Eastcoastdiesel Posted July 31, 2013 Share Posted July 31, 2013 I am sorry for posting frantically, but I need some help. We have two trucks ( mack vision 2006 cxn613) in our fleet that are just being real nasty. Turbo acuator is dumping all air, boost pressure is lost until about 3rd gear. Once you hit 3rd gear boost is fine. No air to air leaks, turbo is in working order. There is an air purging sound from the valve that is aired by the pid filter. Please help, if you need a video of the noise, I can text, but my phone is being shoddy. Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/ Share on other sites More sharing options...
thomastractorsvc Posted July 31, 2013 Share Posted July 31, 2013 What codes is it showing? Have all the lines and everything been checked? Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-196959 Share on other sites More sharing options...
Eastcoastdiesel Posted July 31, 2013 Author Share Posted July 31, 2013 No codes even on the prolink iq scanner. Lines have been checked. Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-196963 Share on other sites More sharing options...
lucerne tractor Posted July 31, 2013 Share Posted July 31, 2013 I'd like to hear more on this and the outcome. I have the same model and am not happy with the boost. At times it seems to pull fine then other times? . New air to air, new vgt sensor and complete new vgt oil filter system. Sometimes only 25 to 26lbs when pulling hard, other times 30. Shouldn't it be 35 lbs? Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-196964 Share on other sites More sharing options...
lucerne tractor Posted July 31, 2013 Share Posted July 31, 2013 Maybe the new member Katie has seen this, it sounds like the odds are good since these are the trucks she works on. Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-196965 Share on other sites More sharing options...
Eastcoastdiesel Posted July 31, 2013 Author Share Posted July 31, 2013 I'll get a pic outta my spec book but have you tried changing the bap sensor? That's cured a few boost problems for me.Here's a video of whats happening to mine. You think it could be the ECM?http://i197.photobucket.com/albums/aa111/outdooritis/B9EA833A-54A9-4BE8-A3E6-F7859CD5C35B-431-000001998F4BD77D.mp4Sorry crappy phone video 1 Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-197034 Share on other sites More sharing options...
Eastcoastdiesel Posted August 1, 2013 Author Share Posted August 1, 2013 Nobody Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-197211 Share on other sites More sharing options...
thomastractorsvc Posted August 1, 2013 Share Posted August 1, 2013 If its not throwing codes may be weak, dirty or hanging springs in a solenoid. BTW what type of turbo is it?, the one that has variable pitch blades? If so could be that hanging up. Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-197245 Share on other sites More sharing options...
lucerne tractor Posted August 2, 2013 Share Posted August 2, 2013 I'll get a pic outta my spec book but have you tried changing the bap sensor? That's cured a few boost problems for me.Here's a video of whats happening to mine. You think it could be the ECM?http://i197.photobucket.com/albums/aa111/outdooritis/B9EA833A-54A9-4BE8-A3E6-F7859CD5C35B-431-000001998F4BD77D.mp4Sorry crappy phone videoBAP sensor, where is it, what does it do, what am I looking for? thanks Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-197428 Share on other sites More sharing options...
lucerne tractor Posted August 2, 2013 Share Posted August 2, 2013 Watched the video, mine bleeds out constant when the pressure is down to 0 and pumping up, once it closes it pumps up air, this is behind tons of airlines on the drivers side above the steering column correct? I can't really see mine, but I can see the rubber disk and feel the air. It pumps up so slow that it sets off a vgt code. Once it reaches pressure the code goes off. Maybe mine is bleeding like your at pressure, will have to check. That is the treadle valve correct? I just changed the vgt sensor so I know it's not that. Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-197430 Share on other sites More sharing options...
mrgumby Posted August 21, 2013 Share Posted August 21, 2013 check the VTG actuator could be screwing up off and on thats what mine was doing sometimes it would hold and sometimes it wouldn't Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-200980 Share on other sites More sharing options...
turckster Posted August 23, 2013 Share Posted August 23, 2013 First thing I would check is make sure all grounds are ok and batteries and connections are good. I know that sounds goofy but bad ground and batteries do strange things. Check eecu pins and connectors for damage or corrosion. It Could be that the eecu needs to be flashed and reprogramed. Was the boost pressure sensor recently replaced? If so, could be the wrong sensor. The AI engine and AC engine both have sensors that look the same but do not interchange. Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-201345 Share on other sites More sharing options...
staxx Posted August 24, 2013 Share Posted August 24, 2013 The VGT controller is leaking air psi out the exhaust port = VGT controller no good replace. Need to check the intake over boost check valve also ,if you follow the steel line that comes off the turbo down pipe to were in connects to the manifold the fitting at intake there is a check valve and controls turbo boost surge. Sometimes the spring breaks inside, remove the fitting and inspect for broken spring. If its not broken you can run the end cap jam nut up to increase tension on valve. You said no codes but the wire connection at the turbo that has spring clip on it is notorious for cause low power low boost surge and 45 code . The pins get loose in connection because fan blows on it causing it to vibrate causing pins in connection to get loose . The pins are replaceable so this is a easy fix . The VGT controller use to be rebuildable not sure if you can still get soliniod for it. Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-201491 Share on other sites More sharing options...
Andriy Posted September 19, 2015 Share Posted September 19, 2015 I'll get a pic outta my spec book but have you tried changing the bap sensor? That's cured a few boost problems for me.Here's a video of whats happening to mine. You think it could be the ECM?http://i197.photobucket.com/albums/aa111/outdooritis/B9EA833A-54A9-4BE8-A3E6-F7859CD5C35B-431-000001998F4BD77D.mp4Sorry crappy phone videoHello. I have exact same issue with my truck mack vision 2007 cxn613. Would you please share if you resolved the issue. Thank you Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-304432 Share on other sites More sharing options...
Andriy Posted September 19, 2015 Share Posted September 19, 2015 I'll get a pic outta my spec book but have you tried changing the bap sensor? That's cured a few boost problems for me.Here's a video of whats happening to mine. You think it could be the ECM?http://i197.photobucket.com/albums/aa111/outdooritis/B9EA833A-54A9-4BE8-A3E6-F7859CD5C35B-431-000001998F4BD77D.mp4Sorry crappy phone videoHello. I have the same issue with my truck mack vision 2007 cxn613. Would you please share if you resolved the issue. Thank you Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-304434 Share on other sites More sharing options...
Ron8426 Posted May 12, 2020 Share Posted May 12, 2020 I have the same Mack vision and very similar problem. Truck runs great but vgt valve leaking air and turbo actuator is sounds like a vacuum is on. Need help Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-451052 Share on other sites More sharing options...
Dirtworks Posted January 23, 2022 Share Posted January 23, 2022 Has anyone figured out what is was bc my 07 chn 460 turbo dumps all boost when i have to come to a quick stop and doesnt build till almost 3rd gear also Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487788 Share on other sites More sharing options...
fjh Posted January 25, 2022 Share Posted January 25, 2022 (edited) Not saying this is the problem however these engines are or should be equip with an over boost valve and tube ! That valve may be sticking open! Its the 1 inch tube on the back of the intake horn on the engine the tube attaches to the exhaust pipe! this valve is apparently set to lift off at 25 psi if it is sticking this could cause an intermittent boost scenario. see stax comment Edited January 25, 2022 by fjh 1 Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487891 Share on other sites More sharing options...
Joey Mack Posted January 25, 2022 Share Posted January 25, 2022 yep The ASET CEGR series has that valve, I had replace one a few months ago, because it was sprung inside. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487893 Share on other sites More sharing options...
fjh Posted January 25, 2022 Share Posted January 25, 2022 48 minutes ago, Joey Mack said: yep The ASET CEGR series has that valve, I had replace one a few months ago, because it was sprung inside. jojo jojo we built a setup for boost checking these engine two flat plates capping the exhaust and the inlet ! We also had to plug this valve off after testing it to see where it was blowing off at.remove it and put a pipe plug in its place then pressure up the exhaust and intake system to check it all for leaks this test was ultimate for leak checking Absolute coverage as far as leaks went!You can even check the turbo drain tube for blow by which was a fairly common issue on these and some AI turbos! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487894 Share on other sites More sharing options...
Vladislav Posted January 25, 2022 Share Posted January 25, 2022 4 hours ago, fjh said: jojo we built a setup for boost checking these engine two flat plates capping the exhaust and the inlet ! We also had to plug this valve off after testing it to see where it was blowing off at.remove it and put a pipe plug in its place then pressure up the exhaust and intake system to check it all for leaks this test was ultimate for leak checking Absolute coverage as far as leaks went!You can even check the turbo drain tube for blow by which was a fairly common issue on these and some AI turbos! What grade of pressure do you apply? Something about the normal boos figures? Or higher? Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487905 Share on other sites More sharing options...
fjh Posted January 25, 2022 Share Posted January 25, 2022 4 minutes ago, Vladislav said: What grade of pressure do you apply? Something about the normal boos figures? Or higher? yup any thing up to 40 psi depending on what your looking for! Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487906 Share on other sites More sharing options...
Vladislav Posted January 25, 2022 Share Posted January 25, 2022 8 minutes ago, fjh said: yup any thing up to 40 psi depending on what your looking for! Thanks. I'm looking for everything since have nothing ready Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487907 Share on other sites More sharing options...
Joey Mack Posted January 25, 2022 Share Posted January 25, 2022 'F' It's got to be great that you work in a shop that lets you make tool's. The last Mack dealership I worked in, had no interest in my tool making ability... It had to be a "MackVo" approved tool.. I still made tools when no-one was looking, and fixed what I could... One boost issue that I solved after a bunch of test drives and head scratching, was on an ASET 'C' eng.. The boost sensor that was replaced was the wrong part number for that engine and it would dump boost at 1500 RPM's consistently.. 2 guys worked on this truck for a month, and put aa turbo on it and an EECU, and all kinds of hours of labor, I was watching but didn't really know all the details.. So I removed the boost sensor, and found a chart that showed the different voltage values for sensors for the ASET 'C'.. I discovered that the sensor that was correct, used 1.5 volts more than the in-correct sensor, causing the EECU to open the VGT early.. $65.00 part, that cost over $8000.00 to find, this was in 2008... I'm just posting my experience. Jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487917 Share on other sites More sharing options...
fjh Posted January 26, 2022 Share Posted January 26, 2022 14 hours ago, Joey Mack said: 'F' It's got to be great that you work in a shop that lets you make tool's. The last Mack dealership I worked in, had no interest in my tool making ability... It had to be a "MackVo" approved tool.. I still made tools when no-one was looking, and fixed what I could... One boost issue that I solved after a bunch of test drives and head scratching, was on an ASET 'C' eng.. The boost sensor that was replaced was the wrong part number for that engine and it would dump boost at 1500 RPM's consistently.. 2 guys worked on this truck for a month, and put aa turbo on it and an EECU, and all kinds of hours of labor, I was watching but didn't really know all the details.. So I removed the boost sensor, and found a chart that showed the different voltage values for sensors for the ASET 'C'.. I discovered that the sensor that was correct, used 1.5 volts more than the in-correct sensor, causing the EECU to open the VGT early.. $65.00 part, that cost over $8000.00 to find, this was in 2008... I'm just posting my experience. Jojo Bro this happend's lots at our place too! Difference thou is we don't got a tool budget if its something we run across we need we will build it if the tool looks to overly priced by the volvo /mack criminals! There are also things you can do on MP engines to find leaks that are NOT In the manual ! On an MP8 if you you got a squeal/ leak simply force a regen on it ,this will usually build enough pressure on the exhaust and intake side once its making the noise, run warm water over the manifold/turbo and egr cooler plumbing joints this usually will uncover what your looking for as a sound change when the water hits the effected area! Just shit you learn over the years you know how it goes!And usually its the school of hard Knocks that you learn from ! The above MP8 story there was learned late on a Saturday afternoon at going home time after a EGR Cooler change! 😡 1 Quote Link to comment https://www.bigmacktrucks.com/topic/32136-please-help-boost-dump/#findComment-487946 Share on other sites More sharing options...
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