Tuning JTD Emissions

[haxman]

My 2002 JTD (144k miles) failed the MOT today on emissions (and rear axle bushes sadly). The average emissions reading was 2.11 1/m and since the new stricter MOT has come into force the limit has now been reduced from about 3 1/m (i think) down to 1.34 1/m. The tester suggested fuel additives may help bring it down.

Has anyone got any experience with additives? I just had a quick look on Eurocarparts, and there seem to be a lot on the market. Any recommendations for what works best? The tester mentioned filling up a new fuel filter with additive to send it through neat seems a bit dodgy to me, or is this a safe/recommended practice?

I have recently removed the egr blanking plate that was fitted, I gave it all a good clean up, including the MAP sensor, ( I didn't remove or clean the intake manifold though). I seem to be getting better MPG now then I was previously. I assume refitting the EGR blanking plate would make the emissions worse, is that correct? Aside from running an additive through, and driving it hard for a while, is there any other advice for reducing emissions?

Many thanks.

 

[cris1117]

An old trick that’s been used for years. Before you go for an MOT find somewhere quite and rev the nuts out of the engine I mean foot to the floor for a few seconds, the first rev will give lots of black smoke the second not so much etc.
I usually do mine on the way to the test centre four or five times usually makes it rev clear, just make sure no one is behind you.
You may well destroy the planet with all the soot but the car will have an MOT.

 

[haxman]

find somewhere quite and rev the nuts out of the engine I mean foot to the floor for a few seconds,

Thanks for the tip. To be fair, the tester was reving it quite high, not as much as that, but he did give it some beans. I'll try an additive, and a heavy right foot...

Can anyone recommend a good additive? Is 1.34 1/m easily achievable on a well used JTD?

 

[g8rpi]

Thanks for the tip. To be fair, the tester was reving it quite high, not as much as that, but he did give it some beans. I'll try an additive, and a heavy right foot...

Can anyone recommend a good additive? Is 1.34 1/m easily achievable on a well used JTD?

Hi,
I think the garage may have got it wrong. Unless there is a smoke value on the vehicle data plate the limit for a pre 2008 turbo diesel is 3.0. See https://www.gov.uk/government/publi...n-limits#new-default-limit-for-newer-vehicles
for more info. 1.34 seems a little low for a non DPF engine. If it is 1.34 on the plate fit a new air filter if it is more than 6 months old. Low cost, easy to fit and can mke a big difference.

Personally I have had good results with Millers additives. I use their Diesel power Ecomax every few tanks and a couple of tanks before MOT time, bu for your needs their "Diesel Power EcoMax One Shot Boost" looks like a better choice. https://www.millersoils-shop.co.uk/diesel-power-ecomax-one-shot-boost



Robert G8RPI.

 

[haxman]

Thanks very much Robert, sadly I don't think the garage have got it wrong, I did question the emissions limit, and the tester said he got the value from the data plate under the bonnet, I haven't checked this, but I assume its correct. I guess all JTD Stilos will now be tougher to get through on emissions?

I'll certainly look up Diesel Power EcoMax One Shot Boost, sounds like just the thing I'm after, thanks for the recommendation. Yes I wondered about air filter too, I'll pick one up and see where that gets me.

Thanks again.

 

[chris3234]

I think all disels are tested to the smoke limit on the date plate now
Unless one isn't fitted then defaults to the old test limit's

 

[Artermis]

Hi,
I think the garage may have got it wrong. Unless there is a smoke value on the vehicle data plate the limit for a pre 2008 turbo diesel is 3.0. See https://www.gov.uk/government/publi...n-limits#new-default-limit-for-newer-vehicles
for more info. 1.34 seems a little low for a non DPF engine. If it is 1.34 on the plate fit a new air filter if it is more than 6 months old. Low cost, easy to fit and can mke a big difference.

Personally I have had good results with Millers additives. I use their Diesel power Ecomax every few tanks and a couple of tanks before MOT time, bu for your needs their "Diesel Power EcoMax One Shot Boost" looks like a better choice. https://www.millersoils-shop.co.uk/diesel-power-ecomax-one-shot-boost



Robert G8RPI.

This is correct.

A common 'trick' now being employed by a lot of the BMW / MG / Rover gangs running the rubbish 2.0 diesel found in the e46 generation ZT / 75 rovers is that they are putting a piece of electrical tape over the emissions value on the chassis plate.

MOT testers aren't allowed to remove anything, so if it's blanked over or sanded off or whatever then it can't be read.

That means the tester has to use the default, higher value which the car can pass, as they don't seem to be able to meet the values on the chassis plate now they've aged a little.

 

[puntofan01]

At risk of sounding ignorant, surely any car would only have to meet the Euro emissions standard of its year of manufacture in order to get through the MOT?

 

[chris3234]

At risk of sounding ignorant, surely any car would only have to meet the Euro emissions standard of its year of manufacture in order to get through the MOT?

.2 What you need to know
The amended limits to be applied from 20 May 2018 are:

1. First used before July 2008 None turbo 2.5m-1 or plate value if lower
Turbo 3.0m-1 or plate value if lower
2. First used on or after 1 July 2008 All diesels 1.5m-1 or plate value if lower
3. First used on or after 1 January 2014 All diesels 0.7m-1 or plate value if lower


These is how disels are tested now
Most are based off the smoke limit for the car if one is fitted

 

[haxman]

putting a piece of electrical tape over the emissions value on the chassis plate.

I did wonder about doing exactly that. I wish I had now, but I didn't know whether or not the chassis plate on my car would dictate a new emissions limit. I should have researched and found out. I've just looked at the plate now and yes there is a box on the bottom left which has the number 1.34 in it, so I guess that's it. I assume this would be the same on all 8v 115 JTD Stilos?

I think a strategically spilt drop of paint my have to happen for next year assuming I get it through now. What would happen if said chassis plate was covered over for when I go to the retest? He has already tested it for the new limit.

 

[Ralf S.]

Gerrard (2004 JTD) has the dreaded "1.34" on the plate too.

I can't remember what he did last time out but I'm a bit worried now..


After my MOT I must have been spooked though. I used some Cataclean stuff after my MOT after asking for advice on here;

https://www.ebay.co.uk/itm/Cataclea...-500ml-/132148518060?var=&hash=item1ec4aa5cac

It did seem to clean out a lot of gunk. They say you have to work the engine a bit (without going crazy about it) to help the goo shift the soot but it did seem to do something. My car produced more smoke and soot while I was using it and afterwards it went smokeless for a while and seemed to just breathe more easily.

Smoke/emissions is worse if you are gentle on the car. Since I'm an old(ish) fella I rarely venture past 2500rpm in normal driving. I've taken to booting it a bit to 3,250/3,500 at one particular junction on my way home every evening, which always gives me a puff of black smoke in the mirror.. but it's reduced if I do it daily.. worse if I forget for a few days.

So, prior to MOT it's definitely worth getting it hot and then using some rpm. I don't see any improvement from over-revving or doing it all the time.. it just needs some exercise, rather than being flogged to death.

Otherwise, emissions is basically the air filter (replace - cheap), MAP sensor (clean it - free), inlet manifold (pools with oil if you run your oil level at MAX and this can pollute the MAP, so clean it - free).

You might also have to look at the MAF.. my old beast suddenly gained 5 or 6 mpg when I changed it so even though you have to pay out £80 or more for a genuine Bosch (nothing else is worth having) it quickly pays for itself and the car runs better too.

Also if you have a new Lambda and Cat' lying around....... but these are kind of last ditch/expensive ways to do it.

I'm thinking that next time I might experiment with a new "MOT-only" lambo' and Cat' if I can afford them... then put the old components back on for the rest of the year, so that the new ones don't get worn out for the following year's MOT... Or maybe a tea-strainer over the end of the exhaust tip...? I dunno.. I'll try anything!


Ralf S.

 

[haxman]

Ha ha thanks for the reply and tips Ralf. I don't really want the hassle of changing too much, so I guess I'll start with air filter, fuel filter, and an additive, I'll get it nice and hot and see where that gets me. I can see the "dreaded 1.34" catching a lot of people out.

 

[aurick86]

Change OIL and filters before emissions testing.

Oil traps a lot of crap in it. the small amount that burns off will give bigger emissions than clean oil.

 

[cris1117]

Thanks for the tip. To be fair, the tester was reving it quite high, not as much as that, but he did give it some beans. I'll try an additive, and a heavy right foot...

Can anyone recommend a good additive? Is 1.34 1/m easily achievable on a well used JTD?

That’s exactly why it failed the emissions test; the first couple of hard revs will blow lots of soot out of the exhaust, after four or five hard revs it will blow clean.

 

[Ralf S.]

Testers usually rev it up a few times before they measure it, so that the initial cloud of soot doesn't clog up their probe..


Ralf S.

 

[haxman]

That’s exactly why it failed the emissions test; the first couple of hard revs will blow lots of soot out of the exhaust, after four or five hard revs it will blow clean.

Ok thanks, I'll make sure I get it nicely blown out before I arrive for the retest.

 

[cris1117]

The testers won’t rev it hard enough because they don’t know if the cam belt has been maintained properly and are frightened of snapping it.


I usually do mine at least five times on the way to the test centre no one behind in to neutral and rev it hard just for a second, clouds of black smoke. It’s also a neat way to get rid of tailgater’s car full of fumes,they soon back off.


The car has a rev limit that it won’t exceed so providing the car is properly maintained it can’t damage the engine.

 

[haxman]

A common 'trick' now being employed by a lot of the BMW / MG / Rover gangs running the rubbish 2.0 diesel found in the e46 generation ZT / 75 rovers is that they are putting a piece of electrical tape over the emissions value on the chassis plate.

Just wondering if its allowable to put a 'cover' over ones VIN plate which hides it? From what I've been reading, it needs to be visible to an MOT tester, is this correct? I guess covering the emissions value only is OK-ish as long as the tester can see the identifying details?

 

[haxman]

So I took my car for the retest yesterday, to get the emissions down I changed the oil and filter, gave it a new air filter, and replaced fuel filter. I also added some additive. I got it nice and hot before I arrived, and when we did the emissions test, the end result was 0.74 1/m, down from 2.11 1/m and well under 1.34 1/m on the chassis plate :slayer: Nice to know it is achievable to get under the threshold, thanks for all the tips.

 

[Ralf S.]

My old beast managed 1.46 last year... so it'll be an interesting MOT for him in December..


Ralf S.