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C220 CDi Emissions failure - Is it time to say goodbye?

Oxfordian

Active Member
Joined
Mar 3, 2014
Messages
107
Location
Warwickshire (was Oxfordshire)
Car
C220 CDI Sports Coupe
A few days ago, my C220 CDi Sports Coupe failed its MOT on a few things, including its emissions - Exhaust emissions exceed manufacturer's specified limit [8.2.2.2(a)]. But note that there was only an advisory for 'Exhaust emits excessive smoke ... etc .' as not likely to obscure the vision of other road users.

I bought the car new in March 2002 and in its 22 years, it's been reliable & served me well. Obviously there have been issues, some of which were the result of poor work by technicians. Its now done 272,000 miles, is a little noisy but accelerates really well, returns 55+ mpg on a long run, and has not been costing too much to maintain (which is why I've kept it on).

One of the individuals I've consulted following the failure, thought it only just failed the emissions test, another thought the DPF was damaged. I do understand that if it is damaged, then owing to the age of the car and its mileage, its uneconomic to rectify it, so effectively game over :(

Questions:
Is there any way of positively identifying a damaged DPF, short of physically dismantling it?
If it is not damaged, is there anything to be done that might reduce the emissions?

Thanks for any suggestions - even if it's to move on!
 
A few days ago, my C220 CDi Sports Coupe failed its MOT on a few things, including its emissions - Exhaust emissions exceed manufacturer's specified limit [8.2.2.2(a)]. But note that there was only an advisory for 'Exhaust emits excessive smoke ... etc .' as not likely to obscure the vision of other road users.

I bought the car new in March 2002 and in its 22 years, it's been reliable & served me well. Obviously there have been issues, some of which were the result of poor work by technicians. Its now done 272,000 miles, is a little noisy but accelerates really well, returns 55+ mpg on a long run, and has not been costing too much to maintain (which is why I've kept it on).

One of the individuals I've consulted following the failure, thought it only just failed the emissions test, another thought the DPF was damaged. I do understand that if it is damaged, then owing to the age of the car and its mileage, its uneconomic to rectify it, so effectively game over :(

Questions:
Is there any way of positively identifying a damaged DPF, short of physically dismantling it?
If it is not damaged, is there anything to be done that might reduce the emissions?

Thanks for any suggestions - even if it's to move on!
Would a 2002 220cdi have DPF??
 
WOW:oops: I just took the word of the technician where the MOT was done.

How do I find an answer to that thunderbolt of yours?
I'm no expert - I'm sure someone more knowledgeable will be along shortly - but none of the diesels I had from that period had particulate filters. Cats, yes, filters no.
 
I had a 2004 C220 CDI with a DPF, it was an option in that year, I can't say about earlier years.
I would go underside and look for a silencer type box that has wired sensors in it. If yes then you have a DPF.

Don't confuse that with the Cat that is close to the engine, that will have the 1 temperature sensor in it.
The DPF, if fitted, would be below the drivers seat and have 2 pressure pipes, back to the dp switch, and a temp sensor.

Either way I would be thinking of some fuel additive to clean the system, and a damn good thrashing (not Basil Fawlty style) prior to another emissions test.
 
I had a 2004 C220 CDI with a DPF, it was an option in that year, I can't say about earlier years.
I would go underside and look for a silencer type box that has wired sensors in it. If yes then you have a DPF.

Don't confuse that with the Cat that is close to the engine, that will have the 1 temperature sensor in it.
The DPF, if fitted, would be below the drivers seat and have 2 pressure pipes, back to the dp switch, and a temp sensor.

Either way I would be thinking of some fuel additive to clean the system, and a damn good thrashing (not Basil Fawlty style) prior to another emissions test.
The good old "Italian Tune Up".
👍
Certainly worth a go, especially if the emissions fail was only marginal.
 
A few days ago, my C220 CDi Sports Coupe failed its MOT on a few things, including its emissions - Exhaust emissions exceed manufacturer's specified limit [8.2.2.2(a)]. But note that there was only an advisory for 'Exhaust emits excessive smoke ... etc .' as not likely to obscure the vision of other road users.

I bought the car new in March 2002 and in its 22 years, it's been reliable & served me well. Obviously there have been issues, some of which were the result of poor work by technicians. Its now done 272,000 miles, is a little noisy but accelerates really well, returns 55+ mpg on a long run, and has not been costing too much to maintain (which is why I've kept it on).

One of the individuals I've consulted following the failure, thought it only just failed the emissions test, another thought the DPF was damaged. I do understand that if it is damaged, then owing to the age of the car and its mileage, its uneconomic to rectify it, so effectively game over :(

Questions:
Is there any way of positively identifying a damaged DPF, short of physically dismantling it?
If it is not damaged, is there anything to be done that might reduce the emissions?

Thanks for any suggestions - even if it's to move on!
Tks to SpikeyMikey for pointing out the DPF error. A bit of searching confirms that I was misinformed and the individuals certainly meant catalytic converter, not DPF.

So my questions should be:
Is it possible to check if a catalytic converter is blocked or damaged?
If blocked, can it be cleaned?
If damaged, can it be replaced at a reasonable cost? I see Auto Doc (whoever they are) are quoting £ 204,85 + vat for the item, but I don't know if this is a 1, 2 or 3+ hour job.

Any advice welcomed!
 
If it's blocked, even partially, I would expect the power to be down.
Assuming the injectors are still original then they have done a lot of work.
So has the EGR.
As a worn engine it might be passing oil, how does the oil level hold up between services.

Spending a few quids to try and run it for a bit longer 'aint daft. Spending larger sums is really a judgement call. How much would you be spending on the replacement? How reliable would that be?
Clearly the value of the car isn't much, but how much the car is worth to you is more relevant.
But how much are you likely to spend as time rolls on?

I've run one of these engines to 335k miles, and then sold it on to a happy buyer. So it's likely still got good legs for the future.
 
I had a 2004 C220 CDI with a DPF, it was an option in that year, I can't say about earlier years.
I would go underside and look for a silencer type box that has wired sensors in it. If yes then you have a DPF.

Don't confuse that with the Cat that is close to the engine, that will have the 1 temperature sensor in it.
The DPF, if fitted, would be below the drivers seat and have 2 pressure pipes, back to the dp switch, and a temp sensor.

Either way I would be thinking of some fuel additive to clean the system, and a damn good thrashing (not Basil Fawlty style) prior to another emissions test.
Re: Fuel additive. I came across this amusing post which may be BS!

"Back in the early 80's while working as a mechanic, my boss did an experiment. We pulled heads off a daily driver and inspected the carbon build up. We put the engine back together and ran it up to temp. He then slowly poured cold water down the carb at about 3500 rpm. He poured about a cup, maybe more (I don't remember, its been a while). At the end of the day when the engine was cool enough, we pulled the heads off, most of the carbon deposits were gone."
 
If it's blocked, even partially, I would expect the power to be down.
Assuming the injectors are still original then they have done a lot of work.
So has the EGR.
As a worn engine it might be passing oil, how does the oil level hold up between services.

Spending a few quids to try and run it for a bit longer 'aint daft. Spending larger sums is really a judgement call. How much would you be spending on the replacement? How reliable would that be?
Clearly the value of the car isn't much, but how much the car is worth to you is more relevant.
But how much are you likely to spend as time rolls on?

I've run one of these engines to 335k miles, and then sold it on to a happy buyer. So it's likely still got good legs for the future.
Hi m80

1. Power doesn't seem to be down too much, considering it's done 270k. Last year I was a bit naughty in speeding & quickly got back down from just under 120mph with more to go. Also 55+mph on long runs, though in stop-start traffic economy is not as good as it used to be.

2. One injector was replaced years ago & all of them had to be 'cleaned'.

3. Re the EGR. I've not had any engine warnings.

4. Oil is holding up well in between services & I've only had to put in a litre in the last 6 months.

The points you've set out after, are all things I've been considering, but I was so shocked at the emission MOT failure that it's taken a few days to be rational about the next steps, the first of which was to seek advice from you all.

One further point on the MOT Smoke Test
I've looked back on a successful 2021 MOT emission test, to see that the MOT Smoke Test used "Fast Pass" with 'No Manufacturer's plate visible', whereas my recent test used Plated Value. As MOT emission rules changed in 2018, I'm struggling to get my head round the move from "Fast Pass" in 2021 to "Plated Value" now:oops:

With only a 16 day window remaining I don't have a lot of time to get it sorted!

Tks
 
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I don't when it started but manufacturers now put an emissions value in a square box, within the VIN plate. That's to gain better taxation if the plate figure is low.
Then at MOT the vehicle needs meet that value.

If the tester can't find the plate value, or the value can't be read, then the tester uses the national default value.
The default varies depending on vehicle age, yours will be at 1.5 thingies, but more likely 3 of 'em as a default.

What are your progressive figures at MOTs?
 
Hi m80

1. Power doesn't seem to be down too much, considering it's done 270k. Last year I was a bit naughty in speeding & quickly got back down from just under 120mph with more to go. Also 55+mph on long runs, though in stop-start traffic economy is not as good as it used to be.

2. One injector was replaced years ago & all of them had to be 'cleaned'.

3. Re the EGR. I've not had any engine warnings.

4. Oil is holding up well in between services & I've only had to put in a litre in the last 6 months.

The points you've set out after, are all things I've been considering, but I was so shocked at the emission MOT failure that it's taken a few days to be rational about the next steps, the first of which was to seek advice from you all.

One further point on the MOT Smoke Test
I've looked back on a successful 2021 MOT emission test, to see that the MOT Smoke Test used "Fast Pass" with 'No Manufacturer's plate visible', whereas my recent test used Plated Value. As MOT emission rules changed in 2018, I'm struggling to get my head round the move from "Fast Pass" in 2021 to "Plated Value" now:oops:

With only a 16 day window remaining I don't have a lot of time to get it sorted!

Tks
Try some Archoil 6400-d from eBay for £24 and an Italian tune up
 
Our Sons 1.4 TDCI Fiesta was a very similar situation. It had 176k on it and was his transport to Uni. My other half had heard about 2 stroke oil being added to the diesel. There plenty of for and against the continuous use of it on the various forums. However as a one off application (if you have issues) there's something to be said. He found out the ratio of 200:1 and mineral FB spec and filled his car up. Now it did sound quieter and early on after mixing it there was a cloud of smoke. Once this had passed the car was definitely quieter and subsequently passed its MOT with flying colours. It's not for everyone but give it some thought........
 
I don't when it started but manufacturers now put an emissions value in a square box, within the VIN plate. That's to gain better taxation if the plate figure is low.
Then at MOT the vehicle needs meet that value.

If the tester can't find the plate value, or the value can't be read, then the tester uses the national default value.
The default varies depending on vehicle age, yours will be at 1.5 thingies, but more likely 3 of 'em as a default.

What are your progressive figures at MOTs?
Sadly, I've misfiled my previous 2 years MOT certificates but as well as last week's test, I located one from 2021.

2024
2021
MOT Smoke TestPlated ValueMax LimitsFast PassMax Limits
Smoke ReadingPeak 1
1.16​
0.00​
Peak 2
1.39​
Peak 3
1.10​
Peak 4
1.19​
Peak 5
1.20​
Peak 6
1.32​
Zero Drift
0.04​
Pass
0.10​
0.00​
Pass
0.10​
Average
1.20​
0.00​
MOT Test Result
1.20​
Fail
0.80​
0.00​
Pass
1.50​
 
So your plate value is 0.8
But if that can't be read then the default used would be 3.

Another test centre might be unable to find the plated value, so at 3.0 any of the readings obtained then the car would pass.
 
So your plate value is 0.8
But if that can't be read then the default used would be 3.

Another test centre might be unable to find the plated value, so at 3.0 any of the readings obtained then the car would pass.
Ok, tks for this really helpful confirmation. I had thought that might be the case, but then decided I was being naïve. I came across an insightful comment that, "achieving the 0.6m-1 value from new might never have been feasible" for many older cars.

Tks to all suggestions, including the fuel additive & a thorough "Basil Fawlty" or should I say "Italian Tune up"🤣
 
Ok, tks for this really helpful confirmation. I had thought that might be the case, but then decided I was being naïve. I came across an insightful comment that, "achieving the 0.6m-1 value from new might never have been feasible" for many older cars.

Tks to all suggestions, including the fuel additive & a thorough "Basil Fawlty" or should I say "Italian Tune up"🤣
Let us know how you get on 🤞
 
Never done an Italian tune up, how will thrashing an engine clean it ?
It wouldn't get any hotter and the fuel pressure through the injectors would not rise to clean the internals, so does it do anything ?
Asking for a friend.
 

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