'05 Granite fuel burning pig

[Supertrucker]

I seriously need to find a solution here. We have an '05 CV713 with the AI370 and its awful. Set up as a tandem dump pulling a tandem pup. When loaded, have to make shifts at 1800 otherwise it falls on its face. Has 14K front and 38K rears running 11R 24's. Best mileage I've gotten was 4.6 but only under perfect conditions with no wind and low 70's outside temps. It's on it's 3rd fan clutch as it seems the fan is controlling the temp. Been to the dealer and they say the fan is running normal duty cycle. I have a hard time believing that the fan should lock up every 53 seconds on average, more if bucking a wind. Engine temp climbs to 205-210, clutch locks up and drops to 180-5, then slowly climbs back up. It does not have a boost gauge so I have no idea where the turbo is at. I recently cleaned the oil cooler screen and that solved the overflow puking problem but did nothing to improve cooling. We flushed pulled the radiator and flushed with a pressure washer and that did help a little but didn't solve. My dad's from the old school and is convinced its a cooling problem or a fuel filter problem. I tend to think it's a power problem. It runs fine in the early spring and late fall when average temps are down. In a head wind you may be down to 53 mph. I've read all the posts and have not found a good direct answer. Please help if you can.

[lucerne tractor]

Do you have a variable pitch turbo? VGT controll? I have a 2005 460P that I have been working on for a year and, knock on wood, I think I got it. It pulls to 1200 and I shift at 1600 to 1750 according to the terain. If you got the same type engine I can give you a list of my problems and cures. Do you have a dash computer that tells you what the lightning bolt codes are?

[lucerne tractor]

Last qtr fuel tax 6.90mpg

[slpwlker]

What kind of weight,Terrain are you running. Also gearing. That 370 might be working it's ass off. Also sounds like a road tractor converted to a dump as light spec'd as it is

[wastenafarmtrucking]

2 gauges that I won't drive a truck with out are a boost gauge and a pyrometer. A boost gauge is like $25 and simple to install, the pyro kit is around $200 and may require a new head pipe, but well worth the cost considering the damage that can be averted and the fuel savings that can be obtained by using the two together.

[slpwlker]

2 gauges that I won't drive a truck with out are a boost gauge and a pyrometer. A boost gauge is like $25 and simple to install, the pyro kit is around $200 and may require a new head pipe, but well worth the cost considering the damage that can be averted and the fuel savings that can be obtained by using the two together.

Very true. My boost gauge dies I think I would be lost. Also Pyro. had problems with it but nothing lately

[lucerne tractor]

OK, don't have much to go by from your post, rear end gears, turbo boost, exhaust temp,do you have a computer on the dash to display problems when the lighning bolt comes on?

Anyway. The charge air coolers are known to crack, look for black along the edge or anywere on it. Plug it and test it at 35 lbs. It should lose no more then 5 lbs in 30 seconds. No,sometimes you don't hear it when running. I was losing 35lbs in 5 seconds, I heard no difference when fixed but I felt it. Second, there should be a small changable screw on filter between the compessor and the vgt controll. This filter oil from the compressor air and keeps it out of the vgt control. Mine was completly removed, maybe because of the cost of the filters, $60.00 at Mack. The shop in NC found it or found lack of it is more like it. This send all kinds of crazy signals to the turbo when it has oil in it, my truck would lose power, fall on it's face, run great, run fine, run so bad I had to shut down and restart to clear the computer. They installed a new filter system and a new vgt controll. Run your hand around the seam were the turbo bolts to the manifold,if you feel any air pushing your hand away, the square metal gasket is blown out and your not getting full boost. Are you changing the centrifical oil filter? It's in the upside down looking round top, black plastic thing you pour the oil in, it has a bolt down the middle. You should hear it spinning when you shut down.If it is not it is clogged and the oil is bypassing, the flow is restricted and the oil cools the engine too. There is an update on the thermostats, there are two and adding a bypass is part of the update I believe. Check that out for cooling. When all above is working, have the ecm updated by having the shop call Mack and Mack send them the updates, including the marshmellow pedal update 12B.Hope this helps.

[Supertrucker]

Thanks for the replies. I can't remember the rear gearing and as far as I know it's always been a dump but originally from Missouri, now in MN where it's flat as a pancake. When we got it, we put the pintle plate on for the pup. It does not have the in dash computer but it does have a pyro that typically runs around 800-850 degrees under load. I'm usually grossing right around 79-80,000 with the pup on. Without I can only legally axle 50K. With no trailer on, temps run fairly normal although you still need to shift at 1750-1800 otherwise it falls on its face. Today bucking a wind at about 80 degrees outside temp I averaged 3.5mpg. As stated before, at best I can get 4.6 with the trailer on under perfect conditions. I don't run without the trailer too often but if I do, it will get up to 5.5 mpg. I agree it's setup all wrong for a dump at least under MN laws.

[Supertrucker]

Oh it also does not have the vgt turbo. We have an '05 vision that does and that's been to the dealer many times. Most recently for another turbo, cracked manifold, cracked cooler among other problems.

[wastenafarmtrucking]

under a hard pull the pyro should climb to over a 1000deg. sounds like you're not getting enough fuel, you need to install a boost gauge and see what kind of boost you're pushing.

for example, when i hauled the first load with the Acar I just bought, I noticed it fell flat on it's face, since I had installed a boost gauge and a pyro, I noticed that the boost wouldn't go over 16lbs and the pyro ran at 700deg most of the time. The only way to get it higher was to lug the engine down to 1200rpm and hold it to the mat. It also was a pig on fuel.

Had the pump turned out 4 turns, now it will push 22lbs boost and run around 900deg climbing steadily in a hard pull. better on fuel and only puffs smoke on up shifts.

Of course a mechanical engine is easier to do that than a computerized one, but the workings of the two are the same.

Check the air to air, change the boots and clamps on the air to air tubing and have it put on a computer and check what the settings are, and put in a boost gauge.

[bts-4120]

sounds like it needs hotter file or injectors. alot of people have the same problem with a AI motor. and they have to have lower gears 442 or 464 to pull well

[Supertrucker]

Yeah I have a feeling the way it's set up that the final gearing is taller than it should be. It does have the T310m trans which I do like for the kind of work I do. It has not had the step 12B update, which it needs as the throttle response sucks and it stumbles sometimes. I'm real surprised that there's not more aftermarket programming support as there is for diesel pickups. You wouldn't think the maps would be all that difficult to adjust using a laptop. Since the mileage already sucks, adding more fuel shouldn't hurt. Those that have installed an aftermarket boost gauge, where did you plumb the sensor? Anyone have pics?

[slpwlker]

I would probably look into if it is possible. Get it turned to a 427. maybe alittle bigger. A bigger engine works less and since it is not working as harder as the smaller engine it uses less fuel. Just have to drive sensibly not keep your foot in it. My Cat in a hard pull even lugging down with the new turbo gets up to 900. With the old turbo I had to back out of it in the hills it would climb up to 1000 and better if I wasn't watching. Boost 2 different engines but putting around 38psi myself.

[41180]

ive heard the 370s and 400 ai with the 10 speed is not a good setup, of coarse rearend gear ratio is everything. ive found macks with 4.42 and 4.35 and 4.30 gears will over achieve while the 4.56 4.64 and 4.73 are pigs

[Supertrucker]

I'm guessing it's geared tall. Should run the vin and find out for sure. It'll run up to 80 empty with no wind but it's screaming at around 2100rpm. I'm not really concerned about fuel economy as I am about a little more power. I don't expect that much for our trucks since we're doing a lot of gravel running and off road work anyway, but I think a good running e6 300 or 327 would put me to shame.

[wastenafarmtrucking]

boost gauge uses a 1/8" air line usually, I've also plumbed them with 1/4". whatever works best.

find a plug in the intake manifold, (should be a 1/8" plug) install a compression fitting, run the line up thru the firewall and find a place on the dash where you want the gauge.

most macks have extra hole in the dash for extra gauges.

hook everything up and your done, usually takes 1/2hr-1hr to install.

[Mackpro]

The worst truck we ever sold was a new CV with a AI 400, Fuller 8LL trans, 4.17 gears and tall 24.5 tires. We almost had to buy it back. if your gonna run tall rubber with a AI engine , you better have atleast 4.42 gears. 4.64 gears pull good but limit your top speed and burn alittle to much fuel. Mack paid for a few rear gear changes here at our shop due to unhappy customers back in the early AI days. My good friend has a 05 CV tri-axle with a 427 AI with a 8LL, 4.42 gears and tall 24.5 tires and his is about right. It will do 79-80 MPH and pull good. We have done all the software updates+ a special Austraila engine file. Our next step on his truck is a full 5" exhaust with a high flow muffler. I think his turbo is about to go out so were ready with a 460 turbo and 460 HP download. We are also going to try a fuel cooler before summer hits.

[wastenafarmtrucking]

Why change a 427 to a 460? The 427 will out pull a 460 all day long.

The company truck my Dad drove was a CH day cab, 427 and a 10spd, 3.55 rears. I had a Vision, 460+10% and a 13spd, 3.73 rears.

With pretty much equal loads, his mite have been a little heavier, he would completely leave me in the dust on a hill. Every time, every hill.

[GearheadGrrrl]

First off, this is a vocational application with presumably no aero aids, etc., so 5 MPG at 80K GCW wouldn't be unexpected. Second, are you sure it's a 370 HP rated engine? Might be only a 300 and the used truck salesman BS'd!

[oilburner]

I don't know but that kind of mpg is about right for a local truck, my 237 only gets about 4.5 with 5.13 ratio and a six speed and gross around 68,000. Top speed is 57 mph but it holds it's on when you hit the hills the little engine does seem like it burns a lot of fuel but it is running hard all the time with the gear and the big gap six speed, your either got her toped out or pulled down hard waiting to make a shift, so I would say that has a lot to do with the mpg. I was using a 98 with a e7 454 and it got about the same 4.5 but it had a 2130 trans with 44 rears and 4.17 ratio with low pro 24.5 and it done a good job pulled over 100,000 lbs with it no problem. Good luck hope you get her going good

[rsb502]

The ai370 and t310 with 4.64 gears works great here in tn, in an 05 granite buy the factory boost guage it fits right in the dash and just plugs in then you have mack activate the boost guage in the ecm and your done and its all factory. I put the boost, suspension press guage in my 04 its very easy yo take the guage cluster loose lean it out and pop the halves apart and the guage just plugs right in. You definitely need any available updates for the ecm after I got all of them done on mine and argued with the guys in pa they sent a new program for my ecm and the truck out pulled an ai460 on a long hill that afternoon. There is an o ring in the intake manifold adapter that goes bad and leaks boost start the truck and idle it up to about 1000-1200 rpm and use a spray bottle to spray water/ dish soap mix onto all of the charge air connections you'll get bubbles at a leak. Id bet on a combo of ecm updates and boost leak repairs will fix it.

[Supertrucker]

Thanks 84superdog for thoroughly reading the post and the answer you provided. As stated before it is a vocational truck set up as a tandem dump pulling a tandem pup. It does get unhooked and run straight occasionally depending on the job. I'm not that concerned about fuel economy and only called it a fuel burning pig because it does not put out the work it should for the fuel it burns. We've put 2 fan clutches in at a cost of around $900 each and have pulled and flushed the radiator and the cooler, yet it still heats up when the pup is hooked up and loaded. Because of the light axles and the fact that it will run 80mph on a long run on a perfect day, I'm pretty sure it's geared tall. And yes, I'm pretty sure it's an AI370 judging by the tag on the valve cover.