Strange EGT readings

[cowboywildbill]

I have twin Ispro EGT guages for left and right bank. The right side probe is installed into the rear of the exhaust manifold, typical place. The left side probe is in the pipe about 2 or 3 inches from the manifold, this was as close as I could get it. For months my left bank would read anywhere from 50 to 100 degrees higher when in a pull or hard exceleration. I was puzzled, because the probe is not in the manifold,and it read higher, but I guess the gasses travel at a high velocity and therefore wouldn't lose any temp drop. Or maybe the restriction in the left made it read higher? The left also reacted faster and climbed faster than the right guage did. When I would cruise, the temps would usually read pretty even. I have had the left guage go to 1300 while really hammering it with a fifth wheel behind on a bad hill while in level 2 juice, I just let off a little and it stays safe 1250 or less.I use rottella fuel treatment on a fairly regular basis. I just put a whole quart in for the first time, because they say it is a good idea every 10,000 miles or so to clean pistons and injectors. About 100 miles of running after treatment, and now my right side reads a little higher, and reacts quicker, they are closer in temp readings now through out the range of different driving conditions now. I am wondering if I had an injector that was a little fouled and didn't know it? I have 42,000 trouble free miles, and it always runs great and is smooth. I also change the fuel filter every 5,000 to 8,000 miles and drain it every week or two. And I have never seen any sign of water in the fuel. Although I am a bit parinoid about the problems with water that I hear about. A friend of mine had 83,000 miles on his dmax and had the dealer service it every time for all required maintance. His truck was running great and he took it in for routine service and they told him that one bank of his engine was shot because of rust in the lines. They wanted $4,000 to fix it and "NO WARRANTY". He traded it in on a new one. Any idea's on the change in my temp readings, and what is the best fuel additive to use? I am a little puzzled, maybe one of you tech or engineer types can shed some light on this. And how soon would you know that water screwed up your system? Thanks for the help. I didn't mean to ramble, but it is puzzleing.

[mark45678]

I agree that the drivers side will read higher mostly due to the exhaust manifold being more restrictive..... EGT temp probes dont last forever my guess is your probe is starting to fail..... or its posible that you had carbon build up that was cleard by additve but I find that hard to believe! You could drop your egt some by changeing the stock muffler out! a strait threw should drop your egt by as much as 150*f

[cowboywildbill]

Hi Mark, I agree with you that the driver side should read a little higher due to the restriction. But it is strange that for the longest time the drivers side read higher, and now the passenger side is reading higher. But then there is the argument that the temp is highest in the manifold. Sorry I forgot to mention I am running a banks 4" exhaust system & muffler. I wouldn't think that only running 100 miles with the treatment would clean anything that quickly ? But who knows? Thanks for the reply.