failed MOT on emissions

[JimSuperSix]

It failed last week on emissions - should be around 3 and it was over 5 on whatever scale it is they use.

The vehicle covers only about 6000 miles a year, almost all of that is commuting on A roads in traffic, so very rarely sees above 2500rpm. When driving I see no smoke at all, just a puff of black and perhaps white on startup. Even at full throttle I can see no smoke behind, unless it's dark when the headlights of a car behind show a slightly smoky trail.

Also after replacing the head I'm paranoid and drive it very gently - I think this may be the source of the MOT failure - what do you guys think?

I'm concerned that it may fail the retest and then I'm really stuck - I've put a new fuel filter on (never had one before) and filled it with Redex, put the rest of the bottle in the fuel tank, and by the retest it will have run through the whole tank while being mercilessly thrashed. It had a new air filter 6 months ago. Head is about 3 years old now (from Stevo).

Is there anything else I can do to ensure it passes the retest? I know nothing about reducing emissions on diesels (I wish it was as simple as carbs on a kitcar - twiddle 2 screws = no emissions - brilliant!)

thanks
James

[marky]

Stick a bottle of redex for DIESELS in a 1/4 of a tank and run for a while, then right before MOT make sure you take it for a good blast to clear it out. Also disconnecting the EGR will lower the emissions.
EGR pic on here http://www.hiluxsurf.co.uk/forums/sh...&highlight=egr

[The Hornet]

I've read that a dosing of Veg oil helps as well.

[JimSuperSix]

Marky - that EGR mod, can it really be done that simply?

I thought you had to take off the EGR pipe and stick a ball-bearing or a blocking plate in?

I would have thought that not recycling your exhaust gases would *increase* emissions????

[stormforce]

Marky - that EGR mod, can it really be done that simply?

I thought you had to take off the EGR pipe and stick a ball-bearing or a blocking plate in?

I would have thought that not recycling your exhaust gases would *increase* emissions????

no just bend the pipe and cable tie it tight.Run some redex thru the system and pour in several litres of veggie and away you go

[marky]

Marky - that EGR mod, can it really be done that simply?

I thought you had to take off the EGR pipe and stick a ball-bearing or a blocking plate in?

I would have thought that not recycling your exhaust gases would *increase* emissions????

YEAH you owe me a FIVER now

[BUSHWHACKER]

Also, make sure the engine is really hot before the emmisions test. Don't just drive down the road to the test centre , go for a blast along the motorway/dual carriageway first.

[JimSuperSix]

Fair enough then, I'll mod the EGR pipe if it's that simple.

Not sure about this veggie oil thing after reading the posts about it escaping through seals and stuff - is there a safe mix level (eg. 10%) or so that won't cause leaks but will also help the emissions?

What sort of veggie oil do you use, the stuff off the shelves at Tescos??

[stormforce]

Fair enough then, I'll mod the EGR pipe if it's that simple.

Not sure about this veggie oil thing after reading the posts about it escaping through seals and stuff - is there a safe mix level (eg. 10%) or so that won't cause leaks but will also help the emissions?

What sort of veggie oil do you use, the stuff off the shelves at Tescos??

just put in say 15l to start and fill with fuel.I think most of us use the Rapeseed oil.
I havent had any probs with the seals on my truck yet

[marky]

If you have no cable ties push a BOLT into the rubber pipe it acts as a BALL BEARING. All Bolts are THESPIANS

[JimSuperSix]

just put in say 15l to start and fill with fuel.I think most of us use the Rapeseed oil.
I havent had any probs with the seals on my truck yet

Cool, I'm very tempted to get a big drum of it from Tescos - from what I can find on the net it seems that so long as you use less than 2500 litres a year you don't need to inform the Inland Revenue, and at 54p a litre it will reduce my fuel bill by a fair amount.

Does it really bring your emissions down by a noticeable (by the MOT machine) amount?

[stormforce]

Cool, I'm very tempted to get a big drum of it from Tescos - from what I can find on the net it seems that so long as you use less than 2500 litres a year you don't need to inform the Inland Revenue, and at 54p a litre it will reduce my fuel bill by a fair amount.

Does it really bring your emissions down by a noticeable (by the MOT machine) amount?

mine was lower than last year when i bought it so it does lower it a bit

[nero279]

Does it really bring your emissions down by a noticeable (by the MOT machine) amount?

Nah it just makes the tester hungry so he rushes your MOT so he can get to the chippy

[Bogus]

Also, make sure the engine is really hot before the emmisions test. Don't just drive down the road to the test centre , go for a blast along the motorway/dual carriageway first.

As above, and apparently you have the right to have the smoke ( emissions) tests conducted on arrival at the testing station. You would need to arrange this in advance with them I presume. That way its being tested while at operating temps and immediately after a good blow through. If you do that, put in a wee bit of veg oil, do the EGR mod, Im sure you will pass.

Bogus

[WARRIOR72]

the oil temperature has to be around 80 degrees c before you can test most diesels ,tho this can be bypassed. emissions are always the first thing i do after logging the vehicle on the computer!!