Thinking about MOT & Emissions...

[trufflehunt]

Hi

I've owned the 406 through 3 MOT's.
2013, and 2014... I popped some Cataclean into the tank a couple of days before MOT,
and on the day, before heading for the garage, I gave the car a 15 mile blast on the M5.
No problems with emissions.

February 2015. Again I put the Cataclean in a few days before. On the day, I left home later than intended,
and was unable to fit in the Italian tune up, and made do with getting the car up to working temp over a few miles.

Car passed MOT OK.
However, as I paid, the garage bloke said that they'd had a bit of difficulty with the emissions, and had
got them down with some Fortis.( trade-only version of stuff such as Cataclean, etc..).
So that was £10 or £12 on top of the MOT.

I only noticed a few days later that they hadn't given me an 'emissions levels sheet' along with the MOT certificate
like they had done on previous occasions.

I'm just wondering, 4 months before next MOT, whether I should be thinking about emissions levels, and what to do ?
Or whether this was just an easy way for the garage to make a few quid on top of the MOT. (they have a good reputation
locally, and I've had no problems with them over my last several cars).

Most of my regular mileage is from a rural small town 9 or 10 miles each way along rural A-roads, or back roads... to bigger towns.
Very little high speed, mileage-eating stuff.

Should I be worrying, and need to take some actions prior to next MOT?

[Doggy]

I never do any prep for emissions testing and have never had a problem. To be fair I do 60 miles a weekday to work & back on A roads / dual carriageways so it's maybe not surprising I don't have any difficulty. I would have thought all you reasonably need to do is give it a decent run to blow the cobwebs out.

Seems odd they didn't give you the sheet, I've always had one and it always shows a reading of under half the permitted level on the first attempt. That's been the case for every MOT on both my 406's, starting in January 2009.

[Welly]

That's a bit weird if you ask me, sloshing in a bottle of Forte is unlikely to improve emissions 'in the workshop' you'd have to go on a decent run to see the effect I'd say. And you can't stop an MOT once it's started as it's kinda timed so you can't 'nip out' for a run etc....

If I was critical I'd say the emissions were 'elevated' so you were sold a bottle of Forte for good measure and not for the purpose of passing the test.

[Bailes1992]

CATACLEAN is for petrol engine cars as far as I'm aware. Also the CAT makes no difference to the emissions testing of diesels.

If your diesel is failing the smoke test then something isn't right. Smoke is caused by too much fuel or lack of air, it's the inability to burn efficiently.

Possible causes?
Boost leak - check all your post turbo pipework, it's a 110 so make sure you give the intercooler a good inspection.
Air filter - Make sure it's not dirty.
EGR - could be jammed open and letting exhaust gasses recirculate all the time. Clean or blank it off.
Inlet manifold - After 15 years with an EGR it's likely that it's sooted up. Probably a wise idea to remove and clean.
Injectors - Perform a leak off test. It's an easy DIY job, cheap too and will tell you if you have a seriously faulty injector(s)


If you do want to use an additive then I highly recommend BG 244. It's not cheap but it does work. It's around £20-£25 a can.
I used two one after the other in my Mondeo at 140k. First one went in and I tanked up and drove from Bridgend to Bruges, to Penryn and back to Bridgend where I tanked up again with the second can. About a week into the second can with my standard commute I booted it up a steep hill and a huge amount of thick black soot came out the rear end. After that the turbo spooled faster ad the car was quite and more responsive. Highly recommended.

If you want a regular use additive then Google two stroke mineral oil in diesel. Mercedes took a hand full of brand new E or S classes from Paris to Beijing and we're worried about the quality of diesel in the far Eastern parts of the world so used two stroke oil mixed in with the diesel. They found the cars ran much smoother, cleaner, performed better and we're quieter.

[PeterN]

Sounds a bit suspicious to me. The Hdi is a pretty clean burning engine, all I have ever found necessary is to push it a bit on the way to the MOT and it blows all the loose soot out of the exhaust. As mentioned you would need to have something seriously wrong with it for it to fail a smoke test - but not a soot test!

Peter

[lozz]

Car passed MOT OK.
However, as I paid, the garage bloke said that they'd had a bit of difficulty with the emissions, and had
got them down with some Fortis.( trade-only version of stuff such as Cataclean, etc..).
So that was £10 or £12 on top of the MOT.
....................................................
^ they added it withought informing you first?

[jasper5]

Just give the car a blast up the road before you take it for test and keep the engine running whilst you wait for the car to be tested....no need for expensive cleaners.
To be honest, my 110 HDi Expert Van always shows high on the emission test until my tester revs the engine about 5 times...he revs it 3 times if it doesn't pass on the first rev then 5 if it doesn't pass on the 3rd rev.
The emissions always come within pass limits by the 5th rev.
If I take a customer's car and it doesn't pass he just keeps revving it until it does...it always comes down.
I haven't used a cleaner for a long time now....they will work straight away to lower the emissions, but so will revving the engine a little less...this will show a lower reading!!

Some Renaults and later VW, along with Volvo and some Fords will not rev high enough to give a high reading on the emissions.
I took a Passat last week for mot which read zero on the emission test...the engine just doesn't rev from tickover!!

[Welly]

I took a Passat last week for mot which read zero on the emission test...the engine just doesn't rev from tickover!!

Maybe the Passat knew it was at an MOT centre

[Bailes1992]

I try not to use additives that much. I use premium diesel the majority of the time and once every 6000miles I pop a can of BG 244 in.

Americans love their additives and they're doing something right as they get much higher mileages out of their cars than we do.

[trufflehunt]

Car passed MOT OK.
However, as I paid, the garage bloke said that they'd had a bit of difficulty with the emissions, and had
got them down with some Fortis.( trade-only version of stuff such as Cataclean, etc..).
So that was £10 or £12 on top of the MOT.
....................................................
^ they added it withought informing you first?

Indeed. But as the car had passed, I chose not to argue the point.

[lozz]

Car passed MOT OK.
However, as I paid, the garage bloke said that they'd had a bit of difficulty with the emissions, and had
got them down with some Fortis.( trade-only version of stuff such as Cataclean, etc..).
So that was £10 or £12 on top of the MOT.
....................................................
^ they added it withought informing you first?

Indeed. But as the car had passed, I chose not to argue the point.

isee your point,

ive landed for the bulb out (Blag) a few times,

you had a number plate & side light bulb out sir...we thought rather than fail it..we'd change the bulbs for you.,

They wasnt out..to begin with.
£20 for two..50p bulbs.

Back on topic of the emissions test... do they mark it down as an advisory if its only just scraped through?

[trufflehunt]

Back on topic of the emissions test... do they mark it down as an advisory if its only just scraped through?

The only advisory on mine was for front disc pads getting low.
On my various perusing of eBay listings, I don't recall ever seeing an emissions advisory on the
photos of MOT sheets.

[trufflehunt]

Thanks for all replies and suggestions chaps.

What I've decided to do is......

Bearing in mind that I've never had any problems at all with emissions on previous tests,
and the circumstances this time seem rather doubtful,
and the HDI doesn't seem over-prone to this problem,
and the car is running fine....

I'm reluctant to start pulling things apart.

So here's what I'll do.

1. For several weeks before the MOT at the end of February,
I'll fill up with 'super' diesel from a branded filling station, rather than concentrating
on whether I can save 0.1 pence per litre at either Morrisons or Asda.

2. I"ll spray in some EGR cleaner.

2. Cataclean is for diesel and petrol. I'll add a bottle of that a couple of days before.

3. Make sure that I give it the good ragging down the motorway immediately prior to the test.

Thanks again guys.

[Bailes1992]

Forget the CATACLEAN. It's for revitalising CATs. It won't help your emissions issue.

Go to KwikFit and get a can of BG 244. Awesome stuff, have a Google.

Other option would be a few does of two stroke oil, again have a Google.

[jasper5]

I took a 2010, 308 for mot today....reading was zero on the emissions.