Help - Scirocco Emissions Problem
Discussion
I have a 2 litre petrol 200PS Scirocco (CAW engine code, which is EURO-5 compliant I believe). I've had it from new. It’s completely standard and only done 22000 miles.
Had a service and MoT today at the main dealers and initially it failed the emissions test "Exhaust emissions Lambda reading after 2nd fast idle outside specified limits (7.3.D.3)". They gave it a run and tried again and it just scraped through. I don't have the emissions printout at the moment so I don't know the Lambda value (the values from the 3 previous MoTs were 1.011 (2012), 1.003 (2013) and then 1.006 (2014) – I notice that these were from a different MoT station to today’s). The emissions light has never come on and a scan brings up no faults and it drives the same as it always has.
I'm wondering if the fact that it’s done only 1700 miles in the last year and the fuel (Tesco’s Momentum) in the tank is about 4 months old could affect the emissions or if the readings are wrong somehow. I’m not sure where to go from here – if there’s a problem then I’d like to resolve it now rather than wait for the light to come on or for it to fail next year.
Any thought/ideas gratefully accepted.
Had a service and MoT today at the main dealers and initially it failed the emissions test "Exhaust emissions Lambda reading after 2nd fast idle outside specified limits (7.3.D.3)". They gave it a run and tried again and it just scraped through. I don't have the emissions printout at the moment so I don't know the Lambda value (the values from the 3 previous MoTs were 1.011 (2012), 1.003 (2013) and then 1.006 (2014) – I notice that these were from a different MoT station to today’s). The emissions light has never come on and a scan brings up no faults and it drives the same as it always has.
I'm wondering if the fact that it’s done only 1700 miles in the last year and the fuel (Tesco’s Momentum) in the tank is about 4 months old could affect the emissions or if the readings are wrong somehow. I’m not sure where to go from here – if there’s a problem then I’d like to resolve it now rather than wait for the light to come on or for it to fail next year.
Any thought/ideas gratefully accepted.
http://www.crypton.co.za/Tto%20know/Emissions/lamb...
IIRC, FSI engines are prone to coking in the intake. Lots of short journeys where the engine never gets chance to warm up aren't going to be good for it's health in any case.
Has anyone had that Terraclean thing done? Some people swear by it, others say it's snake oil.
IIRC, FSI engines are prone to coking in the intake. Lots of short journeys where the engine never gets chance to warm up aren't going to be good for it's health in any case.
Has anyone had that Terraclean thing done? Some people swear by it, others say it's snake oil.
My GTi had this coking issue, a couple of attempts at cleaning it failed, an Italian tune up helped after the last attempt on a couple of really long runs.
We ended doing regular long trips over a couple of months and I think this just cleaned it out. Never had it again but then I also stopped the silly short journeys, this was some 3 years and 30K miles ago.
We ended doing regular long trips over a couple of months and I think this just cleaned it out. Never had it again but then I also stopped the silly short journeys, this was some 3 years and 30K miles ago.
Annoyingly neither the dealer or the MOT station can provide the emissions test printout so I'm lacking the full picture. I think they are supposed to give you this under the MOT rules so I'm going to chase them again to either get the original print or retest the emissions.
There was also an MOT advisory for "Centre Exhaust has a minor leak of exhaust gases (7.1.2)". When I spoke to the MOT tester he said that this could be affecting the emissions. I'm sceptical of this because the leak would be downstream of the cat and the Lambda sensors anyway. Whatever gas leak there is must be very small because there's nothing audible even underneath the car.
It's not just doing really short journeys (typically around 30 miles) so I don't think I have the coking problem but maybe a good long run to get the cat hot for a while will help.
I thought about trying this stuff http://www.cataclean.com/emissions-crusade/new-loo... to clean the cat and I wonder if anyone has experience of it.
There was also an MOT advisory for "Centre Exhaust has a minor leak of exhaust gases (7.1.2)". When I spoke to the MOT tester he said that this could be affecting the emissions. I'm sceptical of this because the leak would be downstream of the cat and the Lambda sensors anyway. Whatever gas leak there is must be very small because there's nothing audible even underneath the car.
It's not just doing really short journeys (typically around 30 miles) so I don't think I have the coking problem but maybe a good long run to get the cat hot for a while will help.
I thought about trying this stuff http://www.cataclean.com/emissions-crusade/new-loo... to clean the cat and I wonder if anyone has experience of it.
Edited by PGN on Tuesday 5th May 20:34
Your getting mixed up by the terminology of the emissions data
The "lambda" reading on the mot test has nothing to do with the sensors on the car it is the level of oxygen in the exhaust gasses coming out the tailpipe
An exhaust blow will effect this reading & can cause a fail on the mot test
The "lambda" reading on the mot test has nothing to do with the sensors on the car it is the level of oxygen in the exhaust gasses coming out the tailpipe
An exhaust blow will effect this reading & can cause a fail on the mot test
Neil is only a few miles from me so I arranged for him to have a look at the car. He found a minute exhaust leak when cold, which sealed completely as the car warmed up. He retested the emissions and the results were absolutely perfect so I'm not sure what happened when the car was MOTd. Anyway I can't recommend Neil https://www.facebook.com/NWJAutocare highly enough. He seems like a really genuine, knowledgeable guy (and he didn't charge me anything!).
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