jokerl90

Ok, thanks again. I don't have a boost guage on the dash. This truck has been a problem child at our company, the mechanics hate it and just about refuse to work on it, so I'm trying to figure things out on my own.

Thanks for the reply Wheeler. So if the temp sensor was giving a low or no voltage (open), would it cause the motor to use more fuel, low mpg, and lack pulling power on hills?

Well, I don't drive the truck by the guages, I do have to look at the road every once and a while.... Using the numbers from the tach gives a reference. Don't think asking, do you guys downshift when the motor makes a chugga chugga ping sound or when it's a ping ping chugga sound, would get me too far. This truck is very quiet and smooth. The only time I can tell a difference in the motor is around 1100 rpm . Thats just too low, or is it? The last time I had it at a Mack dealer, I was getting 5.4mpg, I thought it was low, the mechanic said the best you could get on these motors was between 5.5 or 6mpg. I may have the answer about the low mileage. Asking that question in another thread. Truck seems to like 1300 a little better than 1400, to me anyway.

2006 AC 427 engine I'm getting a blink code 3-1 which is exhaust temp sensor voltage high/low/open. Does this sensor give input to the engines computer or just drive the dial gauge in the dash? The gauge doesn't move at all. Thanks

Thanks for the replies! All I could find, including the sticker on the visor said 1200. 1400 made a real difference, gonna try it for a while. I'm wondering about fuel mileage, will see if the 1200 vs 1400 makes a difference for good or bad.

2006 CH600, 427 AC engine (recently rebuilt), Eaton 10 speed. Usual gross weight between 78,500 and 80,000 When pulling a hill, is it better to downshift at 1200 rpm or 1400? The story I have been downshifting at 1200 when pulling hills. Trucks with 350 Cats, even ones that have been turned down,castrated, will just walk by me on hills (same loads,trailers.etc.). On flat land, the truck I drive will fly, would do 80mph all day long if I let it. It also gets pretty crappy mileage, like 4 or 4.5 mpg. This truck is famous at our company for being a "fall on it's face when it see's a hill" POS. Yesterday, running with a buddy, he says start downshifting at 1400 even 1500 if it's a real hard pull. I started keeping up with him a lot better. Have I been wrong???? Is it meeeee??????? hahaha Thanks

Mack CH600 with a Eaton 10 speed. Truck has about 350,000 miles on it. Is it normal to hear some whine out of the transmission? Can hear it in the high side, but it's not "screaming" or anything like that. Just got in the truck and looking to cover my butt if necessary. Thanks.