jsh40 Posted September 10, 2010 Share Posted September 10, 2010 Hello all, I am new to this site & in desperate need of some tech. info for a 2004 ai 400 engine. this unit has a chirping sound that comes & goes & #5 injector line is leaking through the fitting in the head.We replaced the line but now leak has returnned so we replaced line again & still leaks. Next step is replace injector #5 but only makes sense to do all injectors to eliminate any chance of cyl. imbalance issues.Unit is RD tri-axle dump with 300+miles on it. From reading this forum I found out that these AI engines were prone to shearing locating pin off of lifter & letting lifter turn in bore causing cam failure. Also I see there is a servcie bullitain for mounting hardware in valve train. I am a licenced mechanic & also I am ASE certified master truck technician but the problem is I have not worked on Mack since 2001. If anyone can & wishes to shed some light , has an opinion or can help me with some tune up specs.(timming mark location,valve lash settings,JAKEBRAKE lash,torque specs for rack,housing & cover). I am fixing this truck for a friend of mine & it is currently losing $100 an hour sitting & waitning for parts. With any luck I will be able to get it back together Saturday. I will gladly offer my experience & or opinion to any & all who can help out here. Quote Link to comment Share on other sites More sharing options...
rhasler Posted September 10, 2010 Share Posted September 10, 2010 Hello all, I am new to this site & in desperate need of some tech. info for a 2004 ai 400 engine. this unit has a chirping sound that comes & goes & #5 injector line is leaking through the fitting in the head.We replaced the line but now leak has returnned so we replaced line again & still leaks. Next step is replace injector #5 but only makes sense to do all injectors to eliminate any chance of cyl. imbalance issues.Unit is RD tri-axle dump with 300+miles on it. From reading this forum I found out that these AI engines were prone to shearing locating pin off of lifter & letting lifter turn in bore causing cam failure. Also I see there is a servcie bullitain for mounting hardware in valve train. I am a licenced mechanic & also I am ASE certified master truck technician but the problem is I have not worked on Mack since 2001. If anyone can & wishes to shed some light , has an opinion or can help me with some tune up specs.(timming mark location,valve lash settings,JAKEBRAKE lash,torque specs for rack,housing & cover). I am fixing this truck for a friend of mine & it is currently losing $100 an hour sitting & waitning for parts. With any luck I will be able to get it back together Saturday. I will gladly offer my experience & or opinion to any & all who can help out here.You may have bad o-rings on the injector body that are allowing oil to enter the sleeve on the line and consequently leak at the fuel line nut on the cylinder head. No timing is necessary to install the injectors, just make sure the pin in the injector body lines up with the slot in the sleeve in the head. Intake lash is .016" exhaust is .024". The engine probably has a Powerleash and not a Jake. Settings and adjustment procedures for the Powerleash are different than on a Jake. If you have a Powerleash and you remove the rocker assemblies REPLACE THE BOLTS. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
jsh40 Posted September 10, 2010 Author Share Posted September 10, 2010 This engine has JAKEBRAKE housing with JACOBS tags on the housing. This is fuel leaking out of nut not engine oil. Do I not have to remove the Jake housings or rocker shafts to get at these injectors? Quote Link to comment Share on other sites More sharing options...
rhasler Posted September 10, 2010 Share Posted September 10, 2010 This engine has JAKEBRAKE housing with JACOBS tags on the housing. This is fuel leaking out of nut not engine oil. Do I not have to remove the Jake housings or rocker shafts to get at these injectors?You will have to remove the Jake Brake assemblies and the spacers to remove the injectors. The setting for the Jake should be .021". Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
fjh Posted September 11, 2010 Share Posted September 11, 2010 You will have to remove the Jake Brake assemblies and the spacers to remove the injectors. The setting for the Jake should be .021".Bro you need to address the churp sound before going after the valve set pull the pan and check the cam!That churp is likly a lifter or cam failing they don't always fail on an injection lobe!Injector orings can leak yes that is likly your leak! Quote Link to comment Share on other sites More sharing options...
jsh40 Posted September 11, 2010 Author Share Posted September 11, 2010 (edited) what is the fix for the chirp. I do believe the cause is one of the lifters rotating in its bore due to sheared locating pin. What is the torque on the injector hold downs,jake hsng & box. Unit also has intermittent loss of power & blueish white smoke pours out. I suspect bad o-rings on injector can cause this, yes? Edited September 11, 2010 by canman Quote Link to comment Share on other sites More sharing options...
fjh Posted September 12, 2010 Share Posted September 12, 2010 what is the fix for the chirp. I do believe the cause is one of the lifters rotating in its bore due to sheared locating pin. What is the torque on the injector hold downs,jake hsng & box. Unit also has intermittent loss of power & blueish white smoke pours out. I suspect bad o-rings on injector can cause this, yes?Bro your wasting time doing a valve set Yes Do the injector orings then pull the pan and look at the cam these Engines are time tested unlike the volvo mp engine they do certain things make certain noises this is a classic lifter chirp by what you discribe!50 pounds injectors 20 pounds or so on the lids 45 to 55 0n the jakes But don't bother putting any of it on till you check the cam!I only takes a half hour to pull the pan down worth the time as far as Im concerned! Quote Link to comment Share on other sites More sharing options...
jsh40 Posted September 12, 2010 Author Share Posted September 12, 2010 UPDATE: Turns out my chirping sound was #6 injector fire ring blown out(found three little pieces left of it). I replaced all the injectors & engine now purrs & the chirping is now gone. Under load this cylinder was losing compression into the injector cup (made for a real fun time getting #6 out of its hole,took me 2hrs on #6 & the rest I had changed in an hour & half. I am a Peterbilt/KW Tech. currently but I have much experience with all other makes & I very much appreciate the help you guys gave me. If there is anything I can help anyone with please don't hesitate to ask me.I specilize in diagnostics & troubleshooting & am not always right but I offer my opinion to any & all who have questions.Once again thanks for the help & hope I can return the favor.Sincerely,Jim Quote Link to comment Share on other sites More sharing options...
fjh Posted September 12, 2010 Share Posted September 12, 2010 UPDATE: Turns out my chirping sound was #6 injector fire ring blown out(found three little pieces left of it). I replaced all the injectors & engine now purrs & the chirping is now gone. Under load this cylinder was losing compression into the injector cup (made for a real fun time getting #6 out of its hole,took me 2hrs on #6 & the rest I had changed in an hour & half. I am a Peterbilt/KW Tech. currently but I have much experience with all other makes & I very much appreciate the help you guys gave me. If there is anything I can help anyone with please don't hesitate to ask me.I specilize in diagnostics & troubleshooting & am not always right but I offer my opinion to any & all who have questions.Once again thanks for the help & hope I can return the favor.Sincerely,JimWow! Good news! that would have thrown anybody off track, good thing you stuck to your guns and pulled the injectors ! good find Thanx for posting your fix!Lot Better than doin a Cam job! Quote Link to comment Share on other sites More sharing options...
rhasler Posted September 12, 2010 Share Posted September 12, 2010 I've seen a few trucks in the last year or so that had leaking injector sleeves in ASET heads, allowing fuel in the coolant and vice versa. This is something I had never seen happen since the introduction of the 4 valve heads on the E-6 engines. It doesn't seem to have been a predominant failure, as it has been with some other engines. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
jsh40 Posted September 13, 2010 Author Share Posted September 13, 2010 I suspect the cause of this problem was neglect on the part of the last tech to work on top end of this engine. I found the injector caps on cyl#5 & #6 not torqued to 45-50ftlbs. #6 had maybe 15-20ftlbs & I suspect that this it what caused the nozzle seal to be blown out. It cooked the orings on #5 also as it was not torqued correctly either. I am very happy not to have to do cam job as $$$$ are tight but I remain causously optomistic about the condition of the cyl. head & particularily #5 #6 injector cups. Still have problem of coolant res. leaking out of overflow cap but engine runs & pulls great with lots o power & no smoke. I have not pulled the y coolant hose off & checked the screen on oil cooler but I suspect this may be problem. Quote Link to comment Share on other sites More sharing options...
fjh Posted September 13, 2010 Share Posted September 13, 2010 I suspect the cause of this problem was neglect on the part of the last tech to work on top end of this engine. I found the injector caps on cyl#5 & #6 not torqued to 45-50ftlbs. #6 had maybe 15-20ftlbs & I suspect that this it what caused the nozzle seal to be blown out. It cooked the orings on #5 also as it was not torqued correctly either. I am very happy not to have to do cam job as $ are tight but I remain causously optomistic about the condition of the cyl. head & particularily #5 #6 injector cups. Still have problem of coolant res. leaking out of overflow cap but engine runs & pulls great with lots o power & no smoke. I have not pulled the y coolant hose off & checked the screen on oil cooler but I suspect this may be problem.You likly don't have to worry on the injector cup as it is the bottom of the head (cast) the injector is mounted in in a sheath pressed into the head.Yup ya did good I'll be puttin this one in my memory bank as I never would have thought a chirp would develop by an injector I have seen one stuck so bad the injector insert came up with the injector and had to use a porta power to pull it and of coase it was No 6 the hardest one to get to! Your Hired! even thou you are a PETE guy! We won't hold that against ya! Quote Link to comment Share on other sites More sharing options...
jsh40 Posted September 13, 2010 Author Share Posted September 13, 2010 (edited) lol. actually the old Macks were always my favorite. Edited September 13, 2010 by canman Quote Link to comment Share on other sites More sharing options...
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