Thank you for visiting HeavyEquipmentForums. 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. Just a thought if you haven't pulled to check those sensors Jeff. If no one else answers and you want by the book let me know but it will be tomorrow. Idle will then fall to 500rpm.
I can copy the exact procedure from my book for you, if you want to give it a try? I can't find that list anywhere on the web. 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've not stepped foot in my local Mack shop in better than two years since all my troubles. If you have a non-typical flywheel it should be replaced. I wiped the sensor clean and put it back in and the jumpy idle went away again. It's hard to wire in being it's against a board, but better than continuously replacing the stock switch.
If you need a pic of this box on my truck, just let me know and I'll take some for you. The pinless yoke Figure 1 is self-leveling in operation and does not have a yoke leveling adjustment screw. They pulled the engine down front geartrain included , and replaced everything bad. You need to find the valve set marks on the fly wheel peep hole at the bottom, also your engine will have a slack spot where the dynatard lump is I beleive there is a small depression at that spot to allow the slave in the rocker to charge your probably landing on that spot,Seting on valves rocking is not the best on these engines. It also is the final code in the list.
Might be worth checking that. I replaced the Baldwin oil and fuel filters with genuine Mack filters and have zero leaks so far today. The first 4 tell you there is a pointer in the center of the hole, at the bottom of the flywheel housing, after you remove the cover. This will be your new idle speed. If there is already a second plug in the head, removal of the head must be done. I hope they would've cleaned the metal from the sensors at that time but :beatsme Might be something for me to check.
Yup thats normal as I explained The dynatard will make some valves appear loose your good to go! Locate the cup plug that has the external leak by visually examining the plugs or, if necessary, performing an engine oil dye leak test. The little push button one burns out. Next tractor will be different with 550 or 600 Cat. Two other new one is having computor problems. Says that's a sure sign of a bad one and it will wreak havoc on the electrical system will random phantom electrical issues. Dealership could not get it to not do it either, but told me some Macks just have this problem. He said that when that thing goes out or cracks internally, you will experience all kinds of wacky things.
The pinless yokes are used for the inlet valves only. It'll be a two digit , with a slight pause between seperate codes. I hope they can find the reason and fix it for him. Other than that, it's a very nice, clean truck. We have had turbo prlblems, oil leaks, electrical, and whatever else. I pulled that one last night and wiped some small metal fragments and it seemed to improve the idle. I did try and calm my idle down using this technique, but had to raise or lower the rpm too much to find a calm spot.
Two other new one is having computor problems. No problem only 7 and a half pages. Oil temp is down now and I can honestly say this truck is starting to grow on me. If so, Sorry for the mis-information Serve, and others. If you need a pic of this box on my truck, just let me know and I'll take some for you. It used to be a Warrior Express sleeper truck that was chopped into a day cab. I have to travel 180miles south to another Mack dealership now for any work my regular independant shop can't do.
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. The sensor is located on the passenger side front by the timing gear area. Next tractor will be different with 550 or 600 Cat. 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. You're right though, Mack should've fix them, and under warrenty.
They pulled the engine down front geartrain included , and replaced everything bad. Write done the firing order. Then rock 5 and adjust 2, etc. I also took a pic of another common Mack fix. There's a junction box located right next to what looks like a starter relay on the firewall. Allow the sealant to cure for at least 20 minutes. You are actually pointing to the box that I am referring to in your second pic.
Looks like someone tried to shove some silicone in there to fix it but it didn't work so well. He said that when that thing goes out or cracks internally, you will experience all kinds of wacky things. Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. Sorry for the late response and thanks for pics. I hope they would've cleaned the metal from the sensors at that time but :beatsme Might be something for me to check. At just over 200k miles I lost 3 lobes off the cam from cam followers seizing.