Delinquent
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| posted on 26/9/08 at 09:50 AM |
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Use(less?) info for MOT time emissions.
Have a car that for the past 2 years has "struggled" to meet emissions (by struggled I mean some serious understanding and patience on the
part of the testing chap to coerce it through!)
This year, in a bid to give it the best shot possible, I gave it a full service and shake down - while buying the parts from the local MF the chap
asked me why I was doing a full service (he knows me, it's unusual for me to service a car  ) so I told him.
His nugget of info was to drain the tank and put a couple of gallons of the highest octane in we could find, and use magnitec oil instead of the
normal stuff.
Sceptical, but willing to try anything, I did.
Result - emissions passed with such a large margin the tester described it as "beautiful"!!! HC02 down from in excess of 3200 ppm to just
80 ppm, C02 down from 3% to 0.18% 
How much of that was down to the service and how much to the fuel is open to guess work, but as I'd tried oil and filters change the previous
year I reckon there is something in it.
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l0rd
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| posted on 26/9/08 at 10:05 AM |
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there can be so many reasons for failing on emissions. Most of the car fail cause they are not used properly most of the time such as travelling
around the city and not pushing the car at all.
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Mr Whippy
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| posted on 26/9/08 at 10:31 AM |
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you could help by giving it a good drive and a clean with redex. Magnatex is a good oil, I wonder just how much fumes end up coming from the crankcase
breather if you have hot old stinky oil in there?? Shell optimax fuel is very noticably better than something like tesco poop, I quite like using it
and thats all my bikes are ever run on as a rule.
Fame is when your old car is plastered all over the internet
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contaminated
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| posted on 26/9/08 at 10:32 AM |
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My hilux gets through every year by filling the fuel filter with Redex and giving it a good thrash up the road. Then I put 50% veg oil in the tank!
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Delinquent
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| posted on 26/9/08 at 10:35 AM |
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Should have noted in the original post - it had redex and a good thrash on the previous MOT's to get to the marginal state!
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Mr Whippy
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| posted on 26/9/08 at 11:04 AM |
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quote:
Originally posted by Delinquent
Should have noted in the original post - it had redex and a good thrash on the previous MOT's to get to the marginal state!
one of the things I've done with my bluebird is every single tank I have added redex to at the normal dosage, its only at 42k now, mine since it
read 25k. A few months ago I had the exhaust manifold off for cleaning & VHT painting (no really) and so had a look down the ports to see if my
feeding it constant redex had made a noticeable difference to build up. Well basically there was only light soot that wiped off with my finger, not a
drop of carbon build up at all and I could see the valves tops are also showing no build up so I'd say it was paying off. So I’ll be continuing
this practice from now on.
Fame is when your old car is plastered all over the internet
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Delinquent
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| posted on 26/9/08 at 11:06 AM |
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quote:
Originally posted by Mr Whippy
quote:
Originally posted by Delinquent
Should have noted in the original post - it had redex and a good thrash on the previous MOT's to get to the marginal state!
one of the things I've done with my bluebird is every single tank I have added redex to at the normal dosage, its only at 42k now, mine since it
read 25k. A few months ago I had the exhaust manifold off for cleaning & VHT painting (no really) and so had a look down the ports to see if my
feeding it constant redex had made a noticeable difference to build up. Well basically there was only light soot that wiped off with my finger, not a
drop of carbon build up at all and I could see the valves tops are also showing no build up so I'd say it was paying off. So I’ll be continuing
this practice from now on.
Interesting - think I'll take to that idea. The car in question is actually the wife's - a 92 Celica. Took us 18 months to find one in
such good nick with below average mileage (well, relatively, now at 80k!) so I'd like to give it the best shot at longevity in the family!
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MikeRJ
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| posted on 26/9/08 at 12:25 PM |
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quote:
Originally posted by Mr Whippy
Well basically there was only light soot that wiped off with my finger, not a drop of carbon build up at all and I could see the valves tops are also
showing no build up so I'd say it was paying off. So I’ll be continuing this practice from now on.
How much of this is down to modern fuels that contain cleaning agents?
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Mr Whippy
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| posted on 26/9/08 at 01:33 PM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by Mr Whippy
Well basically there was only light soot that wiped off with my finger, not a drop of carbon build up at all and I could see the valves tops are also
showing no build up so I'd say it was paying off. So I’ll be continuing this practice from now on.
How much of this is down to modern fuels that contain cleaning agents?
Well that’s a good question, but I do have other cars that are run regularly and they have shown build up even on good fuel. Beetle engines seem to be
very prone to carbon build up, usually needing the ports scraped. This is the first time I've seen none at all, even inside the manifold. Also
the carb is totally clean inside. Basically I think it's doing the engine a lot of good so I will continue doing so. It’s not even that
expensive or difficult to do. One note is that once opened the redex always seems to leak out so I keep the bottle in a plastic bag or it will stain
something.
Fame is when your old car is plastered all over the internet
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froggy
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| posted on 26/9/08 at 06:29 PM |
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90% of emmisions failures diesel or petrol need nothing more than abuse to get them through. as the closed loop system only works during steady state
running cat equipped cars are run in open loop for most of the time in urban driving and as cats age they dont get hot enough to work. my station does
20+ cars a day and i see plenty of cars running at 5-6%co and over 1000ppm hc come down to pass levels after sitting at 5k rpm for a minute or so.
petrol has a lot more detergents in now as we rarely see any injector faults on petrol engines compared to ten years ago
[IMG]http://i144.photobucket.com/albums/r187/froggy_0[IMG]
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MartynV
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| posted on 26/9/08 at 06:34 PM |
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The beetle engine is a slightly older design and air cooled, so you would expect more oil in the combustion chamber to cause carbon build up!
A modern engine running on semi or fully synthetic oil and good quality fuel generally does not suffer from carbon build up in the same way.
Wasting your money I reckon!!!
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Simon
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| posted on 26/9/08 at 06:51 PM |
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I have heard of a local place that, if faced with a problematic emissions car, stuff the probe up the tail pipe of a car that they know is
"clean"
ATB
Simon
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britishtrident
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| posted on 26/9/08 at 07:02 PM |
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Typical symptoms of the primary (upstream) Lambda sensor being past its best.
Generally after 5 years most Lambda sensors have slowed down to the extent that getting through an MOT requires getting the engine stonking hot. Like
a spark plug the lambda sensor gets covered in deposits, generally this dosen't stop the lambda sensor working it just slows its' response
time down
Normally the voltage output from the primary lambda sensor flickkers up and down from high to low and back in the blink of an eye. The cars ECU trys
to monitor the lambda sensors performance by taking a "crossing count". of the number time the signal changes in a given interval when
the engine is running closed loop however the Lambda sensor really has to be totally knackered to flag up a fault code.
More recent cars have 3 way catalysts which have an additional downstream Lambda sensor post cat the purpose of the downstream sensor is soley to
monitor the performance of the catalyst and primary Lambda sensor.
As a general rule once a primary Lambda sensor gets beyond 5 years old it is past its prime it will have slowed down to the extent that getting
through an MOT becomes more difficult and requires the car to be really stonking hot. A good ful throttle blast and heavy dose of detergent additive
helps but the long term remedy is a new OEM spec Lambda sensor.
[Edited on 26/9/08 by britishtrident]
[Edited on 27/9/08 by britishtrident]
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