brutal smoke test. Most diesels don't get to 4000rpm in daily driving, then the MOT man tries to kill your car.

The Zafira somehow always passed the smoke test. Probably because it wouldn't rev to 4k rpm

[Kevin Wood]

Only test on a diesel car is an absolutely fickin brutal smoke test. Most diesels don't get to 4000rpm in daily driving, then the MOT man tries to kill your car.

Your going t wrong MOT station if they rev it that hard.....I know they should tho'

My MOT garage just gives a quick blip on the throttle and leaves it at that 

I thought the test was all system monitored now?

Damn well ought to be. If it can't be held at 4,000 RPM for a few seconds without dying, then better it dies there and then than carry on chucking out soot and unburnt fuel.

[TheBoy]

About time too. There are too many tractors driving round with emissions that make your eyes water. Drive a convertible for a day and you'll understand what your pollen filter has been removing.

Yet, my pre-DPF fog monster will not have to obey these rules...  ...put probably will be the first to hit these city centre taxes, being an old soot chucker.


Gixer and I noticed on the Jag, only one bank of cylinders has a cat on it.  Upon checking the workshop manual, that is correct

[Viral_Jim]

Take it thatbit has an x pipe or similar so the gasses from both banks mix?

I suppose why bother with a second if scrubbing 50% of the gas will need current regs. Any more than that and you're only adding cost no benefit, other than that of the polar bears. 

[TD]

Only test on a diesel car is an absolutely fickin brutal smoke test. Most diesels don't get to 4000rpm in daily driving, then the MOT man tries to kill your car.

Your going t wrong MOT station if they rev it that hard.....I know they should tho'

My MOT garage just gives a quick blip on the throttle and leaves it at that 

I thought the test was all system monitored now?

Damn well ought to be. If it can't be held at 4,000 RPM for a few seconds without dying, then better it dies there and then than carry on chucking out soot and unburnt fuel.

Nope...MOT blokey can click on various messages disregarding messages about engine/exhaust temp....and then just let it idle after a quick blip on the throttle when it does the smoke test.....or did when mine was last tested 

I can see the point about soot Kevin, but a petrol can chuck out unburnt fuel as well .... whats the difference between diesel and petrol unburnt fuel I don't know.... 

[steve6367]

Only test on a diesel car is an absolutely fickin brutal smoke test. Most diesels don't get to 4000rpm in daily driving, then the MOT man tries to kill your car.

Your going t wrong MOT station if they rev it that hard.....I know they should tho'

My MOT garage just gives a quick blip on the throttle and leaves it at that 

I thought the test was all system monitored now?

Damn well ought to be. If it can't be held at 4,000 RPM for a few seconds without dying, then better it dies there and then than carry on chucking out soot and unburnt fuel.

Nope...MOT blokey can click on various messages disregarding messages about engine/exhaust temp....and then just let it idle after a quick blip on the throttle when it does the smoke test.....or did when mine was last tested 

I can see the point about soot Kevin, but a petrol can chuck out unburnt fuel as well .... whats the difference between diesel and petrol unburnt fuel I don't know.... 

If it does it will fair the emissions test, that is the difference.

[Doctor Gollum]

Could be a good reason to lpg a car then... replace the cats with a straight though pipes and remove the rev limiter

Cheap fuel costs are a happy bonus...

[Kevin Wood]

If it does it will fair the emissions test, that is the difference.

Exactly. The petrol emissions test is actually designed to detect common faults that might cause the original emissions criteria not to be met.

The diseasel test is designed to ensure the guy behind can still see where he's going.

[Nick W]

If it does it will fair the emissions test, that is the difference.

Exactly. The petrol emissions test is actually designed to detect common faults that might cause the original emissions criteria not to be met.

The diseasel test is designed to ensure the guy behind can still see where he's going.

The petrol test highlights faults that tend to be fixable.
The diesel test presents faults that you could spend £000's chasing and still not fix because they're characteristic of diesel engines.

[Webby the Bear]

Only test on a diesel car is an absolutely fickin brutal smoke test. Most diesels don't get to 4000rpm in daily driving, then the MOT man tries to kill your car.

Your going t wrong MOT station if they rev it that hard.....I know they should tho'

My MOT garage just gives a quick blip on the throttle and leaves it at that 

I thought the test was all system monitored now?

Damn well ought to be. If it can't be held at 4,000 RPM for a few seconds without dying, then better it dies there and then than carry on chucking out soot and unburnt fuel.

Nope...MOT blokey can click on various messages disregarding messages about engine/exhaust temp....and then just let it idle after a quick blip on the throttle when it does the smoke test.....or did when mine was last tested 

I can see the point about soot Kevin, but a petrol can chuck out unburnt fuel as well .... whats the difference between diesel and petrol unburnt fuel I don't know.... 

I'd say that because tractors chuck out unburned fuel constantly. If a petrol does it's because there's an issue.

Diesels in my opinion are awful. I hate the smell. I hate the sound. I find it funny when people who buy them trying to save money end up needing turbos, DPFs, EGRs, injectors, etc.

This all happens because diesel doesn't burn well and these issues are all because of this.

I love my petrol guzzling omega 😂😂😂

[TD]

Only test on a diesel car is an absolutely fickin brutal smoke test. Most diesels don't get to 4000rpm in daily driving, then the MOT man tries to kill your car.

Your going t wrong MOT station if they rev it that hard.....I know they should tho'

My MOT garage just gives a quick blip on the throttle and leaves it at that 

I thought the test was all system monitored now?

Damn well ought to be. If it can't be held at 4,000 RPM for a few seconds without dying, then better it dies there and then than carry on chucking out soot and unburnt fuel.

Nope...MOT blokey can click on various messages disregarding messages about engine/exhaust temp....and then just let it idle after a quick blip on the throttle when it does the smoke test.....or did when mine was last tested 

I can see the point about soot Kevin, but a petrol can chuck out unburnt fuel as well .... whats the difference between diesel and petrol unburnt fuel I don't know.... 

If it does it will fair the emissions test, that is the difference.

Sorry, on the environment I meant.....A petrol could fail the emissions test on one day of the year...then scrape through the test and go back to chucking out unburnt fuel for the rest of the year.....

[Kevin Wood]

Only test on a diesel car is an absolutely fickin brutal smoke test. Most diesels don't get to 4000rpm in daily driving, then the MOT man tries to kill your car.

Your going t wrong MOT station if they rev it that hard.....I know they should tho'

My MOT garage just gives a quick blip on the throttle and leaves it at that 

I thought the test was all system monitored now?

Damn well ought to be. If it can't be held at 4,000 RPM for a few seconds without dying, then better it dies there and then than carry on chucking out soot and unburnt fuel.

Nope...MOT blokey can click on various messages disregarding messages about engine/exhaust temp....and then just let it idle after a quick blip on the throttle when it does the smoke test.....or did when mine was last tested 

I can see the point about soot Kevin, but a petrol can chuck out unburnt fuel as well .... whats the difference between diesel and petrol unburnt fuel I don't know.... 

If it does it will fair the emissions test, that is the difference.

Sorry, on the environment I meant.....A petrol could fail the emissions test on one day of the year...then scrape through the test and go back to chucking out unburnt fuel for the rest of the year.....

Not necessarily. A petrol car in good condition will pass the test every day of the year with a massive margin. If a car is borderline, then the test is doing what it should and weeding out faulty cars. The fact that some faults are gradual in their nature (i.e. the degrading of a cat) mean that there will be a few years where it will "scrape through" but remember that an MOT test is carried out in the most challenging conditions - with the cat relatively cool because the engine cannot be driven under load. A car that has "scraped through" will probably still be compliant when under load on the road because the cat will be much hotter.

Contrast that with the diesel test which looks for density of smoke only during a brief acceleration of the engine. It doesn't matter what's in the exhaust as long as the density is within limits. I suspect a lot of older diesels have injectors that are delivering a dribble of fuel instead of atomising it. They still pass but with all manner of sh1te coming out of the exhaust. About time they were checked for Hydrocarbon emissions.

[Migv6 le Frog Fan]

My "diesel" car passes the smoke test as long as it is actually running on diesel and " not making the workshop smell like a farkin chip shop". Wrong smell is  an immediate fail. 

[Marks DTM Calib]

Remember also that if a petrol car is chucking out un-burnt fuel then the cat will be dead pretty quickly, his will then fail the test even of the Lambda figure is met.

Interestingly, I got a print out two weeks ago when the bus passed its MOT which showed the particulate levels at differing engine revs which was a surprise (it passed easily as it does have a fitted and working DPF - 185k miles and no issues)

[tunnie]

Remember also that if a petrol car is chucking out un-burnt fuel then the cat will be dead pretty quickly, his will then fail the test even of the Lambda figure is met.

Interestingly, I got a print out two weeks ago when the bus passed its MOT which showed the particulate levels at differing engine revs which was a surprise (it passed easily as it does have a fitted and working DPF - 185k miles and no issues)

At these kind of miles, do you begin to have issues with ash? As I understand it the soot is burned off in the re-gen process, leaving just ash.

VAGCOM tells me there is 34g of ash in my DPF and it can hold 75g, currently on 83k miles. But suggests 160k+ it could be approaching full, at that point can you remove the DPF to get rid of the cash?