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Trying to figure out an EUP without software


zeault
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Hey there folks,

I got a used mack CX with an etech.  The motor is a factory reman built to the original's 2001 spec.  Has about 625k miles.  Seems mechanically sound.

I can hear just a little bit of a misfire during idle.  Can't hear it while revved up.  Other people say they don't notice it but I know its there, and the ECU agrees with me.  I don't have the software but the lightning bolt blinks 8-3 for EUP.

Doesn't happen all the time.  Mostly just when started up cold.  I have had the lightning bolt come up on the highway though, and sometimes I think I hear it when I hop out and its idling hot.  Noticed that when it happens there's some white smoke out the blow-by tube, but when it stops the smoke goes away.  It does smoke out the blow-by tube when its good and hot regardless of the knock.  I assumed that was normal for 625k.

I probably have enough money to take it into a shop, but I'm a new owner/operator and I want to get more comfortable working on this motor myself.  Took the heat shield off and noticed the EUP #3 looks like it's been replaced before.  It looks wet in the picture because I used PB blaster on the harness screws.  I got the VMAC workshop manual 8-211 but its for the later ASET engines.  Can't find the 8-211 for my model year.  I did some of the continuity tests anyways and they checked out okay. 

I think I'd like to do an injector cutout test.  If I try disconnecting the wires from the EUP while the motor's running is that gonna hurt anything?  Then maybe I'll try swapping it with another EUP in a different cylinder and seeing if the problem follows?  I'll have to take those high-pressure lines off.  Do you have to bleed/prime those when you put them back on?  Never done it before.

Oh and it looks like I got a head gasket leaking onto #3.  Maybe that caused the EUP to go bad twice?  Or maybe the misfire cause the gasket to fail?

If you've got any wisdom or advice I'd really appreciate it.  Thanks

 

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the oil leak on the lower exhaust stud is not a head gasket. the lower studs are live into the pushrod, bore.. so if they are not sealed good or old, they will let oil seep out. swapping the EUP is good way to see if it follows, remove the return fitting from the block to drain the fuel out of the gallery then swap EUP's. take some emory cloth and touch up the ends of the fuel lines and blow some break clean thought the line to purge any debris out. when you install the lines, torque the lines to about 35-40 lbft, back them off a half a turn then torque to 25lbft.. just wing it... it's no biggie.. to bleed the lines,,, leave the nut at the head loose and prime the hand pump until fuel comes out of the lines, wait for the air bubbles to stop, then tighten that line, using the same torque procedure,( Torque conditioning) pump the primer again for each line that is loose. 2 will fire the engine, but 3 is better...  jojo

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I am not saying that the #3 hole doesnt have an issue, just talking about EUP swap, I see the oil leak is upward on the manifold, possibly an issue in the cylinder, because usually the stud is oily, however, I havent seen it all... jojo

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That is a lot of oil for a leaking stud, maybe clean it off and see how much it really leaks. It could have been leaking a while before you got it. If it leaks a lot again I’d suspect something on that cylinder. You could also have a slight leak on the bottom oring on that eup. 

Edited by Onyx610
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Thanks for all the advice.  And you all responded so fast too.

5 hours ago, fjh said:

... However! If the engine is not suffering from  performance issues or throwing up engine codes  other than an intermittent annoyance miss .I personally would not chase this! Only because I have done this before with no success ...

I forgot that the EUP's needed to be calibrated.  I know they'll probably work without calibration but I think it'll make it harder to chase down the issue if I swap them without doing it.  Maybe I'll wait until I can get the software to do it.  I might have found some software online for free (https://www.diesellaptops.com/products/v-maciii-software) but I'll have to put it on an old laptop to see if it's legit.  Gotta get a data link tool too.  Looking at this one because it's cheap: https://www.my-grandview.com/store/p1/Grandview_USB_Kit.html

In the mean time I'll clean up the oil and keep it running while watching the leaks.  Hopefully it doesn't get worse for a while.  Will a miss like this be damaging to the piston over time?

I'll post another update here if/when I get plugged into the ECU.  Then maybe I'll do the cutout test the right way.

Thanks again.  Great website.

-Jared

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Also keep in mind a lot of times diesel fuel and soot looks alot like oil. Also is the truck smoking at all? 

Edited by Onyx610
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cal codes are important, but the engine will run good without them.  however when all is repaired, the cal. codes should be installed...  'F' is right jojo

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3 hours ago, Onyx610 said:

Also keep in mind a lot of times diesel fuel and soot looks alot like oil. Also is the truck smoking at all? 

Nope clean exhaust while idling.  Can't really tell on the highway but I left a trailer looking a little sooty the other day.

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Okay time for an update!  Sorry it took so long but we had historic snowfall in Massachusetts so I had to shovel out the machine before I could work on it.  

First, the sludge running down the engine in my first picture appears to be seeping from the exhaust manifold gasket.  Not the head as far as I can tell.  And there's nothing but dirty air going through the manifold so it must just be oil working it's way through the stud?

Second, I hit the books a little and found this in the Etech service manual:

Quote

Make sure all EUP terminal wires are connected and tight. With
the engine operating at low idle (625–675 rpm), connect a jumper
wire across the EUP terminals one cylinder at a time. If the
cylinder is firing correctly, the engine sound will change. If a
cylinder does not change the engine sound, that cylinder is not
firing correctly.

This is a sort of cut-out test you can do without software.  I took a video of myself testing some of them and I almost dropped the camera because shorting #4 caused a small explosion.  It was okay afterwards.

As for the results of the test... well the sound 'changed' like they said it should but I was expecting most of the clacking to go away when I shorted one in particular.  It didn't.

It was warm today, never got the lightning bolt or had any blowby smoke.  I compared the engine noise in that video to one I took on a cold 8 degree F night when I thought I heard it and.... they sound the same.  I'll attach this video too its short.

Maybe there's nothing wrong with the motor and I'm just blowing this out of proportion because of a blinking lightning bolt and maybe Mack E7 motors just sound a lot clackier than I am used to.  I have never driven a mack E7 before I bought this truck, only the ones with the Volvo engine.  I got it for cheap but all the little noises it makes worry me because it is the first truck I've ever owned and I want to get the most out of it.

Check out both the videos. They don't sound quite the same as they do in person, but you'll get the gist.  Do I have a misfire or am I just losing my mind?

Video 1: https://1drv.ms/u/s!AsGeqBVYV5vqhdAeBI7_If4sbEpAVg?e=B28drv

Video 2: https://1drv.ms/v/s!AsGeqBVYV5vqhdAdAbMXaNn6720Biw?e=dhLeGJ

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  • 3 weeks later...

It might be a good time to go ahead and put a set of injectors in it.  In the grand scheme of things they are pretty inexpensive, about $100-$125 a piece depending on where you get them.  In my experiences if the manifold stud is leaking they usually come out pretty easy cause they are sitting in an oil bath.  Put a ratchet and socket on it and see if it turns.

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On 2/23/2022 at 7:39 PM, OldRedMack said:

It might be a good time to go ahead and put a set of injectors in it.  In the grand scheme of things they are pretty inexpensive, about $100-$125 a piece depending on where you get them.  In my experiences if the manifold stud is leaking they usually come out pretty easy cause they are sitting in an oil bath.  Put a ratchet and socket on it and see if it turns.

I have been thinking about the injectors.  I was really hoping the guy I took it to would offer me some more advice but he fixed the code and decided it was all set.  I read in the maint&lube manual that you're supposed to pull them all and clean/test them every 150K or so.  It is probably due for that.  Do you know where I can get nozzles for that price?  The mechanic I hired charged me $269 for a single nozzle from the local dealer, and even my aftermarket parts guy is higher than $125.

I'd reach for that remack nozzle six-pack but I already paid for that one new so now I only need five.  When I get back to town I'm probably going to buy a better torque wrench and go into the head myself.  Question for ya:  The book says always replace the head cover gasket with a new one.  Is that really necessary?  its just the cover.

The stud hasn't really leaked since I took it in.  It was probably just the jake gasket leaking onto it from above.

Thanks

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6 hours ago, zeault said:

I have been thinking about the injectors.  I was really hoping the guy I took it to would offer me some more advice but he fixed the code and decided it was all set.  I read in the maint&lube manual that you're supposed to pull them all and clean/test them every 150K or so.  It is probably due for that.  Do you know where I can get nozzles for that price?  The mechanic I hired charged me $269 for a single nozzle from the local dealer, and even my aftermarket parts guy is higher than $125.

I'd reach for that remack nozzle six-pack but I already paid for that one new so now I only need five.  When I get back to town I'm probably going to buy a better torque wrench and go into the head myself.  Question for ya:  The book says always replace the head cover gasket with a new one.  Is that really necessary?  its just the cover.

The stud hasn't really leaked since I took it in.  It was probably just the jake gasket leaking onto it from above.

Thanks

I use m&d distributors... bought six new ,and don't have to turn in your core.

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M&d was good to deal with, but call them with your injector numbers.  The website numbers don't always match up with what you need.  You can buy as many or as few as you want.  They are really only at there best efficiency for around 5k hours before you start losing some power and fuel efficiency.   I don't replace the valve cover gasket unless it's ripped or torn.  If it looks good just make sure it and the head surface is clean and smooth and you shouldn't have any problems with leaks. 

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