joes mack Posted February 27, 2010 Share Posted February 27, 2010 the trucking co that im working for has a prob with a 427 E tec in one of our RD 800 coal trucks the truck will run like mad as long as you keep the rpms above 1600 but if they drop below that the truck falls on its face loaded or empty the truck has been to the mack dealer many times the mechanic said hooked to computer and still no change it is timed right pumps have been changed. i told the owner that i would ask you all for help. i told him about this site and he said he would check it out he has 30 trucks 28 of which are macks and 2 ints (junk) no one wants to drive them and they are allmost new. i guess it is because they are too limber when you have 45 tons of coal an your back (off road). you just cant beat a mack with camel backs for standing up in soft muddy roads...joe Quote Link to comment https://www.bigmacktrucks.com/topic/12813-engine-problems/ Share on other sites More sharing options...
fjh Posted February 27, 2010 Share Posted February 27, 2010 the trucking co that im working for has a prob with a 427 E tec in one of our RD 800 coal trucks the truck will run like mad as long as you keep the rpms above 1600 but if they drop below that the truck falls on its face loaded or empty the truck has been to the mack dealer many times the mechanic said hooked to computer and still no change it is timed right pumps have been changed. i told the owner that i would ask you all for help. i told him about this site and he said he would check it out he has 30 trucks 28 of which are macks and 2 ints (junk) no one wants to drive them and they are allmost new. i guess it is because they are too limber when you have 45 tons of coal an your back (off road). you just cant beat a mack with camel backs for standing up in soft muddy roads...joeCan you give us some more info!What year is the truck ? What trans? What have they checked so far.Have they ever done a cam job on the truck?what kind of boost does it make, does it smoke if so what color is the smoke.Things to check fuel preasure , boost leaks !What does the pyro run at?Let us know! Quote Link to comment https://www.bigmacktrucks.com/topic/12813-engine-problems/#findComment-50304 Share on other sites More sharing options...
joes mack Posted February 27, 2010 Author Share Posted February 27, 2010 the truck is a 03 cam dont know smoke is black at about 1700 and up when pulling. and shifting gears. pyro/ boost dont know. but the truck i drive is a 99 or 2000 and the pyro runs about 11/1200 on the same haul. my truck has the same engine trans 8speed fullers 6.73 rears. my truck dont bog down when the rpms get below 1600 it pulls good down to 1300. if you need more info i will try to talk to the mechanic and driver tomorrow and ask if they know what boost/pyro runs and about the cam. joe Quote Link to comment https://www.bigmacktrucks.com/topic/12813-engine-problems/#findComment-50307 Share on other sites More sharing options...
fjh Posted February 27, 2010 Share Posted February 27, 2010 the truck is a 03 cam dont know smoke is black at about 1700 and up when pulling. and shifting gears. pyro/ boost dont know. but the truck i drive is a 99 or 2000 and the pyro runs about 11/1200 on the same haul. my truck has the same engine trans 8speed fullers 6.73 rears. my truck dont bog down when the rpms get below 1600 it pulls good down to 1300. if you need more info i will try to talk to the mechanic and driver tomorrow and ask if they know what boost/pyro runs and about the cam. joeJoe Ya should tell em to check for boost leaks check the air cleaner ect if the pyro gets that hot that fast its not likly getting enough air! Quote Link to comment https://www.bigmacktrucks.com/topic/12813-engine-problems/#findComment-50323 Share on other sites More sharing options...
joes mack Posted February 28, 2010 Author Share Posted February 28, 2010 talked to the mechanic he said the engine was rebuilt with new cam installed about a year ago. new after cooler. new turbo. new rubbers on the pipes. and new air filters 2 weeks ago and the truck still wont run right and he has no clue on what else to do to it. i told him that some of the members on here were mechanics at mack dealers and he said to ask for help .... (i told him about reprograming the computer ) what do you guys think ..joe Quote Link to comment https://www.bigmacktrucks.com/topic/12813-engine-problems/#findComment-50366 Share on other sites More sharing options...
fjh Posted February 28, 2010 Share Posted February 28, 2010 talked to the mechanic he said the engine was rebuilt with new cam installed about a year ago. new after cooler. new turbo. new rubbers on the pipes. and new air filters 2 weeks ago and the truck still wont run right and he has no clue on what else to do to it. i told him that some of the members on here were mechanics at mack dealers and he said to ask for help .... (i told him about reprograming the computer ) what do you guys think ..joeJoe When did the power problem show up?If it showed up around the time of the rebuild I would be suspecting the wrong cam key was installed ,there are three cam key selections.Not sure which key was to be used for the 427 but this could be the problem.How ever there are other places the intake can leak the air compressor inlet and intake gaskets is another possible place the hose on the air compressor inlet is a comon leak on some models of truck CV model this was quite common if the comp is plumbed to the inlet manifold check this out. Quote Link to comment https://www.bigmacktrucks.com/topic/12813-engine-problems/#findComment-50379 Share on other sites More sharing options...
joes mack Posted March 3, 2010 Author Share Posted March 3, 2010 things people will do when they get mad at the trucking co when something dont go their way the mec took the manifold off of the truck to check replace the gaskets and found two bolts wraped with alu duct tape in the manifold. too big to get into the ports of the head but still big enough to cause problems put it back together and the truck runs better than mine now that it can get the air that it needs to let the bulldogs run and not fall over gasping for air. joe Quote Link to comment https://www.bigmacktrucks.com/topic/12813-engine-problems/#findComment-50532 Share on other sites More sharing options...
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