NCT fail on emissions, will dipetane fix it?

Chimaera

samih wrote: »

The lambda is actually 1.01 i.e. slightly lean so it is not running rich. OP, your car suffers from very incomplete combustion for some reason so service is sound advice. New cat definitely won't fix the emissions. I'd start from ignition system and engine timing. Did the car have e.g. a new timing belt between this and the last NCT?

Looks like you didn't read the rest of the thread before posting....

Chimaera

Chimaera wrote: »

Looks like you didn't read the rest of the thread before posting....

It wouldn't be the first time. -- Reread the thread and my answer was meant for W.V.L 11. The CO and HC are sky high (incomplete combustion) and the lambda was slighty lean (O2 sensor and management doing their job trying to fight the underlying problem).

The cat may also well be damaged with all the unburnt petrol but even a perfect one can only do so much... A typical non-cat car has a CO of around 1-2 % and HC around 100 ppm which a working cat then takes down to 0.1 % and 10 ppm or better.

W.V.L 11: As your timing belt was changed so recently could it be the correct timing tools were not used?

Kenny Logins

jim-mcdee wrote: »

I think it has a placebo effect on people, and the stuff actually does f all.

So if you can employ any other method convincing yourself that your car will pass emissions, it will?

V.W.L 11

samih wrote: »

It wouldn't be the first time. -- Reread the thread and my answer was meant for W.V.L 11. The CO and HC are sky high (incomplete combustion) and the lambda was slighty lean (O2 sensor and management doing their job trying to fight the underlying problem).

The cat may also well be damaged with all the unburnt petrol but even a perfect one can only do so much... A typical non-cat car has a CO of around 1-2 % and HC around 100 ppm which a working cat then takes down to 0.1 % and 10 ppm or better.

W.V.L 11: As your timing belt was changed so recently could it be the correct timing tools were not used?

the belt was changed before i bought it,i done a major engine service this week and it does seem to run much much better,photos of spark plugs and oil on this thread

jca

V.W.L 11 wrote: »

the belt was changed before i bought it,i done a major engine service this week and it does seem to run much much better,photos of spark plugs and oil on this thread

It should pass easily now.

V.W.L 11

jca wrote: »

It should pass easily now.

i'll throw in a litre of dipetane for luck

jca

V.W.L 11 wrote: »

i'll throw in a litre of dipetane for luck

I wouldn't waste me hard earned bobs tbh..

V.W.L 11

jca wrote: »

I wouldn't waste me hard earned bobs tbh..

conflicting reports on the stuff then??!

jca

All your engine needed was a good service, not snake oil.

V.W.L 11

jca wrote: »

All your engine needed was a good service, not snake oil.

hopefully that proves to be the case on the retest

jca

V.W.L 11 wrote: »

hopefully that proves to be the case on the retest

I won't go as far as Dunphy but if it doesn't pass......I'll....:pac::pac:

V.W.L 11

jca wrote: »

I won't go as far as Dunphy but if it doesn't pass......I'll....:pac::pac:

hopefully i'll be :-)

spawinte

Limit for my diesel was 3.0 and I failed with a 6.2 first time out. Booked the retest for 4 weeks later. In the week before the retest I burned through half a tank of diesel treated with dipetane mixed at 150:1

I did lots of hard accelerations during my normal driving and kept the revs up using lower gears. I did a couple of evenings of high rev driving down the motorway at 120kph in 4th gear (3k rpm seems to work) and another 20 mile hard run before heading to the test centre.

Result ---> 1.8

Car is an 08 reg Peugeot 308 with the 1.6 diesel.

Chimaera

1.8 is still sky high for a '08 diesel. You've got problems in there.

twibbles

I recently failed my NCT on high emissions. I have decided to give the old Dipetane a shot. It's only a tenner a bottle after all. The car is a diesel by the way. I have seen mixed reports about this stuff on other threads however.

I will bring the car for an emissions test at Fast Fit or wherever in a week or so. Just to see if this miraculous Dipetane is making any difference.

It seems that it is advisable to make sure that the engine is has heated fully before the test also. So, I will do that also. I will report back and let you know how it all goes.

twibbles

I brought the car for in for an emissions test over the weekend after treating the diesel with dipetane and going for a few long drives up the motorway during the week. The result was under 3.0 although not by a whole lot.

That's low enough to pass the NCT however. I will report back again after the re-test. Finger crossed!

The guy who did the test didn't think that dipetane was much use by the way. He was surprised that the emissions had more than halved. There are better products on the market apparently although they are more expensive.

flutered

back in the day when i had a series of pug 405's, i used to turn down the pump as i got the test center, worked every time, it may not have traveled the last 100 yards very fast, put they always passed

tphase

flutered wrote: »

back in the day when i had a series of pug 405's, i used to turn down the pump as i got the test center, worked every time, it may not have traveled the last 100 yards very fast, put they always passed

did the same with my 405's, never failed a test:D

twibbles

twibbles wrote: »

I brought the car for in for an emissions test over the weekend after treating the diesel with dipetane and going for a few long drives up the motorway during the week. The result was under 3.0 although not by a whole lot.

That's low enough to pass the NCT however. I will report back again after the re-test. Finger crossed!

The guy who did the test didn't think that dipetane was much use by the way. He was surprised that the emissions had more than halved. There are better products on the market apparently although they are more expensive.

Well anyhow, I said that I would report back on this. My car passed the NCT a few days ago

Now, I'm not sure if it's 100% down to the Dipetane because I had driven a fair distance before the test this time, and I sat with the car idling for a while before I headed in also so the engine was quite hot. But, a pass is a pass at the end of the day.

I will get it looked at before next year's test probably because there must be something up on the combustion front.

bauney

Hi. My 03 corolla hatchback diesel failed nct due to emissions. It read 4.5 and limit was 2.5
I asked around and decided that dipetane was best option. I was really unsure if this would work so I put in about 400ml (4 units) of dipetane to 40 litres approximately.
Then the fun started. I drove the car harder (up to 3/4k revs) than normal for week or so doing about 200 miles. Rarely in 5th gear. Blowing smoke out to beat the band.
Anyways today I did the retest and I got a reading of 0.5.
Make your own conclusions our of that . Either 1) dipetane did the magic
2) driving hard did the trick
3) or a mix or them

But I am delighted to say the least.

Now I just have to insure the car which I got made aware that it's will cost me over 700 for 3rd party. Was only over 300 couple years ago. Scandalous

demanufactured

twibbles wrote: »

Well anyhow, I said that I would report back on this. My car passed the NCT a few days ago

Now, I'm not sure if it's 100% down to the Dipetane because I had driven a fair distance before the test this time, and I sat with the car idling for a while before I headed in also so the engine was quite hot. But, a pass is a pass at the end of the day.

I will get it looked at before next year's test probably because there must be something up on the combustion front.

You still have a problem thats probabaly wasting fuel as well.
i'd be inclinded to get it looked at sooner rather than later.

twibbles

How quickly time just flies by ...

I am due my NCT next month. So, I took the car for an emissions test earlier in the week and it failed badly. The mechanic's advice was to lob a whole bottle of dipetane in with a full tank of fuel. So, I took his advice. I was surprised because on the bottle it recommends mixing it 1:200 parts of fuel. Anyway, he said that it would be grand and I have driven a bit since without any issues.

I will report back following the NCT.

@demanufactured - The car was fully serviced relatively recently and the fuel economy is good. However, if the dipetane doesn't do the trick this year also I may get some work done. It's an old car (diesel) and it doesn't get driven much so it's probably not worth spending a whole lot of money on it. I might just replace it also although I'd rather not.

The attitude of owners of diesels that are spewing out black smoke is something else. My 220k miles 15 year old diesel sprinter without DPF had a reading of 0.6/3.0 allowed. That's after the result had crept up towards 1.0 after which I replaced the injectors to get it down towards smokeless again. If your diesel is struggling to get a result under 3.0 you really need to sort out the broken fuel system or engine, ffs.

twibbles

samih wrote: »

The attitude of owners of diesels that are spewing out black smoke is something else. My 220k miles 15 year old diesel sprinter without DPF had a reading of 0.6/3.0 allowed. That's after the result had crept up towards 1.0 after which I replaced the injectors to get it down towards smokeless again. If your diesel is struggling to get a result under 3.0 you really need to sort out the broken fuel system or engine, ffs.

Yes. You are right. I am planning on getting it looked at. Hopefully it won't cost an arm and a leg.