Turker Posted January 19, 2016 Share Posted January 19, 2016 (edited) HEY friends,I took in my truck to Mack dealer for PM, before the PM it was Idling fine after PM It is Idling really rough and not more than 500RPM.under load it runs fine. Before I left the dealer I didn't realize the problem. Any help? ThanksAlso fan stays on all the time,no fan switch on the dash????? Edited January 19, 2016 by Turker Quote Link to comment Share on other sites More sharing options...
wheeler73 Posted January 19, 2016 Share Posted January 19, 2016 Sounds like the idle was turned down by the cruise control switches inadvertently. The dealer can set the idle and then go into customer parameters and turn off the adjust low idle with crusie switches. I see this alot. 1 Quote Link to comment Share on other sites More sharing options...
Turker Posted January 19, 2016 Author Share Posted January 19, 2016 Sounds like the idle was turned down by the cruise control switches inadvertently. The dealer can set the idle and then go into customer parameters and turn off the adjust low idle with crusie switches. I see this alot.forget the point out that, Fan stays on all the time and there is no switch on the dash to over ride???? Quote Link to comment Share on other sites More sharing options...
wheeler73 Posted January 19, 2016 Share Posted January 19, 2016 Did they do any programming or software updates? Quote Link to comment Share on other sites More sharing options...
Turker Posted January 20, 2016 Author Share Posted January 20, 2016 Did they do any programming or software updates?No just oil ,filter change, grease Quote Link to comment Share on other sites More sharing options...
wheeler73 Posted January 21, 2016 Share Posted January 21, 2016 That is a new one. Could be a coincidence though. Which fan does it have air or electronic viscous? Quote Link to comment Share on other sites More sharing options...
Turker Posted January 21, 2016 Author Share Posted January 21, 2016 That is a new one. Could be a coincidence though. Which fan does it have air or electronic viscous?Air,checked solenoid it works fan hub moves in and out but it will not disengage. I will check the AC switch today??? Quote Link to comment Share on other sites More sharing options...
Dirtymilkman Posted January 21, 2016 Share Posted January 21, 2016 The mechanic may have accidentally unhooked or broke a wire or connector while doing the service. I'd check the wiring for the clutch. Quote Link to comment Share on other sites More sharing options...
Turker Posted January 25, 2016 Author Share Posted January 25, 2016 Today I went to Mack dealer,They hooked up to computer,no codes still running rough,change the solenoid for fan, did not stop the fan after $ 396.00 they told me it may have some air in the fuel system ,drive it few days and see what it does? Also they told me that my fan, designed to run all the time no free spool!!! why they did not tell me that before changing my solenoid?Does anybody have 375AI engine in granite to see if the fan stays all the time? Thanks Quote Link to comment Share on other sites More sharing options...
wheeler73 Posted January 26, 2016 Share Posted January 26, 2016 If it has the 2 speed air fan it does stay on but not at full speed until signaled to engage. This design saves the fan clutch from burning out quickly. Did the dealer turn up the idle speed? Quote Link to comment Share on other sites More sharing options...
mackey58 Posted January 26, 2016 Share Posted January 26, 2016 My boss has an ai 427 had the same problem with the fan not shutting off dealer changed fan selinoid no go the complete wiring harness and ecu on drivers side said the anti freeze was shorting it out no good all new a/c system all but that valve on the fire wall above a/c no good fan still on changed the valve above a/c box problem solved weeks of changing parts Quote Link to comment Share on other sites More sharing options...
Turker Posted January 27, 2016 Author Share Posted January 27, 2016 If it has the 2 speed air fan it does stay on but not at full speed until signaled to engage. This design saves the fan clutch from burning out quickly. Did the dealer turn up the idle speed?Dealer did not turned up the idle since there was no code, I am thinking that they should able to tell me the fan is normal for the model, after all they had all the info and vin # etc . Instead they change the solenoid with new one .my old one was working just the way new one did ????? It is all about taking advantage from the owner of the truck. Quote Link to comment Share on other sites More sharing options...
wheeler73 Posted January 27, 2016 Share Posted January 27, 2016 The idle can be turned up when they monitor the parameters. Sounds like they do not know what they are doing. Unfortunately there are not many of us left that know anything about VMACI-VMACIII. Sounds like you need to find a better dealership. It is a shame that there are less and less technicians that can program and do anything with the older electronics. Right now I am training a younger tech how to flash, reprogram, and how to set parameters on VMACIII. 1 Quote Link to comment Share on other sites More sharing options...
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