Need everyone to see this: Exhaust Gas Temperature Stuff.

[JMK]

Any tips for drivers that do not have a guage?

I travel on Hwy 93N over Bow Summit and up to the Columbia Icefields at least few times each month in my automatic L300.

During the day I keep a constant watch in my rear view mirror and if I see any hint of smoke I back off on the throttle. When the tachometer nears 2000 I hit the OD switch on the shifter and get the RPM's back up to near 3,000. If it gets back down to near 2000 on real steep pitches I'll slow down even more and shift down a gear. Luckily on these roads there is not a lot of stress from blocking following traffic, the ones in a hurry are rental cars with drivers you could care less about their quality visitor experience anyway, and it's almost perversly enjoyable slowing them down.

The problem is at night, I cannot see black smoke in my mirror. So I try to use the same pattern that I would normally use during the day. Day or night, I will also set the Turbo timer to somewhere around 3-5 minutes before I shut down after travelling these hills.

Any suggestions on how to improve things or what to watch for much appreciated.

[thedjjack]

You want the flame temperature as that is what will cause it to melt if pushing it...

I think 1400 is crazzzzzzzzzzzzzy hot... That will melt a Cummins 6bt

as for no gauge if you push the throttle more and no gain in speed you are making heat,,,lift the foot fast...

[Rattlenbang]

Any tips for drivers that do not have a guage?

I travel on Hwy 93N over Bow Summit and up to the Columbia Icefields at least few times each month in my automatic L300.

During the day I keep a constant watch in my rear view mirror and if I see any hint of smoke I back off on the throttle. When the tachometer nears 2000 I hit the OD switch on the shifter and get the RPM's back up to near 3,000. If it gets back down to near 2000 on real steep pitches I'll slow down even more and shift down a gear. Luckily on these roads there is not a lot of stress from blocking following traffic, the ones in a hurry are rental cars with drivers you could care less about their quality visitor experience anyway, and it's almost perversly enjoyable slowing them down.

The problem is at night, I cannot see black smoke in my mirror. So I try to use the same pattern that I would normally use during the day. Day or night, I will also set the Turbo timer to somewhere around 3-5 minutes before I shut down after travelling these hills.

Any suggestions on how to improve things or what to watch for much appreciated.

I think you are doing it right, if my own van is any indication. No matter what speed or load, once I see a bit of black, I back off. The black starts to show up right near 1200 post turbo. It's funny, after having driven gas vehicles so much, we are used to getting the most out of our engines with our right foot, while diesel engines aren't like that. It would almost be worthwhile to instal an adjustable stop so you simply can't push too much fuel into it. Once you are showing black, you're just wasting heads and fuel. Not sure why this isn't stock.

[Vanislpajero]

These were some great posts...I can see my truck has been running pretty hot compared to some of your vehicles and mine even has an intercooler. Cant forget that 2.5" straight exhaust....Even with these higher EGT's I've never seen my water temp go higher than normal...It always stays just a hair above the half way mark. Because of the coolant loss in my truck Ive been expecting a head or head gasket for months. I finally started to take it apart to diagnose it properly. I cant wait to see what I find


Keep posting up your EGT findings and your pyro locations

[Erebus]

I almost never see black smoke, except on start-up in the winter. So for me that isn't a useful tool. I have a 2.5" side exhaust, so I would see it. As others have pointed out, I do see smoke at night in the headlights of the car behind, but it is invisible in the day.

As for the exact temperature shown on the gauge, I very much doubt that my L300 has actually been running several hundred degrees hotter for the last 6 years and 100,000 km and it hasn't blown up yet. I think the various gauges are wildly inaccurate. The needle movement probably accurately reflects the exhaust's increase/decrease relative to seconds or minutes before, but the numbers from one gauge to the other vary greatly.

There is no way the temp from an EGT that is pre-turbo on one L300 is registering 300 F lower than a post-turbo on another. Most sources seem to feel that a turbo drops the exhaust temp by about 200 degrees (the heat gets transferred to the incoming air). So that would indicate a 500 degree actual difference. Seems highly unlikely to me.

My 3 cents worth.