Mackpro

I wonder if the VGT/wastegate is sticking. Take the stainless braided air line off the turbo actuator (VGT/wastegate) and lightly blow air into the wastegate and see if the rod moves down full stroke then springs back up when air is removed. The pivot pin can sieze up and the turbo will not work correctly. The pivot pin can be removed and cleaned and coated with hi-temp anti seize. An "E" clip holds it in. You might have to shoot a little air in the VGT to get the pin in and out. Dont put to much air to the VGT or you could blow the diaphram in it. I dont think the lower HP engines had the boost pressur relief valve in the intake manifold piping.

There is sometimes a "L" shaped bracket that goes from the cylinder head to the water pump housing. If this is missing it causes the assembly to vibrate and crack the water pump housing. Last 6 of the vin and i can maybe get u a parts pic and see if it wass equipped this way.

Our sister store sold a local fleet 15 CXU's with the MP8 and M-drive's. All the top drivers who are mostly oldtimers did not want to get out of their older CXU's with manual trans and climb into the new CXU's with the M-drives. Lots of bitching and groaning but the boss said just try them for a week. I not lying but the owner of the company/fleet said after a week , 100% of the drivers said to pass their older trucks on down the line and that their not giving up their M-drives. We have had no failures of any kind with the M-drives. I know one very very large dealership that had to replace 2 but it was by Macks request and just a drop in the bucket of the number of M-drives he had running around there.

Look at the tag on the turbo and see if the part# ends in something like 631GC5171M***. Hopefully you have the newer 631GC5176M** series turbos. The 5171 series had some weird issuses with them. You rarely see them much cause the had a high failure rate and probably have all bee replaced. Check for soot leaking around the exhaust manifolds and the EGR piping as the EGR piping actually had turbo boost pressure on it when under a load. Make sure this thing doesn't have an exhaust brake on it under the cab. Check the muffler for a broken baffle , rattling around and sometimes blocking air flow through the muffler. 8-3 code is the #3 EUP pump and shouldnt cause the noise and whistle issue.

If under warranty send it to the dealer, otherwise throw parts at it. Extended warranties dont sound so bad after all (with these new engines). There are no troubleshooting books on the 07 emission MP engines and newer. The only troubleshooting guides are in the VCADS/PTT software that u can buy from a Mack dealer and put in your laptop. Sadly, with the MP engines, we dont even try to "fix over the phone" as it would take hours to explain and then without all the special tools and breakout boxes your wasting your time. With the older engines we could scan and fax pages out of the manual to the customer and help him that way but with the new stuff its impossible. By the way whats the FMI of the code and does the engine have SCR/ DEF injection on it?

Low coolant sensor fault, with the FMI of 3 its probably not low of coolant but looks mor like a electrical/ wiring issue or a bad sensor. Unplug the sensor and put a paper clip jumping the two wires together and see if the light goes out, hopefully it does , if not unplug both engine ECM connections and check for oil or antifreeze in the engine ECM and harness.

On top of the dash in the fuse box look at fuse # FU53 its a 10 amp and powers the compressor. Also fuse # FU72 powers the complete AC/heater unit. And also check FU25 as well ( its a square shaped fuse )

My buddies 2012 CHU daycab with no fairings, 505 HP, Mack 10 speed trans, rear gears are in the 3.40 range ( cant remember) just pulled a loaded van back and forth to StLouis at 68 MPH and he got 6.8 MPG. Boss man said he heard of MP-8's with super high rear gears running 13 speed trans and mostly running in 12 th gear but on flat ground going to 13th gear and the engine RPM dropping to 1100 RPM and getting some unheard of MPG. Not saying its true but thats what I heard.

The last RD688S I can find was built on 4/7/03 and labled a 2004 model. It did have a AI-350 ASET engine in it. However some of the other guys may have a better way of looking it up in the Mack mainframe.

I have seen alot that average 6.9MPG with and without wind farings. Keeping the MPH down is the key. None were equipped with a 13 speed though , Here we rarely see a 13 , 15 or 18 speed trans anymore unless in a GU.

Looks like on 4/12/11 a Mack dealer set up the step 12B downloads and new datafiles for the engine. Its shows the dealer downloaded the new files in their laptop but the dealer didnt send back the confimation file saying they were installed into the truck. Not saying the dealer didnt install them but who knows. It shows u have a fuller 8LL trans and 4.42 rear gears. Truck came with 22.5 wheels but no tire size listed. If your running full size 24.5 tires they might be to tall for your 350 HP. We sold 2 CV's with 400AI's, 8LL trans, 24.5 tall rubber and 4.17 gears. Almost had to buy them back from some very unhappy customers. The AI engine has a very tight window for every thing to work right. Any one thing out of wack/changed and its low power complants. The good thing bout the AI engine is to do HP upgrades you just need to change turbo and injectors and download. Older ETECHs you sometimes have to change the camshaft keyway. In your case you might need to upgrade to a air fanclutch as well.

S Here in the States the CCRS 460 has a wategated turbo and if you try to change anything or adjust the wastegate for more boost it will derate the engine when it overboost's past specs. The 427 HP CCRS's dont have this feature or the high$$$$ wastegated turbo. When customers come in for factory HP upgrades on a CCRS we usually steer them towards the 427 for this reason. We have actually turned a 460 down to a 427 due to the customer always swapping custom turbos and injectors.I saw a Detroit 60 series wategated turbo bolted on the exhaust manifold one day on that truck.

We only use Panasonic tougbooks in our shop. They are worth the money if they are used every day by different techs, They get rained on, dropped on the floor, oil spilled on them and thats on a good day. We have the Cummins Insight program which is awesome and of course the Mack/volvo VCADS/ PTT ( which everyone here hates with a passion) and we still use the old Mack software alot. For other trucks we use the Eaton MD-300 which works well on other makes and models of truck and engines and ABS.

If the FMI is 4 that means voltage low or open circuit. If your engine ECM is mounted up on its edge on the driver side of the engine, pull the top/J1 connector loose and check for antifreeze or oil in the connection. Wire number for the # 4 eup are EJ1-24-2.0 and EJ1-41A-2.0 . Which would be pins 24 and 41 in the engine top/J1 connector.

I really cant even remember much about that and the more I think , this actually might have be the VMAC2 E-7 engines ( before ETECH). Too many years, ex-wives and beers ago!

For a 1995 427HP VMAC2 the book says 24-32 psi is where it should be.

I think you have a MID-128 SID-4 FMI-4 code which is the #4 EUP injector pump. But not 100% sure if this is the code you are reading. How are you reading this code?

White smoke is normal on start up on the VMAC 1's and 2's as the timing advance is powered by oil pressure and of course when you first start engine it takes alittle while to get the timing advance moving. On the black smoke, everything on the turbo boost side. After cooler, intake manifold gaskets, dirty air filter. Black smoke is unburnt fuel, Either from to much fuel or lack of air/boost.

His truck is a ETECH style engine with no real injection pump but I know the copper washers you talk of on the older injection pumps, they now have a steel washer to take its place.

The check valve could be bad, its on the pass side of the block above the air compressor. The idle issues is probably that the driver hit the cruise buttons just right and lowered the idle speed, it happens alot, I always turn this feature off in the parameters to keep this from happening.

I would start with a fuel supply pump, unless it has been changed lately. I know we put alot on. We had a 06 CV in here yesterday that would barely run and that fixed it. Once it is running, does it have as much power as it did before?

I vote turn signal switch as well. I hope your style is not the kind that you have to remove the steering wheel to change the turn signal switch. I really liked the days of the old flat dash CH's where you could change the TS switch in under a minute with the right size torx screwdriver.

Not a single warranty claim in it's life which could be good or bad. Seems like a good all Mack truck with T-2180B trans and Mack rears with 3.86 gears and air ride, It came with a 64" mid-rise sleeper. Engine has Jacobs engine brake. If the cam had been replaced and the Jake pins replaced I would not be scared to jump in it and go cross country.

Early ETECH's did have camshaft issuses, intake manifold gaskets blowing out (around #1 cylinder) and Jake Brake (floating pin) issuses. All these problems can be fixed with available updated parts. A great engine!

We had one new 2011/2012 MRU in our area but customer sold it to someone in New York after 3 months of use. So glad to see it go!