niceguypmp3 Posted August 12, 2018 Share Posted August 12, 2018 We just purchased a 2003 Mack with a 350hp E7 and a 5 speed allison auto with almost 500k miles and over 22k hours on the truck. We know nothing about the history on the engine and tranny. What should we look at first or possibly replace? The trans fluid looks nice and clean and clear, it definately needs the motor oil/filter changed as it's nice and black. I already scared myself and was kinda reading through some posts about the E7 and EGR issues. How do I know if this engine has an EGR or not? Quote Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/ Share on other sites More sharing options...
niceguypmp3 Posted August 12, 2018 Author Share Posted August 12, 2018 I also noticed driving it home after purchasing it that when pulling hills, then sometimes when you put the pedal down to pull the hill then the turbo spools up but then sometimes after 5 seconds or so then it will spool up even more and it has quite a bit more pulling power even though the tach doesn't move (it's not downshifting). It does it with the cruise on and also with it off so i don't see how it could be the pedal sensor. Could this be what they call a dual HP engine? Why would it be doing this? It didn't do it on every hill, sometimes it had the extra power immediately but other times it was delayed. Quote Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/#findComment-404023 Share on other sites More sharing options...
fjh Posted August 13, 2018 Share Posted August 13, 2018 Should be a non egr engine! 2004 was the anniversary Of EGR Celebrated daily/ weekly / monthly/ yearly at a shop near you! 😣 I would have your fuel pressure checked Also if it has a waste gated turbo it may be sticking ! 2 Quote Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/#findComment-404050 Share on other sites More sharing options...
niceguypmp3 Posted August 21, 2018 Author Share Posted August 21, 2018 I am also curious as to what the Torque rating would be on this 350hp E7? Quote Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/#findComment-404537 Share on other sites More sharing options...
niceguypmp3 Posted September 29, 2018 Author Share Posted September 29, 2018 no one knows the torque rating on this engine at 350hp? Also, any other ideas as to why sometimes when pulling then the truck is only running at like 1/2 throttle and then all of a sudden sometimes after 3 seconds other times after 30 seconds or so, then it will all of a sudden start pulling like it should at full throttle? it does the same thing on and off of cruise control. Also, I dont know if it's normal or not with an E7 but when taking off from a complete stop then there's a few second lag where it doesn't seem to want to hardly pull or spool the turbo. Is this some sort of emission or smog setting to prevent smoke at first pull off? It really sucks when loaded down and starting off cuz it doesn't want to immediately get out of the way and clear the intersection and then after the rpm's get up then it pulls good and hard. Quote Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/#findComment-406866 Share on other sites More sharing options...
41chevy Posted September 29, 2018 Share Posted September 29, 2018 (edited) On 8/20/2018 at 8:22 PM, niceguypmp3 said: I am also curious as to what the Torque rating would be on this 350hp E7? 1360 lbs. of torque @ 1200 /1250 rpm. Edited September 29, 2018 by 41chevy Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/#findComment-406873 Share on other sites More sharing options...
OldRedMack Posted October 10, 2018 Share Posted October 10, 2018 Pressure check your intake for leaks, and put a boost gauge on it. A boost gauge is fairly inexpensive and easy enough to install, and will help you diagnose issues. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/#findComment-407604 Share on other sites More sharing options...
Bigjohn4300 Posted January 31, 2019 Share Posted January 31, 2019 Hey we both have the same issue, sometimes my 04/300/Allison does the exact same thing! Sometimes from a dead stop, almost instant boost, good power...sometimes normal power, then sometimes won’t build good boost through first/second maybe into third before you hear the motor pitch deepen(more fuel)followed by rise in boost and normal power. Quote Link to comment https://www.bigmacktrucks.com/topic/54037-2003-mack-e7-and-allison-auto/#findComment-414554 Share on other sites More sharing options...
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