jzack Posted July 28, 2022 Share Posted July 28, 2022 Well this was an awful experience. Been driving this truck for 28 years with no major issues. Over 1.3 million miles, 45,000 hours all original engine, even down to the turbo. I left with my second run for the day and the accelerator started acting funny. When I would let up to grab the next gear the RPMs would immediately drop too fast for me to grab the next gear, then they would come back. Like the accelerator lost signal momentarily. Did this twice, then the electronic malfunction light came on and the engine de-rated. Great I thought. So I started moving to the shoulder, pushed in the clutch to grab a lower gear and, BAM the engine immediately went WOT!!! Of course I panicked for a second, turned the key off, no response from the engine. I got it pulled over, remembered reading about runaway engines and what to do, so I grabbed my jacket and stuffed it in the air cleaner intake. That slowed it down to what sounded like a safe RPM but she kept going! White smoke pouring out the exhaust. Now what? Next, I grabbed a wrench and started to crack loose the fuel line to the filter tree. Two or three turns and it finally shut down. Whew!! Not sure how long it ran like that but probably a good 2-3 minutes at least. So disappointing, I'm sure anything in or attached to the engine will be suspect for failure now. An old mechanic at Mack suspects something gave way in the injection pump. We'll see I guess. They are a week out on service work. Three weeks to re-build the pump maybe. The worst part is, short of a full overhaul, not sure I can trust this engine again. Am I right? Before this, she was still running strong with no issues or symptoms whatsoever. On a side note, my Old Man, who I love but enjoys Monday morning quarterbacking, said I should have jammed it in gear and side stepped the clutch? Not sure the drivetrain would have enjoyed that experience though..... Quote Link to comment Share on other sites More sharing options...
67RModel Posted July 28, 2022 Share Posted July 28, 2022 Man where to start.....I guess it depends if you run local or over the road. If your mechanic opens up the pump and finds the problem in there just have the pump overhauled (this needs done regardless if you overhaul the engine or not) and then put it back on. Fire it up and see how it idles/responds on a few bobtail miles. If that checks out try a loaded run locally (if possible) and go from there. Its not a lot of work to pull the pump and reinstall it just to see. You might get lucky and get another 150,000 miles out of it. Plus if your local you can probably more easily absorb a breakdown / tow bill if it gives up on you. I'm sure there will be a bunch of others that come along and give some advice on some mechanical things to check for in order to determine if an overhaul is in the cards now. I'm just thinking in logistical and economics here..... 1 Quote Link to comment Share on other sites More sharing options...
jzack Posted July 28, 2022 Author Share Posted July 28, 2022 67RModel, thank you, yes I'm local so I could go in baby steps like you said and see how it responds. Thinking about at least pulling the valve covers and inspecting, send the oil out for analysis too maybe....I would think the shop would have a check list before starting a runaway engine either way. My mechanic mentioned rebuilding or replacing the Econovance too, but they are NLA and the pump shop said they don't work on them either. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted July 28, 2022 Share Posted July 28, 2022 re-building the inj. pump would be a good start. . yes check the top end for bent pushrods and hopefully no broken rocker arms.. when you drain the oil, I suggest having a kitchen strainer with you to drain the oil through.. just in case there are chunks in the pan.. if water is the first thing that comes out when you pull the drain plug, well, a rebuild will be in order.. also, are you sure it was a fuel issue, and not oil passing through the turbo? pull the CAC boots off and the turbo inlet boot, to look for oil.. There is a handful of checks you can do, before diving into a re-build.. Keep in touch.. Many smart guys here to help guide you as needed.. as far as pulling the injection pump... bring the engine up on the degree mark that is on the pump tag, (hopefully its still there). if not we can get the setting.. pull the air compressor, then pull the pump, and dont turn the engine around, unless you are confident on how to bring it back to the timing mark for the pump,,, its really not hard to do, just pay attention to detail.. Good luck, Jojo Quote Link to comment Share on other sites More sharing options...
jzack Posted July 28, 2022 Author Share Posted July 28, 2022 Joey Mack, thanks, I'll make sure to check the top end and pay attention to the oil. As far as the turbo, I didn't see oily residue in the stack. The accelerator issue (cutting out) and electronic malfunction light don't seem to point to the turbo. The idle had a slight lope to it right before this happened too..... Quote Link to comment Share on other sites More sharing options...
fjh Posted July 28, 2022 Share Posted July 28, 2022 Bummer ! Yup all of the above ! As the boys have said ! The push rod thing is the easiest tell tale ! Unfortunately the weak point here is the lifters! and valves! Even if you don't have any bent push tubes your lifters will always be in question after this event, Any kind of valve float on these can crack the lifter face IF its got old style lifters! The new style lifters a quite resistant to this however guess time will tell! 1 Quote Link to comment Share on other sites More sharing options...
Licensed to kill Posted July 28, 2022 Share Posted July 28, 2022 A couple thoughts from the peanut gallery. First, I would check the ECM and see what exactly was the RPM that it peeked at. That should tell you the likelihood of damage. Second, while runaways are often cause by a failed oil seal in the turbo, in this case, since cracking a fuel line shut it down, that would suggest to me that the runaway was running on fuel, not oil so that would eliminate the turbo as a cause. Being a "over fuel" condition, there is a good chance that the RPM did not get TOO high, not like a runaway due to oil feeding since the fuel lines can only provide so much fuel. 2 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted July 28, 2022 Share Posted July 28, 2022 good point about cracking fuel lines to shut it down.. jojo Quote Link to comment Share on other sites More sharing options...
jzack Posted July 28, 2022 Author Share Posted July 28, 2022 fjh and LtK, very good info, I'll definitely take into account. Thank you! Quote Link to comment Share on other sites More sharing options...
fjh Posted July 28, 2022 Share Posted July 28, 2022 (edited) 7 hours ago, Licensed to kill said: A couple thoughts from the peanut gallery. First, I would check the ECM and see what exactly was the RPM that it peeked at. That should tell you the likelihood of damage. Second, while runaways are often cause by a failed oil seal in the turbo, in this case, since cracking a fuel line shut it down, that would suggest to me that the runaway was running on fuel, not oil so that would eliminate the turbo as a cause. Being a "over fuel" condition, there is a good chance that the RPM did not get TOO high, not like a runaway due to oil feeding since the fuel lines can only provide so much fuel. depending how old the program the rpm log May not be view able! Also years ago as a comparison as LTK Mentioned We had a customer whos engine blew a turbo He was unable to get it toned down it screamed for 20 minutes blew the top off the rad and it rattled it self to a stop after 20 min !He tried to stall it but he was between gears couldn't get it back in when it happened just like you! He Did not get lucky! So Hope fully you may have gotten lucky! Edited July 28, 2022 by fjh Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted July 28, 2022 Share Posted July 28, 2022 Help me on this "F" can you download the last event from V-Mac II ?? I have never done it before,, V-Mac III, yes.. anyway.. I would just like to know, but all-in-all.. Physical inspection, is the way to go.. He is lucky, really... I still wish I had bought a Pro-link 9000 with V-Mac cartridges.. I would buy one today if I could find one.. jojo Quote Link to comment Share on other sites More sharing options...
Mark T Posted July 28, 2022 Share Posted July 28, 2022 Yikes. Lucky if it doesn't drop a valve shortly after. FYI, a hammer busts that fitting off a lot quicker than a wrench. Still if nothing happens right then and there, still likely valve train issues (that can be catastrophic) follow shortly. Maybe it's a good time to think about a major overhaul and new pump. Sounds like it's earned that, and I'm guessing you like the truck as it is (or was until this event) 1 Quote Link to comment Share on other sites More sharing options...
JoeH Posted July 28, 2022 Share Posted July 28, 2022 Check the oil level before you drain it, if it was running on oil then the level would likely be low? Quote Link to comment Share on other sites More sharing options...
fjh Posted July 28, 2022 Share Posted July 28, 2022 (edited) 26 minutes ago, Joey Mack said: Help me on this "F" can you download the last event from V-Mac II ?? I have never done it before,, V-Mac III, yes.. anyway.. I would just like to know, but all-in-all.. Physical inspection, is the way to go.. He is lucky, really... I still wish I had bought a Pro-link 9000 with V-Mac cartridges.. I would buy one today if I could find one.. jojo Kinda doubt full that you can access that info at all on VMAC 2 ! POSIBLY with the VMAC Software IF you happen to have it on an computer some where! Don't forget everything started out in DOS operating system Before windows Came Along! and you had to use the Prolink 9000 as an interface! WAY OVER My head! Edited July 28, 2022 by fjh Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted July 28, 2022 Share Posted July 28, 2022 yeah, there wont be a ,, so-called,,, download... this one is about being a Mechanic.. plain and simple,,, Like I was taught many years ago,,,, "The Metal Don't Lie"... I bet this will be a re-build of a good engine block, provided the crank is in good shape.. I always drop the 13 cap's, one at a time to inspect the crank before I go deep... A bad crank, makes a huge difference, on how to go forward.. Jojo 1 Quote Link to comment Share on other sites More sharing options...
jzack Posted July 28, 2022 Author Share Posted July 28, 2022 fjh, thanks, maybe I should consider myself lucky here. The tow truck driver said that many times a runaway engine ends with the truck burning to the ground!! Also, as luck would have it the boss (my sister) is leasing me a brand new 2023 Kenworth to break in while my truck is in the shop. Should be interesting, I haven't driven a new truck since I started driving my Mack in 1995. At that time, it was the best truck I had ever driven. Probably why I kept it so long. Quote Link to comment Share on other sites More sharing options...
Hayseed Posted July 28, 2022 Share Posted July 28, 2022 11 hours ago, jzack said: Been driving this truck for 28 years with no major issues. Over 1.3 million miles, 45,000 hours all original engine, even down to the turbo. I agree with mark T.. 38 minutes ago, Mark T said: Maybe it's a good time to think about a major overhaul and new pump. Sounds like it's earned that I reckon It's well & truly earnt a Rebuild.. 1 Quote "Be who you are and say what you feel...Because those that matter...don't mind...And those that mind....don't matter." - Link to comment Share on other sites More sharing options...
Joey Mack Posted July 29, 2022 Share Posted July 29, 2022 I wish we were closer to each other... I would love to build your E-7.. and save you around $15,000.00 .. I just did 2 in the last 5 weeks.. an ASET-C and an E-Tech.. parts and labor for both was under $35,000.00... with re-man heads and cam sets,, same customer.. Yes PAI engine kits... one turbo was newer, re-used it... the other got re-built.. both trucks are haulin dirt.. anyway, to turn this around wont cost $40,000.00 like Mack would tell you, if they even have a guy that knows how to build it.. good luck with the KW.. keep in touch, jojo Quote Link to comment Share on other sites More sharing options...
jzack Posted July 29, 2022 Author Share Posted July 29, 2022 Joey Mack, thank you, I appreciate the sentiment. I was literally across the street from our local Mack dealer when this happened, so I thought it was fate to have it towed there. They do have a few old timers left there that really know their stuff and I'm friendly with the service manager there. I wouldn't hesitate to have them do a full re-build but the $$$ would be crazy. Hopefully a pump is all it needs to get it running, then I can bring it to our shop for a full re-build some time in the near future. I'll keep you all posted. 1 Quote Link to comment Share on other sites More sharing options...
Licensed to kill Posted July 29, 2022 Share Posted July 29, 2022 14 hours ago, jzack said: On a side note, my Old Man, who I love but enjoys Monday morning quarterbacking, said I should have jammed it in gear and side stepped the clutch? Not sure the drivetrain would have enjoyed that experience though..... Easier said than done. Unless you catch it, understand what is going on and react in the first couple hundred RPM, aint no way you are going to stab that thing in gear. "jam it in gear and side step the clutch" is like telling a cop to shoot the guy that surprises him with a weapon in the leg. Sounds good from the couch but just don't work that way. Now, having said that, my Dad did exactly that "jammed it in gear and side stepped the clutch" when he was driving my brothers truck haul g bales. However, he was sitting idling while my brother was loading the bales, the truck was a 1982 LW 3406CAT (so 100% mechanical) and dad had experience with runaways before. Sitting at idle and the RPM suddenly started to climb FAST. Dad recognized what was happening g instantly and slammed it in gear in a nanosecond so it CAN be done but is VERY rare. Shaft on the turbo broke and the engine stared to feed on oil. 1 Quote Link to comment Share on other sites More sharing options...
BOBWhite Posted July 29, 2022 Share Posted July 29, 2022 If you have a clean garage and a buddy with all the specialty tools you could attempt to do it yourself. They're simple motors compared to what we have today but I'd definitely find some technical ligature on it. This video makes it seem real easy! If only in a perfect world in a nice clean shop with the motor out. Even if you have someone else do it this video really helps you get on the same page with your mechanic. Also does anyone know how to get parts from PAI? I'd imagine you would have to be a dealer or something but could you register an account for a farm or other small business types? Quote Link to comment Share on other sites More sharing options...
fjh Posted July 29, 2022 Share Posted July 29, 2022 11 hours ago, Licensed to kill said: Easier said than done. Unless you catch it, understand what is going on and react in the first couple hundred RPM, aint no way you are going to stab that thing in gear. "jam it in gear and side step the clutch" is like telling a cop to shoot the guy that surprises him with a weapon in the leg. Sounds good from the couch but just don't work that way. Now, having said that, my Dad did exactly that "jammed it in gear and side stepped the clutch" when he was driving my brothers truck haul g bales. However, he was sitting idling while my brother was loading the bales, the truck was a 1982 LW 3406CAT (so 100% mechanical) and dad had experience with runaways before. Sitting at idle and the RPM suddenly started to climb FAST. Dad recognized what was happening g instantly and slammed it in gear in a nanosecond so it CAN be done but is VERY rare. Shaft on the turbo broke and the engine stared to feed on oil. Exactly! I don't know how many storys I heard where by I was just going for a Shift AND Pop! When turbos let go! most times the compressor side would be popped in half! but the odd time the shaft would break and thats when shit can hit the fan in a hurry! they suck in some oil and the show is on! Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted July 29, 2022 Share Posted July 29, 2022 you can order PAI on-line, but not directly from them.. We have a parts store in Charlotte called "Diesel Parts" They stock PAI... I did see where you can try to creat a PAI Direct acct. But my Little Micro A$$ was not eligable.. The E-Tech I just did cost $6700.00 for the engine kit/ cam kit with all 18 lifters/ oil pump/ and cam bushings... I got 2 heads from Mack.. jojo 1 1 Quote Link to comment Share on other sites More sharing options...
fjh Posted July 29, 2022 Share Posted July 29, 2022 (edited) 4 hours ago, Joey Mack said: you can order PAI on-line, but not directly from them.. We have a parts store in Charlotte called "Diesel Parts" They stock PAI... I did see where you can try to creat a PAI Direct acct. But my Little Micro A$$ was not eligable.. The E-Tech I just did cost $6700.00 for the engine kit/ cam kit with all 18 lifters/ oil pump/ and cam bushings... I got 2 heads from Mack.. jojo But my Little Micro A$$ was not eligable.. Really ? I created and account years ago just so I could cross reference stuff ! was way better than the Volvo Turd parts setup! that said never intended on buy stuff! Edited July 29, 2022 by fjh Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted July 29, 2022 Share Posted July 29, 2022 I guess I should try again... Thanks "F"... jojo Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.