CISCO Posted March 21, 2017 Share Posted March 21, 2017 I have an 03 6.0 that misses only at idle and the miss will go away as soon as it comes off idle. The truck runs great and has lots of power but it just misses at idle on different cylinders. ficm voltage 48v icp is good. I know i read somewhere where the check valves on the high pressure oil rails would cause the same problem im having but im not sure. I will be installing the check vavles on the hight pressure oil rails tomorrow morning and will post my results. Thanks in advance Quote Link to comment Share on other sites More sharing options...
CISCO Posted March 22, 2017 Author Share Posted March 22, 2017 Well the customer texted me last night and said the truck was running good and that he did not want to replace the check valves on the high pressure oil rail. Has anybody seen the concern as shown in the power balance test? Thank you Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted March 22, 2017 Share Posted March 22, 2017 What does ICP look like while its missing? Quote Link to comment Share on other sites More sharing options...
lmorris Posted March 22, 2017 Share Posted March 22, 2017 First thing that pops into my head is a loose crank trigger wheel. Only because of the pattern not being consistent to a single bank, and always paired with the next in the firing order. 2 high-2 low...etc. The 2003 6L was bad for that. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted March 22, 2017 Share Posted March 22, 2017 I was thinking loose injectors aerating the fuel rail, but it usually is one head, not both, and usually is not so selective to a cylinder. Quote Link to comment Share on other sites More sharing options...
CISCO Posted March 22, 2017 Author Share Posted March 22, 2017 I swapped ficm & pcm still same thing mostly missing on 2,7,5,&6 at idle only and smooths out as soon as you push on the accelerator pedal slightly. I also disconnected the alternator & also disconnected all injectors 1 by 1 and still same thing. I did notice that when i cancelled cylinder #4 it did not make a difference and as seen on the power balance test. i also performed relative compression test and it passed. Thank you My number is 816-730-2609 you can call me or text me. Quote Link to comment Share on other sites More sharing options...
CISCO Posted March 24, 2017 Author Share Posted March 24, 2017 Well the customer texted me yesterday and said that he found the problem and when i asked what it was he said that it was the Dual Mass Flywheel. I never asked him how he found out that it was the Dual Mass Flywheel but it makes perfect sense to me. Thank you all 1 Quote Link to comment Share on other sites More sharing options...
lmorris Posted March 24, 2017 Share Posted March 24, 2017 Well the customer texted me yesterday and said that he found the problem and when i asked what it was he said that it was the Dual Mass Flywheel. I never asked him how he found out that it was the Dual Mass Flywheel but it makes perfect sense to me. Thank you all Geez....Keep forgetting they put 6 speeds behind the 6L. Mainly because I never see any. Never heard of dual mass flywheel issues on a 6L either. For future reference, at idle when they are "running rough" you can usually here a very odd noise at the same time. Hard to describe it though. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted March 24, 2017 Share Posted March 24, 2017 A lot of the younger guys have no idea what a problem those DMF were and how they make an idling engine shake like a 3-lb chihuahua shaking and pissing itself. And I can't believe I correctly spelled chihuahua! Quote Link to comment Share on other sites More sharing options...
mchan68 Posted March 24, 2017 Share Posted March 24, 2017 Only makes me wonder why they bother putting dual mass flywheels into vehicles in the first place. I've replaced way more than my share of them, when they were used in the old body style 7.3 trucks. We just replaced one yesterday on a V6 Mustang for a vibration at idle. Quote Link to comment Share on other sites More sharing options...
8WA Sman Posted March 27, 2017 Share Posted March 27, 2017 Wasn't the diag for a bad DMF something like brake torquing???? All I know is be careful on the really bad ones, tech I used to work with broke the bell housing on a ZF doing this. Quote Link to comment Share on other sites More sharing options...
forddieseldoctor Posted March 27, 2017 Share Posted March 27, 2017 But no where in any of the posts talking about the problem was it ever mentioned that it was a manual trans. And since they are so few and far between no one here even gave it a thought. Quote Link to comment Share on other sites More sharing options...
sneakypete Posted March 27, 2017 Share Posted March 27, 2017 saw a lot of failures in the first generation dmax's but a rarity in a powerstroke. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted March 27, 2017 Share Posted March 27, 2017 The DMF was used in '94-97 7.3s and had a very high failure rate- vibration at idle, noise, broken bellhousings, etc. Update was a flat flywheel setup from Luk (and others) that worked really well. Did lots of them in the day, but that was a long time ago. Luk had an engineering facility 2 miles from our shop so we did a lot of prototypes, custom discs and other neat stuff for them. 1 Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted March 27, 2017 Share Posted March 27, 2017 As far as I know only the 03-04 6.0 pickups ever came with a dual mass flywheel. I've never seen one or any symptoms caused by it Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted March 27, 2017 Share Posted March 27, 2017 As far as I know only the 03-04 6.0 pickups ever came with a dual mass flywheel. I've never seen one or any symptoms caused by it Right, and only in the 250/350, for some reason they put flat flywheels in the 450/550. Ford put flat flywheels in when they had issues with them. Quote Link to comment Share on other sites More sharing options...
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