http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: Revealed: scandal of removed pollution filters in diesel cars en Sun, 31 May 2026 20:12:02 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224304 Tue, 28 Jun 2016 00:38:14 +0000 algo 224304@http://citycyclingedinburgh.info/bbpress/ <p>@steveo - who knows? Certainly not me. This is a cycling forum so I chance my arm on diesel engine related matters having built a few tdi engines and shoehorned them into vehicles that were never designed for them.... </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224298 Tue, 28 Jun 2016 00:00:46 +0000 kaputnik 224298@http://citycyclingedinburgh.info/bbpress/ <p>Thanks for the correction Algo / Steveo. I suppose it's somewhat appropriate that diesels breathe through their a***s ;) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224295 Mon, 27 Jun 2016 23:24:10 +0000 steveo 224295@http://citycyclingedinburgh.info/bbpress/ <p>No idea mate, all I know is the turbo never spooled and thus the engine never really had any power after the first 2.5k rpm. ECU never reported any failures so I presume it just never noticed. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224293 Mon, 27 Jun 2016 23:18:43 +0000 algo 224293@http://citycyclingedinburgh.info/bbpress/ <p>This has been going on for years with catalytic converters - you can get exhaust pipes which look like they have them but they are straight through. A diesel engine does indeed breathe through the exhaust as well as through the intake - too much back pressure from constriction and the turbo will fail to spool. EGR pipes are often blocked off too - technically illegal but unless you inspect the inlet manifold port you'd never know. </p> <p>Disconnecting a turbo is an odd phrase - I presume it means the wastegate actuator was disconnected to deregulate boost (very stupid but an alarming number of folk do it). You can't disconnect a turbo without replumbing the entire induction and exhaust system. VNT turbos spool from around 1500rpm - wastegates a bit later depending on aspect ratio. If you have no power over 2500 rpm then most likely the ECU is putting you in limp mode - if you'd disconnected your wastegate actuator to try and increase boost it'll do that. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224290 Mon, 27 Jun 2016 23:01:37 +0000 steveo 224290@http://citycyclingedinburgh.info/bbpress/ <p><em> Why would you disconnect the turbo?</em></p> <p>Goodness knows. Though the way I drive I still can't tell it's got a turbo, I never rev it high enough. I just assumed it was rubbish over 2.5k rpm, it is that's what the turbo is for apparently. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224274 Mon, 27 Jun 2016 18:48:20 +0000 kaputnik 224274@http://citycyclingedinburgh.info/bbpress/ <p>For those not up on their 1960s vintage British Rail diesels, the former locomotive above is known to enthusiasts as a "Whistler" and the latter as a "Tractor". </p> <p>"Choppers", "Shredders", "Hoovers" and "Screamers" are also available for those that like different engine sounds. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224273 Mon, 27 Jun 2016 18:18:58 +0000 wee folding bike 224273@http://citycyclingedinburgh.info/bbpress/ <p>Why would you disconnect the turbo?</p> <p>I love dropping the windows and listening to mine howl.</p> <p>Sometimes it sounds a bit like one of these:</p> <p><a href="https://en.wikipedia.org/wiki/British_Rail_Class_40" rel="nofollow">https://en.wikipedia.org/wiki/British_Rail_Class_40</a></p> <p>The memsahib has a diesel which sounds more like this:</p> <p><a href="https://en.wikipedia.org/wiki/British_Rail_Class_37" rel="nofollow">https://en.wikipedia.org/wiki/British_Rail_Class_37</a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224250 Mon, 27 Jun 2016 14:57:49 +0000 steveo 224250@http://citycyclingedinburgh.info/bbpress/ <p><em>A car does not aspirate through its exhaust system!<br /> </em></p> <p>No but the cleaner (less obstructed) the exhaust path the better. Race cars have straight through exhausts with no filtration etc partly because they don't have to and partly because it lets the engine work better.</p> <p>Having just had my diesel serviced because it thought it was excessively smoky it turned out the turbo had been disconnected by the previous owner when they serviced the DPF, due to insufficient air flow at higher rpm many of the various filters were coated with coke and soot and the exhaust gas recycler was sealed shut. The MOT was only a few weeks prior to this and despite looking like a 1980's taxi it sailed through (that part). </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224249 Mon, 27 Jun 2016 14:39:22 +0000 kaputnik 224249@http://citycyclingedinburgh.info/bbpress/ <p><em>your car will become more economical as it can breathe a lot easier</em></p> <p>A car does not aspirate through its exhaust system! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224248 Mon, 27 Jun 2016 14:33:16 +0000 LaidBack 224248@http://citycyclingedinburgh.info/bbpress/ <p>Autoclinic say..."that MOT testers only check for the housing." My car owning friends say they are good people and know what they are doing ;-)</p> <p>Think this raises a question of the relationship between garages and said testers?</p> <p>Would SEPA not come down on this? </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224247 Mon, 27 Jun 2016 14:27:23 +0000 Dave 224247@http://citycyclingedinburgh.info/bbpress/ <p>Without a filter, will the car not fail the emissions test part of the MOT? If not, that would seem like a pretty simple way to tackle the problem (change the test conditions to catch cars without a filter). </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=16588#post-224246 Mon, 27 Jun 2016 14:22:58 +0000 LaidBack 224246@http://citycyclingedinburgh.info/bbpress/ <p>Rob Edwards has highlighted a disturbing motor trade practice in Sunday Herald. </p> <p><em>"... this is likely to be a major underestimate of the scale of the problem because DPF removal can be hidden from MOT inspectors. Autoclinic Remaps in Carluke, South Lanarkshire, openly advertises such a service on its website.</p> <p>It promises to remove DPFs “while still retaining the housing for MOT purposes”, pointing out that MOT testers only check for the housing. “When we remove a DPF we cut into the housing to remove the insides before welding the original housing up and leave it in place meaning the vehicle WILL NOT fail the MOT test,” the firm says.</p> <p>On its website Absolute Remaps offers “DPF gutting or removal” in East Kilbride, claiming “your car will become more economical as it can breathe a lot easier.” DPF removals are also offered by Infiniti Remapping at Bellshill, North Lanarkshire and Elite Garage Services in Bathgate, West Lothian."</em></p> <p>These firms should face prosecution. If it's a service they sell then paperwork will be there to back it up. We can also be sure that this 'service' will be known to larger car dealers with powerful lawyers. Papers will be loathe to name these.</p> <p><a href="http://www.heraldscotland.com/news/14580495.Revealed__scandal_of_removed_pollution_filters_in_diesel_cars/" rel="nofollow">http://www.heraldscotland.com/news/14580495.Revealed__scandal_of_removed_pollution_filters_in_diesel_cars/</a> </p>