Emissions test levels - MOT
Discussion
Hi, I've got a VW Golf with the 1.9 BKC engine. Today it failed its MOT just on the emissions test. The plate value for emissions limit is 0.8 which I think is optimistic anyway.
They tried 6 times today, results as follows
2.15
1.94
1.48
1.47
1.51
1.61
so first test lot, high of 2.16 and a low of 1.47.
It's had a recent oil and oil filter change, since the garage asked, but I can't see that having anything to do with emissions.
So I took a look at the air filter, which needed doing, but I've seen worse, so I replaced that. The fuel filter was totally black, so I replaced that.
The MOT station then retested the emissions which came down to a high of 1.24 and a low of 1.12, so it's made a difference, but not quite enough.
Can anyone suggest what else I could do? The garage couldn't give much advice as they only do MOTs, so can't massage it through.
Thanks
They tried 6 times today, results as follows
2.15
1.94
1.48
1.47
1.51
1.61
so first test lot, high of 2.16 and a low of 1.47.
It's had a recent oil and oil filter change, since the garage asked, but I can't see that having anything to do with emissions.
So I took a look at the air filter, which needed doing, but I've seen worse, so I replaced that. The fuel filter was totally black, so I replaced that.
The MOT station then retested the emissions which came down to a high of 1.24 and a low of 1.12, so it's made a difference, but not quite enough.
Can anyone suggest what else I could do? The garage couldn't give much advice as they only do MOTs, so can't massage it through.
Thanks
Tony1963 said:
Which fuel is in it? Supermarket? If so, try a tankful of Shell or BP maybe.
Injector cleaner/diesel treatment.
How many miles on the engine.
Sometimes regular supermarket, in my other car it's lived off Costco premium and has been fine.Injector cleaner/diesel treatment.
How many miles on the engine.
It's got about 108k on the clock. I could try a cleaner, have been reading about Dipetane and possibly an EGR clean.
Seeing as it's a ridiculous test, I have no problem in suggesting a ridiculous solution.
Get it up to temperature.
Renew the fuel filter (or empty your recently new one) and fully fill it with 'injector cleaner' (it will need more than one can).
Immediately drive it hard staying in low gears to the MoT station for the Retest, and pray they're ready for you... if they're sympathetic this can be agreed in advance...
Good luck.
Get it up to temperature.
Renew the fuel filter (or empty your recently new one) and fully fill it with 'injector cleaner' (it will need more than one can).
Immediately drive it hard staying in low gears to the MoT station for the Retest, and pray they're ready for you... if they're sympathetic this can be agreed in advance...
Good luck.
AntTPIV8 said:
All figures are in the first post.
No they aren't.You've just listed a bunch of numbers. Probably only from one sensor, but you've left us to guess which one.
If you want any sort of diagnosis, share all the readings. That means CO, HC, Lambda and test description for each test.
GreenV8S said:
AntTPIV8 said:
All figures are in the first post.
No they aren't.You've just listed a bunch of numbers. Probably only from one sensor, but you've left us to guess which one.
If you want any sort of diagnosis, share all the readings. That means CO, HC, Lambda and test description for each test.
Make sure it’s not got any boost leaks; Even minor ones seem to cause a noticeable difference.
When checking, look for fresh oil leaking along the pipes or from the joints. If you do see any, it indicates somewhere that might need attention.
The quick disconnect bayonet/horseshoe joints wear away the lugs on the connectors and they start to leak boosted air. Lost air generally = less complete combustion of fuel.
You can bodge them with a set of new o-rings for them and some self tappers in the right places to hold everything together.
Check inside the pipes. If the amount of oil is excessive, the turbo seals could be passing oil which will be getting partially burnt, worsening the readings and clogging various parts of the engine over time.
Short term, a catch can will help manage that symptom, long term it would need the turbo sorting.
Removal and cleaning out of the egr might help.
There’s the old mr.muscle trick for cleaning out the turbos if they’re getting clogged up and the vanes in them aren’t actuating well. It does work but use it your own risk.
Are there any noticeable issues with the engines general running? Poorer mpg than expected, uneven idling, lack of power or laziness in coming on boost?
VCDS and a cheap interface cable would probably give some easy insight as to contributory issues that might need sorting.
When checking, look for fresh oil leaking along the pipes or from the joints. If you do see any, it indicates somewhere that might need attention.
The quick disconnect bayonet/horseshoe joints wear away the lugs on the connectors and they start to leak boosted air. Lost air generally = less complete combustion of fuel.
You can bodge them with a set of new o-rings for them and some self tappers in the right places to hold everything together.
Check inside the pipes. If the amount of oil is excessive, the turbo seals could be passing oil which will be getting partially burnt, worsening the readings and clogging various parts of the engine over time.
Short term, a catch can will help manage that symptom, long term it would need the turbo sorting.
Removal and cleaning out of the egr might help.
There’s the old mr.muscle trick for cleaning out the turbos if they’re getting clogged up and the vanes in them aren’t actuating well. It does work but use it your own risk.
Are there any noticeable issues with the engines general running? Poorer mpg than expected, uneven idling, lack of power or laziness in coming on boost?
VCDS and a cheap interface cable would probably give some easy insight as to contributory issues that might need sorting.
GreenV8S said:
No they aren't.
You've just listed a bunch of numbers. Probably only from one sensor, but you've left us to guess which one.
If you want any sort of diagnosis, share all the readings. That means CO, HC, Lambda and test description for each test.
Yes they are, that's all they did and all that's written on the report. If you don't know, that's absolutely fine.You've just listed a bunch of numbers. Probably only from one sensor, but you've left us to guess which one.
If you want any sort of diagnosis, share all the readings. That means CO, HC, Lambda and test description for each test.
TwinKam said:
Seeing as it's a ridiculous test, I have no problem in suggesting a ridiculous solution.
Get it up to temperature.
Renew the fuel filter (or empty your recently new one) and fully fill it with 'injector cleaner' (it will need more than one can).
Immediately drive it hard staying in low gears to the MoT station for the Retest, and pray they're ready for you... if they're sympathetic this can be agreed in advance...
Good luck.
I did consider doing that and wondering if it's a good idea to do so or not.Get it up to temperature.
Renew the fuel filter (or empty your recently new one) and fully fill it with 'injector cleaner' (it will need more than one can).
Immediately drive it hard staying in low gears to the MoT station for the Retest, and pray they're ready for you... if they're sympathetic this can be agreed in advance...
Good luck.
Demelitia said:
Make sure it’s not got any boost leaks; Even minor ones seem to cause a noticeable difference.
When checking, look for fresh oil leaking along the pipes or from the joints. If you do see any, it indicates somewhere that might need attention.
The quick disconnect bayonet/horseshoe joints wear away the lugs on the connectors and they start to leak boosted air. Lost air generally = less complete combustion of fuel.
You can bodge them with a set of new o-rings for them and some self tappers in the right places to hold everything together.
Check inside the pipes. If the amount of oil is excessive, the turbo seals could be passing oil which will be getting partially burnt, worsening the readings and clogging various parts of the engine over time.
Short term, a catch can will help manage that symptom, long term it would need the turbo sorting.
Removal and cleaning out of the egr might help.
There’s the old mr.muscle trick for cleaning out the turbos if they’re getting clogged up and the vanes in them aren’t actuating well. It does work but use it your own risk.
Are there any noticeable issues with the engines general running? Poorer mpg than expected, uneven idling, lack of power or laziness in coming on boost?
VCDS and a cheap interface cable would probably give some easy insight as to contributory issues that might need sorting.
I will do an EGR clean, it's got to help.When checking, look for fresh oil leaking along the pipes or from the joints. If you do see any, it indicates somewhere that might need attention.
The quick disconnect bayonet/horseshoe joints wear away the lugs on the connectors and they start to leak boosted air. Lost air generally = less complete combustion of fuel.
You can bodge them with a set of new o-rings for them and some self tappers in the right places to hold everything together.
Check inside the pipes. If the amount of oil is excessive, the turbo seals could be passing oil which will be getting partially burnt, worsening the readings and clogging various parts of the engine over time.
Short term, a catch can will help manage that symptom, long term it would need the turbo sorting.
Removal and cleaning out of the egr might help.
There’s the old mr.muscle trick for cleaning out the turbos if they’re getting clogged up and the vanes in them aren’t actuating well. It does work but use it your own risk.
Are there any noticeable issues with the engines general running? Poorer mpg than expected, uneven idling, lack of power or laziness in coming on boost?
VCDS and a cheap interface cable would probably give some easy insight as to contributory issues that might need sorting.
Otherwise the car runs well, can get it to 60mpg, pulls away fine, idles nice and smooth. If I floor it and look in the rear view, no smoke is visible.
AntTPIV8 said:
My replacing the air filter and fuel filter brought the reading down by about 0.4, so hopefully an EGR clean and running some cleaner through the fuel tank can get us another 0.4 or better.
Just follow my suggestion above, putting cleaner in the tank at this stage is like pi$$ing in the ocean. Long term, run it on premium fuel which contains decent additives for sure, but right now it needs a more concentrated treatment. I've done this more times than I can remember with 'troublesome' diesels; it works.TwinKam said:
Just follow my suggestion above, putting cleaner in the tank at this stage is like pi$$ing in the ocean. Long term, run it on premium fuel which contains decent additives for sure, but right now it needs a more concentrated treatment. I've done this more times than I can remember with 'troublesome' diesels; it works.
So drive to the MOT station right after filling the filter housing with system cleaner? Is there any particular one you'd recommend?I did buy Dipetane to put in the tank which I'll do also since I bought it. Tomorrow I'm going to fill with premium diesel and put the Dipetane in and have about 50 miles to do afterwards and maybe some over the weekend. Tomorrow I plan to take the EGR valve off and clean it out, it's got to help?
GreenV8S said:
No they aren't.
You've just listed a bunch of numbers. Probably only from one sensor, but you've left us to guess which one.
If you want any sort of diagnosis, share all the readings. That means CO, HC, Lambda and test description for each test.
Smelly old derv...none of those apply.You've just listed a bunch of numbers. Probably only from one sensor, but you've left us to guess which one.
If you want any sort of diagnosis, share all the readings. That means CO, HC, Lambda and test description for each test.
AntTPIV8 said:
TwinKam said:
Just follow my suggestion above, putting cleaner in the tank at this stage is like pi$$ing in the ocean. Long term, run it on premium fuel which contains decent additives for sure, but right now it needs a more concentrated treatment. I've done this more times than I can remember with 'troublesome' diesels; it works.
So drive to the MOT station right after filling the filter housing with system cleaner? Is there any particular one you'd recommend?I did buy Dipetane to put in the tank which I'll do also since I bought it. Tomorrow I'm going to fill with premium diesel and put the Dipetane in and have about 50 miles to do afterwards and maybe some over the weekend. Tomorrow I plan to take the EGR valve off and clean it out, it's got to help?
There are specific ‘get it through an MOT’ additives available at halfords and such, although I’ve not had reason to use them myself so far.
One more thing, is the car getting up to temperature properly(should be 90 on the gauge), and does the temp gauge read a consistent temperature once it’s got there.
If the thermostat has failed it’ll struggle to burn cleanly, although I’d expect you to have seen poor mpg before now.
If the temp sensor dies they default to some silly low temperature reading and inject extra fuel to keep it running in what the car thinks is bad conditions.
If the thermostat has failed it’ll struggle to burn cleanly, although I’d expect you to have seen poor mpg before now.
If the temp sensor dies they default to some silly low temperature reading and inject extra fuel to keep it running in what the car thinks is bad conditions.
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