Jump to content
niceguypmp3

2003 mack E7 and allison auto

Recommended Posts

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?

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites
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 by 41chevy

Share this post


Link to post
Share on other sites

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.  

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Welcome to BMT!

...The world's best antique, classic & modern Mack Truck support forum! Founded in 2000, BigMackTrucks.com is the place to go for everything related to Mack Trucks!

BMT!

BigMackTrucks.com is owned and operated by Watt's Truck Center, New Alexandria, PA. This forum and it's contents are not affiliated with Mack Trucks, Inc. or Volvo Trucks North America.

×