MOT test passed.

[tonyldee]

Battled over the years , especially the last few of the 17 years I have owned my 3litre, auto 960. I think today may have sealed her fate. With readings of 0.49% against limit of 0.20% on CO and 205ppm against limit of 200 and 0.49% compared to 0.30% on CO at natural idle test, I was informed that ,as there was a slight showing of blue smoke which was more obvious on blipping the throttle, then a fail was compulsory as NO blue smoke allowed.
It seems so unfair to penalise what appears to be a minor infringement- I have not noticed it! Yet there are diesel taxis and, in particular, buses, belching out clouds of noxious smoke that obscure vision in some cases, choking you at best! My local garage has advised that, although there are options that can be tried, it could be an expense that cannot be justified. Even a replacement engine could not guarantee success.
Any thoughts, guys?

[Laird Scooby]

Originally Posted by tonyldee

Battled over the years , especially the last few of the 17 years I have owned my 3litre, auto 960. I think today may have sealed her fate. With readings of 0.49% against limit of 0.20% on CO and 205ppm against limit of 200 and 0.49% compared to 0.30% on CO at natural idle test, I was informed that ,as there was a slight showing of blue smoke which was more obvious on blipping the throttle, then a fail was compulsory as NO blue smoke allowed.
It seems so unfair to penalise what appears to be a minor infringement- I have not noticed it! Yet there are diesel taxis and, in particular, buses, belching out clouds of noxious smoke that obscure vision in some cases, choking you at best! My local garage has advised that, although there are options that can be tried, it could be an expense that cannot be justified. Even a replacement engine could not guarantee success.
Any thoughts, guys?

What year is your 960? There are many early cars that won't even pass the standard cat test (and where a puff of smoke of any colour is acceptable), never mind the later cat test with the tighter emissions.
I've got a few ideas in mind but a few questions first, when was the oil and filter last changed, who by and what oil was used?

[Bob Meadows]

Yes and as above:~ prior to the MOT I would always give the car an oil & filter change- just before it goes in give it a good faster run than normal, you can now purchase a no smoke engine oil or additive. These may be worth trying as part of the solution- I would think that the car could live on if the problem is found etc.
Good Luck.

[rwdkev]

Hi Tony,

Did you see this.....?

https://www.volvoforums.org.uk/showthread.php?t=300477


Kev

[rwdkev]

Originally Posted by Laird Scooby

What year is your 960?

It's 1993

[Laird Scooby]

Originally Posted by rwdkev

It's 1993

That falls into the 0.3%CO and 1200ppm/HC then Kev so shouldn't have failed on the HC and possibly if the cat had a decent warm up, wouldn't have failed on the CO either. Also it should (if memory serves) be allowed a minor puff of smoke when revving it, i'll have to try and find the link later to the Goernment website with the limits on. Also being a 1993, possibly earlier (depenidng whether it had sat in a dealers for a while before being registered or not) it may only need to pass the BET which is 3.5%CO and 1200ppm/HC so all is not lost yet!

[tonyldee]

Thanks, Kev. Yes a 1993 (August) Oil & filter changed 4,000 ago. Had a carbon clean done in the summer plus took car for an 80 mile run on the motorway so that the cat. was hot for the mot arriving within 10 mins. of appointed time. Also ran a bottle of Forte petrol injector fluid through the system. I was so confident I had done everything right, I had invested in a new pair of tyres the previous week as the two front were showing signs of "feathering" on the outer edges. Didn't want any excuses! Damn!

[tonyldee]

Limits set at 0.20%, achieved 0.49 and 0.50% at 2500-3000 rpm on CO
HC limit shown as 200ppm, achieved 205 and 231 respectively on the two tests.
Lambda set at 0.97-1.03, achieved 1.045
On the Natural Idle Test limit on CO 0.30% mine was 0.49%
Would be very interested if you could come up with any conflicting settings!

[Laird Scooby]

Originally Posted by tonyldee

Thanks, Kev. Yes a 1993 (August) Oil & filter changed 4,000 ago. Had a carbon clean done in the summer plus took car for an 80 mile run on the motorway so that the cat. was hot for the mot arriving within 10 mins. of appointed time. Also ran a bottle of Forte petrol injector fluid through the system. I was so confident I had done everything right, I had invested in a new pair of tyres the previous week as the two front were showing signs of "feathering" on the outer edges. Didn't want any excuses! Damn!

Originally Posted by tonyldee

Limits set at 0.20%, achieved 0.49 and 0.50% at 2500-3000 rpm on CO
HC limit shown as 200ppm, achieved 205 and 231 respectively on the two tests.
Lambda set at 0.97-1.03, achieved 1.045
On the Natural Idle Test limit on CO 0.30% mine was 0.49%
Would be very interested if you could come up with any conflicting settings!

Oil/filter changed 4000 miles ago but how long ago? Also by whom and what oil was used?

The tester used the wrong test parameters, yours should be at least 0.3%CO and 1200ppm/HC, possibly eligible for the BET test of 3.5%CO and 1200ppm/HC

Lambda value says it's running rich though. When was the air filter last changed and also how old is the Lambda sensor?

[tonyldee]

Oil changed at last MoT using synthetic. Air filter approx. 1000 miles. Checked Government "transition period" for the 1993 and she still failed those marginal differences. Comment from testing station was basically "BLUE SMOKE IS AN INSTANT FAIL" Lambda sensor changed Dec. 2016

Heartbreaking but just how much do you keep throwing at the problem when the outcome is uncertain? Worn tyres, joints, blowing exhausts are all curable but when a motor runs sweet but the guy with the whip hand says NO, I feel that sadly it is time to let go. I would hate to think that she is to be crushed. I hope I can find a sympathetic breaker who can pas on so many good bits to fellow enthusiasts.