I just installed an autometer EGT gauge in my 2002 6.0l gas chevy. I installed the probe about 1.5" from the head on the exhaust manifold. I made sure that the probe tip is close to the middle of the exhaust path.

When I first turned on the truck after sitting off all night, the temp on the EGT went straight to 750 to 800 deg. I read a lot of temp ranges on other sites but they were all in ref to diesel engines. They suggest 300 deg at idle. I checked the probe and at idle it is at 15 mv, which auto meter says is correct for what the gauge is reading.

Is this a normal temp???

 

I read the same with cats, and about 100* less without cats, both readings at idle.

 

I just took my truck for a drive and this is what I found.

Idle - 800 deg
normal around town driving - 1200 deg
highway at 2400 RPM - 1300 deg steady
full throtttle run - 1500 deg

These all seem high. Can someone give me some tips on how to get them down!!

I have a 6.0l chevy with STS turbo 5 psi boost and Nelson tune.

 

There are a lot of factors that change EGT readings from engine to engine. EGT can be a excellent tuning tool, but you have to set a base line first. I run a digial EGT on my 800cc twin 2 stroke snowmobile, it has two probes each mounted in the y-pipe 100mm for the piston face. On a 2-stroke the most power is made at 1200-1250F (rule of thumb only) and detonation starts at 1290-1330F. But my sled runs at 1300-1380F in the midrange with no problem. So to set the baseline I need to jet the carbs to the plugs and piston wash (the amount of carbon washed off the edges of the piston by the fuel entering at the transfer ports) and once I know the wash and plugs read good, then read the EGT temp, now this temp will be the baseline temp. So say 1300F is the baseline, any lower it will run running richer with less power, and any higher and it could meltdown.

my sled readings (2002 Skidoo MXZ 800)
idle 750F
low throttle 900-1050F
mid range 1250-1350F
WOT 1150-1250F

I don't think your readings are way high, because a 4 stroke runs leaner and doesn't have the unburned fuel exiting the exhaust like a 2 stroke does. Plus if your probe is located near more then one cylinder it would read higher.

 

Diesel and gas have very different Exhaust Gas temp readings. When tuning with an EGT it is a good idea to run a wide band along with your EGT and get an idea of what temp means what in your setup. As was said earlier, exhausts with and with out cats have some variation (extra heat from light-off and also backpressure) and as such, optimal EGTs need to be tested.

 

... not high at all. I ring the buzzer (1650*) on full throttle runs.

 

EGT is a reference. It is not something that is quantitative.
Each set up will be slightly different so its sometimes hard to compare different tucks, with different mods, in different environments, with different EGT gauges, probes, and probe locations. How the EGT rises as you abuse your truck is more important than start up temps. I have sat and watched the EGT gauge on some turbo cars climb to the point that metal will melt.

 

[quote]Idle - 800 deg
normal around town driving - 1200 deg
highway at 2400 RPM - 1300 deg steady
full throttle run - 1500 deg[quote]

I have a similar setup (6.0L with a procharger that hits 9psi) My EGT's are exactly the same as what you are seeing.

 

Thanks for the feedback!!!