Mack E7 question

[Serv]

I just bought a 2003 Mack CX 613 with a 427 horse E7 with 507k miles. Is there any way to read fault codes without the scanner? I ask this because someone told me you can manipulate certain speed and other settings in the computer by pressing a certain combination of buttons on the dash and somehow entering the last so many numbers of the VIN. Could this be true?

We put a computer on it at the dealership that sold it to me (6 hours away from me now) and it showed a code that said "engine position sensor-erratic idle" We swapped in a new sensor and the problem went away for about the first 3 hours of driving then it came back. What's happening is when hot, it idles smoothly for about 3 seconds then I get a split second "upward" surge where it jumps up about a hundred RPM. About evdry three seconds or so I get that slight upward jump in the RPM. Also, my driver reported an occasional check engine light on his 380 mile loaded trip yesterday but I have yet to see a CEL when I've drove it about 6 hours with no trailer.

I've tried googling for a self test function in these engines but I can't find anything.

[Jeff D.]

Serv, my Mack, also a 2003 CX613 (but with a 460 instead) has had a jumpy idle when hot since new. Dealership could not get it to not do it either, but told me some Macks just have this problem.

I've over 500k miles on it now and it still has a jumpy idle, and acts just like you described. I've also intermittant CEL that'll come and go, dealership has no clue why, thought grounds?? Mine will even shut down for a split second while going down the road, and then start right back up. Freaks me out when it happens while going through an intersection. Guages will bottom out and come back too, sometimes. Mine has done all this since new, hasn't gotton any worse, and I'm to the point now I just figure it's a Mack (and that's not in a good way)

I could go on and on about my dealings with Mack over this stuff and more, but won't.

You can check your codes with the cruise control switch's, but you must have a stored code (ie, CEL stays on) You do itby having key on, cruise power switch off, and hold RESUME/ACCEL switch on until CEL light goes out. The light will start flashing the codes. It'll be a two digit #, with a slight pause between seperate codes.

I have the list of codes, and can copy them for you, but it'll have to be tonight, gotta go make some money right now.

Good luck!!

[Serv]

Thanks Jeff.

I will surely take you up on the list of fault codes. I can't find that list anywhere on the web.

I don't have a constant CEL but like I said, my driver told me yesterday that he saw the lightning bolt symbol light up on the dash a few times while on the road. Also, the guy that read my codes with the hand held did so while the truck was doing the rough idle and warm. We did not have a constant CEL at the time.

One thing worth mentioning is the mechanic at the dealership said he saw some metal on the sensor we replaced. The sensor is located on the passenger side front by the timing gear area. I didn't see the metal he spoke of but I went ahead and pulled it out last night to see if there was any more metal on it. I didn't really see any fragments worth worrying about. A friend of mine that used to work at a local Mack dealer said that if there was to have been metal particles on the sensor after such a few amount of miles that the gear set may be going bad and would need replacing. That sensor is highly magnetized though. I wiped the sensor clean and put it back in and the jumpy idle went away again.

Did the Mack dealer happen to show you where these possible bad grounds were located? I don't mind cleaning them up if so.

another thing that kinda bothers me is the blowby coming from this engine. Everyone I've talked to says it's relatively normal for a Mack (since it's not puffing it out, just a steady stream when hot only) so I'm not really gonna worry about that.

also, I have a pretty bad oil leak coming from behind the lower twin filters on the drivers side. and a not so bad oil leak coming from where the turbo drain tube meets the oil fill tube. Looks like someone tried to shove some silicone in there to fix it but it didn't work so well. Other than that, it's a very nice, clean truck. It used to be a Warrior Express sleeper truck that was chopped into a day cab. Due to the colors it's sporting, (gold/burgundy) we call it the peanut butter and jelly truck.

here's the one I bought. I really love the way it drives.

http://houston.freewaytrucks.com/fmi...find~-find.htm


Sounds like you know your Mack's pretty well.

[Serv]

Mine will even shut down for a split second while going down the road, and then start right back up. Freaks me out when it happens while going through an intersection. Guages will bottom out and come back too, sometimes.

You would think it would be in their best interest to identify and take care of that one before anything else!

[Jeff D.]

I will surely take you up on the list of fault codes. I can't find that list anywhere on the web.

Here ya go! Sorry for the poor quality, but the important stuff is all legible. The most common code I have is the "92". That's the code that pops up when the truck stalls/refires. It also is the final code in the list. There's none past 92 (it looks like some may be cut off in the pic scan, but not)

When I said it start back up on it own, I should've said if the tranny's in gear and the motor's still spinning because it has too (coasting down), it'll fire right back up. If I had the clutch pushed in when it stalled it'd die completely and I'd have to spin it over again via the key.

My problems, and yours too, are not uncommon with these model/year Macks. They should have TSB's (or whatever Mack may call them)on all those problems, including the ground repairs, although the ground fix did nothing to change any of my problems.

They are irritating, but they haven't left me stranded nor gotton worse since I bought the truck new, so I live with them. You're right though, Mack should've fix them, and under warrenty.

Good luck, and if you do find a fix for the idle issue, let me know so I can get it done too.
Thanks!

[Jeff D.]

I forgot,, I didn't answer these:

Did the Mack dealer happen to show you where these possible bad grounds were located? I don't mind cleaning them up if so.

They mentioned like 7 different places they had to go and clean the grounds, plus they added a new one from the main harrness behind the instrument cluster, goes through the firewall, and attaches by a large wire connector below overflow tank area. That's about all I remember, but maybe/hopefully Mack can give you a TSB on that.

another thing that kinda bothers me is the blowby coming from this engine. Everyone I've talked to says it's relatively normal for a Mack (since it's not puffing it out, just a steady stream when hot only) so I'm not really gonna worry about that.

Mine has some blowby, but less than the Detroit's Series 60's I've had, but alittle more than the Cat 3406's. Mine is also most noticeable when it's hot, but cooling down, like if I just pulled into a pickle park after running hard.

also, I have a pretty bad oil leak coming from behind the lower twin filters on the drivers side. and a not so bad oil leak coming from where the turbo drain tube meets the oil fill tube.

Mine had that same leak behind the filter mount housing, and I had it fixed. Mine wasn't a super bad leak, but since the oil/coolant heat exchanger is there I figured I didn't want any chance of those fluids getting transferred/mixed (ie, antifreeze in the oil ) so I had it fixed.

Mechanic said it wasn't a bad job, but it did require draining the anti freeze.

[Serv]

Thank you very much Jeff. Although we don't have a steady check engine light at the moment, I'm sure we will before long. I will update the thread as this progresses.

[catken]

We were all Mack until last week. Bought a new Pete service truck and will start replacing all the Mack semi tractors. Just to many problems.

[Serv]

We were all Mack until last week. Bought a new Pete service truck and will start replacing all the Mack semi tractors. Just to many problems.

What kind of Macks do you run and what problems are/were you guys having?

[Serv]

Well I pulled a late nighter working on this truck last night and addressed quite a few gremlins. I fixed a turbo drain leak which was just an o-ring and gasket and also removed, cleaned and went through the entire oil cooler/filter base setup. Drained all the antifreeze, a couple o-rings for the oil cooler setup, gasket to the block, oil change while I was at it then replaced the antifreeze and some new 15-40 weight oil. I replaced the Baldwin oil and fuel filters with genuine Mack filters and have zero leaks so far today. Oil temp is down now and I can honestly say this truck is starting to grow on me.

I still get a slight intermittent idle, but it seems to be doing it a lot less then the other day. One thing that I thought I'd mention is that the engine position sensor around the geartrain at the front of the motor (the one that the handheld reported to be causing the idle isssue) has a twin sensor mounting down at the bottom rear driver's side of the engine. I pulled that one last night and wiped some small metal fragments and it seemed to improve the idle.

Just a thought if you haven't pulled to check those sensors Jeff. They are highly magnetic sensors and will pick up small metal that the come in contact with. Also, when I pulled the oil drain plug (the oil was pretty black) I pulled it straight out and inspected it. Zero metal on the magnetic plug. Not even metal dust buildup on it so I guess that's a good thing.

[Serv]

Another thought Jeff. The local Mack guru gave me a quick look over a truck at the local dealership yesterday. There's a junction box located right next to what looks like a starter relay on the firewall. He said that when that thing goes out or cracks internally, you will experience all kinds of wacky things. Might be worth checking that. He said that since he diagnosed his first one, he made a habit of grabbing the wire/terminal and wiggling looking for play from the outside of this box. Says that's a sure sign of a bad one and it will wreak havoc on the electrical system will random phantom electrical issues. If you need a pic of this box on my truck, just let me know and I'll take some for you.

[Jeff D.]

Serv, I've not messed with the sensors at all yet. My truck has idled like it does from day one. At just over 200k miles I lost 3 lobes off the cam from cam followers seizing. They pulled the engine down (front geartrain included), and replaced everything bad. I hope they would've cleaned the metal from the sensors at that time but Might be something for me to check.

The local Mack guru gave me a quick look over a truck at the local dealership yesterday. There's a junction box located right next to what looks like a starter relay on the firewall. He said that when that thing goes out or cracks internally, you will experience all kinds of wacky things. Might be worth checking that. He said that since he diagnosed his first one, he made a habit of grabbing the wire/terminal and wiggling looking for play from the outside of this box. Says that's a sure sign of a bad one and it will wreak havoc on the electrical system will random phantom electrical issues. If you need a pic of this box on my truck, just let me know and I'll take some for you.

That'de be great!! I wish I had an expert to work on mine. I've not stepped foot in my local Mack shop in better than two years since all my troubles. I have to travel 180miles south to another Mack dealership now for any work my regular independant shop can't do. They (my indep.) are not "Up" on all things Mack, but do their best for me.

I went and took some pics of the ground the dealership added on mine to see if it is connected to the same part. It connected inside to the back of the instument cluster, came through firewall (first pic black wire right of box), and goes up along the inside of the overflow tanks to the connection I'm pointing at.

I also took a pic of another common Mack fix. The AC switch. The little push button one burns out. I replaced mine with a toggle switch. It's hard to wire in being it's against a board, but better than continuously replacing the stock switch.

[catken]

We have had turbo prlblems, oil leaks, electrical, and whatever else. The one tractor is always down it seems and the warrenty takes care of it. Two other new one is having computor problems. We have 3rd axles on all of them and pull side dumps and belly dumps with them, also lowboys. Next tractor will be different with 550 or 600 Cat. Our old 2000 Macks have really done well but these new ones are a head ache Serv. Ken

[Tn Bulldog]

come join us over @ http://WWW.BIGMACKTRUCKS.COM



They are some knowable folks there & we will be glad to have yall




bulldog

[King of Obsolete]

buddy barry has the blue mack which is a E7and the thing is acting up. driving it at highway speed, all it does is act as if sme one is turning the key on and off. the electronic malfuction light comes on and goes off. we have to drive the truck 1200 kms to the nearest mack dealer which treats us pretty good. they can't guess what the problem is on the truck over the phone.

thansk
KoO
Published Author