Mackpro

The blower motor work but just no cold air??

I’d only been working at the dealership for a year when we got in the first CH’s , first one we got was built 8-29-1988 with a E-6 350 4 valve head engine. That Mayflower built CH cab seemed like a spaceship compared to the R-models then. Probably due for a major update as bad as I hate to say it.

I was a whole lot younger back in them days . I probably couldn’t do 2 cam jobs a week now , LOL. We used a toaster oven to carefully heat the gear and put it on . But removing the gear was another story . Getting it into the press was a challenge. Finally found that cutting the camshaft in two about a foot from the gear made it easier to get into the press with out damaging the gear. Otherwise we were wrestling into the press and usually dropping it or banging into anything with in a 3 foot radius. Glad those days are over for me .

I have recently heard on the Volvo side that a few crankshafts have burned out the thrust bearings due to a clutch actuator issue on the I-shift transmissions. Even though the MP/M-drive on the Mack side is exactly the same parts it has seemed to only have shown up on the Volvo side.

This is a pic of the new and improved timing gear cover . If you zoom in you can see the gussets casted in around the hole for the engine position sensor. https://www.finditparts.com/products/8549180/mack-25102069?srcid=CHL01SCL010-Npla-Dmdt-Gusa-Svbr-Mmuu-K8549180-L187&srcid=CHL01SCL010&gclid=Cj0KCQjwuaiXBhCCARIsAKZLt3ma4VK_xs26tnv330HtNuUevV9EkCOYowYOx-Ywtwe2M_W-TW2TCQ8aAh1jEALw_wcB

Your right on rarely seeing any wear on the cam thrust washer . Back in the ETECH days I had a couple of trucks that I was chasing the 3-4 code on . I kept getting different readings on measuring the timing cover to cam gear depth. I’d measure, then use the correct shims on the sensor and test drive and get a random 3-4 code active again. I’d come back and re-measure and get a different depth measurement. One of the old guys back then associated it with “Cam floating “ as he called it. Adding the .015” shim seemed to work. I was personally doing 3 cams jobs a week back then and now wondering if pressing the cam gear off with a 20 ton press could have slightly tweaked/bent the camshaft gear. This could explain different depth measurements depending on where the engine stopped spinning when turning it off.

Also the came out with a new thicker timing cover with gussets on the engine position mounting location .

If you are throwing the 3-4 code . I will attach the bulletin on troubleshooting that code. However the service bulletin you need on shimming the sensor is SB-273-004 and I can’t seem to find it . I found that on high milage trucks , the camshaft thrust washer would be so worn that the cam would float back and forth and come to close to the sensor causing the 3-4 code. I would add an extra .015 shim and test drive and see what happens. Also replacing the vibration damper with a larger one helps on some early ETECH. Early ETECHs under 400 HP had the smaller damper/balancer. I know all Aset engines had the larger damper. https://f01.justanswer.com/HeavyEquipmentTech/7977f3ec-83db-47e4-9d6a-f6babf391cd7_Mack_Engine_pos_sensor_bulletin45-sb221037.pdf

I just remembered responding to this question months ago and was thinking that possibly some parameter changes could fix the issue. I learned today that I was wrong . We have been using the Mdrive trans with great success for the last 2 years even with our feed trailers with the auger boom. 99% of the farms we deliver feed to it works great. However, one farm is laid where we could slowly spread over a larger area and speed up the process by doing this. And it does work while moving at under 5 MPH. However is almost impossible to keep it that slow without using the brake pedal. I never really thought about it but the brake pedal on a Mdrive is basically a clutch pedal too. Hit the brake pedal and the clutch actuator pushes the clutch in and of course the PTO stops spinning. We looked in the free online Mack Body Builder website and it recommended using the REPTO flywheel RTO with the MDRIVE or Allison transmission. While this is only a minor problem for us but I could see it being a issue tailgating gravel/rock in dump trucks.

The engine speed sensor on the flywheel housing usually will have no shims. But the book says to measure and shim if needed . The engine position sensor on the front that reads the camshaft will always have 1 shim or 2. They make .015 and .030” shims. Due to timing cover thickness difference and camshaft thrust washer wear it impossible to guess what shims are needed. I will try to locate the instructions and chart and post it here.

The only difference in the HP levels is in the program. Turbos and injectors and other engine components are the same regardless of HP rating. I’m not to sure on any tuners on the market . And I’m even more skeptical of the deletes being done locally. The 485 HP tri axles GU’s running around here coming out of the quarry at 80,000 pounds seem to have no complaints on power. The last GU’s and newer GR’s around here are all spec’ed with Allison’s and 455 MP’s and run with the older 485’s with no problem.

If EGR deleted I would not go above 445. Factory Export MP8 with no emissions are limited to 440 HP. We have several factory export 2016 Volvos running around here that have EGR only ( no DEF/DPF) and they are 465 HP. Don’t know how they got here but at least 10 I know of . You could have the dealership bump you to 485 if you have a Mack trans or one of the larger fuller trans , usually it’s really cheap.

To me it does. I also have access to the VOCOM 1 and 2 which I have to use with TechTool because if I’m not using VOCOM it limits some tests and programing.

I get ahead of myself sometimes.

MP8’s before DEF . Had HP ratings of 415, 425, 445,455 and 485. Torque output was 1540, 1560, 1660 or 1700. This all was mostly determined by if you had the Econodyne, Maxicruise or Maxidyne version . The 415C has more torque than a 445M 1660vs1650.

Has the emissions been deleted? If so , seen several trucks with valve issues. Mainly if the EGR has been deleted. Disregard, just noticed that FJH was ahead of me on the EGR delete issue

On MP8’s. Looking on the left hand side of engine. Look to the right of the engine ECM . There are two sensors screwed into the block at an angle, one above the other. The top one is the crankcase pressure sensor. Bottom one is oil pressure sensor. The part number has been updated several times due to high failure rate of early ones. This same part numbered sensor is used in several locations on the engine as fuel pressure sensor , piston cooling oil pressure sensor and AHI fuel pressure sensor. MP7 locations are different than the MP8.

As Onyx610 said , probably EGR system related /low boost

If your regen temps are getting super high like 950-1000 degrees and kicking the regen out then I would definitely be looking at injector cups being the problem. Just last Friday I had a 2015 MP8 that would not complete a regen and had high spot codes. During the regen I could see fuel pressure start to drop and temps shoot up . Number 5 and 6 cups blown , the injector sealing surfaces were pitted so I replaced both cups and injectors. Driver never mentioned hard starting but after failed regens the truck spun over a few seconds before starting

The VMAC 3 software diag is awesome. I used the Nexiq USB link 2 interface with good luck and now use the Noregon DLA 2.0 adapter mostly.

To really look into the ASET-AC engine you almost have to have the old VMAC 3 diagnostic program and get into the advanced diag screen where you can view the EGR actual flow and target flow, the turbo wheel speed, boost pressure ( running and key on/ engine off readings) throttle % and engine load . Of course a million other things to look at on those engines. Rocker arm hold down bolts , valve adjustment, turbo calibration, fuel pressure, boost pressure relief valve worn out. One day I need to write all this down .

I left the dealership and now only work on MP equipped truck but at least it’s fleet maintenance. We buy the max extended warranty on every part of the truck we can. It has saved the company lots of money. Surprisingly, the extended chassis warranty has helped out more than I ever thought it would. Getting little things like turn signal switches , HVAC components, dash clusters , seat belts, am/fm radios , wiring harnesses and door control panels covered out to 4 years did make it worth it.

After some research it’s a ASET AC-460E engine. Software updates were done a couple of years ago. The engine software was updated to the newest level but the VECU was updated to Step 12A which is OK but they should have bumped it to Step12B to get their money’s worth. Step12B has been out since 2007-2008. Of fuel pressure and boost pressures are good. Getting a dealership to install the 460P HP program might be worth it. If Mack Corporate will turn it on that is .

Back in the late 80’s one of the old guys I worked with was messing with a rough running E7 . He pulled the fuel filters which had been replaced trying to fix the miss . He poured out diesel. Then re-filled with half with diesel other half automatic transmission fluid. Within 5 minutes it was running like new . Not saying put ATF in there but looked like a miracle to me .

Awhile back we were able to get the inlet NOX sensors but not the outlet ones . Now that has reversed and the inlet ones are impossible to get. The dealership we get parts from heard yesterday from corporate that things are going to get worse. We did buy 4 of the Dinex outlet nox sensors about 4-5 months ago due to trucks down . 3 of the 4 failed but it got us out of a jam till the factory ones came in. The failure rate and issues caused by the aftermarket and counterfeit nox sensors was so great that Mack released a bulletin on how to spot counterfeit and aftermarket nox sensors. . As far as the boost leak , don’t take the rear EGR elbow pipe off unless you have a way to pressurize the intake system. You can actually make things worse. The elbow has a floating collar and is a extreme pain to get sealed. We have a tool that goes on the aftercooler and pressurizes it and the intake manifold which in turn pressurizes the EGR system and you can locate your leak. If it is the elbow connection , use new gaskets and clamps . You will find you will need to readjust the clamp and collar a few times between pressure testing to get it air tight. There has been times I’d wished for a super greasy clutch job than to reseal that elbow.