Passed the smoke test - relief!

rovertone · 13th February 2018, 16:06

Total relief today when my MOT tester said you have passed the MOT including a normal smoke test. Usually I only get a pass with a very 'gentle' test to get a low enough reading.

Some of you may have read my various posts trying to resolve this issue over a long time .Having noticed a very slight oil mist near one of the inlet ports I decided to change all the seals. This must have been the culprit, I still have smoke but it is more a 'dirty' haze rather than rich black so I am assuming that this is the crud blowing from the exhaust from my pootling about town.

Way back I noticed a similar oil mist when I removed the manifold for cleaning but didn't really give it a thought just cleaned the seals and put 'em back, so there's a lesson learnt!
Hope this may help anyone else who is struggling with a similar problem having tried all the usual points.

bl52krz · 14th February 2018, 11:06

Before I take my cdt for its mot, I give it an ‘Italian Tuneup’. I take it onto the country road 200 yards from where I live, and with no one about, second gear and take it up to 4000-4500 rpm for about 600 yards, or metres if you like. I then go round the block, and coming back the other way, do the same again. On the second run, you only get the smallest amount of sh** come out the exhaust for a few seconds. It then flies through the mot. I also put Redex Injector Cleaner in the tank. What was your smoke test result? [/COLOR][/B]

rovertone · 14th February 2018, 16:35

I do exactly the same with redex and did about 5 miles on dual carriageway at 4000rpm.
Didn't get the reading, my garage know the history of me trying to sort the problem and the owners first retort was 'your smoke test was no problem, what have you done?', I was so pleased never give the actual result a thought!

If this hadn't worked my next plan was to renew the exhaust, well at least the cat, I am sure that I read somewhere that if a diesel has done most of its mileage pootling about the cat can soot up so badly that partial blockage causes back pressure that slows the turbo response on hard acceleration hence the over fueling. That may of course be totally unfounded and 'clutching of straws' on my part. Anyway the added good news is the original exhaust system will live on for a bit longer.

bl52krz · 14th February 2018, 18:29

My opacity reading was 0.01. 1.5 on ‘fast pass’ is the limit.

Richard1973 · 15th February 2018, 16:19

I found cleaning the area around the MAP sensor inside the manifold made a big difference to mine.

13th February 2018, 16:06	#1
rovertone Gets stuck in Rover 75 Conne SE Auto CDTi Join Date: Nov 2012 Location: Redditch Posts: 676 Thanks: 185 Thanked 135 Times in 109 Posts	Passed the smoke test - relief! Total relief today when my MOT tester said you have passed the MOT including a normal smoke test. Usually I only get a pass with a very 'gentle' test to get a low enough reading. Some of you may have read my various posts trying to resolve this issue over a long time .Having noticed a very slight oil mist near one of the inlet ports I decided to change all the seals. This must have been the culprit, I still have smoke but it is more a 'dirty' haze rather than rich black so I am assuming that this is the crud blowing from the exhaust from my pootling about town. Way back I noticed a similar oil mist when I removed the manifold for cleaning but didn't really give it a thought just cleaned the seals and put 'em back, so there's a lesson learnt! Hope this may help anyone else who is struggling with a similar problem having tried all the usual points. __________________ 2003 Mk 1 Connie SE CDTi Auto Monogram Mirage 2/Sandstone Leather 511th CDTi out of 4744 produced 9th in Mirage 2 out of 17 produced Also 2004 Rover 25 SXi CVT, 1999 Megane Cabriolet and still missing my 800 Fastback.

14th February 2018, 11:06	#2
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,444 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	Before I take my cdt for its mot, I give it an ‘Italian Tuneup’. I take it onto the country road 200 yards from where I live, and with no one about, second gear and take it up to 4000-4500 rpm for about 600 yards, or metres if you like. I then go round the block, and coming back the other way, do the same again. On the second run, you only get the smallest amount of sh** come out the exhaust for a few seconds. It then flies through the mot. I also put Redex Injector Cleaner in the tank. What was your smoke test result? [/COLOR][/B] __________________ Great Barr, Birmingham. Last edited by bl52krz; 14th February 2018 at 11:09.. Reason: Forgot to add about the Redex

14th February 2018, 16:35	#3
rovertone Gets stuck in Rover 75 Conne SE Auto CDTi Join Date: Nov 2012 Location: Redditch Posts: 676 Thanks: 185 Thanked 135 Times in 109 Posts	I do exactly the same with redex and did about 5 miles on dual carriageway at 4000rpm. Didn't get the reading, my garage know the history of me trying to sort the problem and the owners first retort was 'your smoke test was no problem, what have you done?', I was so pleased never give the actual result a thought! If this hadn't worked my next plan was to renew the exhaust, well at least the cat, I am sure that I read somewhere that if a diesel has done most of its mileage pootling about the cat can soot up so badly that partial blockage causes back pressure that slows the turbo response on hard acceleration hence the over fueling. That may of course be totally unfounded and 'clutching of straws' on my part. Anyway the added good news is the original exhaust system will live on for a bit longer. __________________ 2003 Mk 1 Connie SE CDTi Auto Monogram Mirage 2/Sandstone Leather 511th CDTi out of 4744 produced 9th in Mirage 2 out of 17 produced Also 2004 Rover 25 SXi CVT, 1999 Megane Cabriolet and still missing my 800 Fastback.

14th February 2018, 18:29	#4
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,444 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	My opacity reading was 0.01. 1.5 on ‘fast pass’ is the limit. __________________ Great Barr, Birmingham.

15th February 2018, 16:19	#5
Richard1973 Loves to post Rover 75 Saloon CDTi Join Date: Aug 2012 Location: Mansfield Posts: 287 Thanks: 18 Thanked 69 Times in 52 Posts	I found cleaning the area around the MAP sensor inside the manifold made a big difference to mine.