Community Forums

GBDTN · 03-11-2018, 11:26 AM

After driving for several hours and stopping, I monitor the temps of my tires and bearings while in general check my coach and toad. I have been checking my turbo with an inferred temperature gun. Also monitor my intake air with a scan d which runs about 115* at air temp at about 60* outside. In the first minute of getting outside to spot check the turbo above the outside batteries, it starts at about 375 to 400* and after about 4 minutes of idle will drop to almost 200*. (I usually high idle)(coach water temp 188*) (((With air temps between 90*+ the first reading will be close to 500*))
Do these temps seem to be inline to you?
2004 C7 350cat
Tires about 25* over ambient temp
Transmission about 135* normal driving Hillbilly Interstate
Set cruse at 58 to 60mph

BFlinn181 · 03-11-2018, 02:02 PM

In general, those numbers don't sound out of line. Problem is, the exact temperature readings can vary with location. The turbo takes in outside air and compresses it, raising it's temperature, then runs it through the inner cooler. The turbo also takes exhaust gases from the exhaust manifold before they go out the muffler/exhaust pipe. The infrared thermometer aimed at the exhaust half will be much higher temperature than the compression side.

It's good that you use a fast idle cool-down period, especially after coming off the highway. I'd drop the idle after a few minutes and finish the shut down at a lower idle. Tire temperatures should be close to each other, the only variation should be explained by sunlight.

WILDEBILL308 · 03-11-2018, 02:04 PM

Quote:

Originally Posted by GBDTN

After driving for several hours and stopping, I monitor the temps of my tires and bearings while in general check my coach and toad. I have been checking my turbo with an inferred temperature gun. Also monitor my intake air with a scan d which runs about 115* at air temp at about 60* outside. In the first minute of getting outside to spot check the turbo above the outside batteries, it starts at about 375 to 400* and after about 4 minutes of idle will drop to almost 200*. (I usually high idle)(coach water temp 188*) (((With air temps between 90*+ the first reading will be close to 500*))
Do these temps seem to be inline to you?
2004 C7 350cat
Tires about 25* over ambient temp
Transmission about 135* normal driving Hillbilly Interstate
Set cruse at 58 to 60mph

What you need to get an accurate temperature is a Pyrometer before the turbo. There are several Exhausts Gas Temperature gages available (EGT).
The problem time can be when you are pulling hills. If you see hi temps you can adjust by lifting on the throttle or down shifting to reduce load or a combo.
Yes it is good to let your turbo cool before you shut down so you don't coak the oil in the bearing passages in the turbo and clog them up.
Bill

saddlesore · 03-11-2018, 02:10 PM

Quote:

Originally Posted by WILDEBILL308

What you need to get an accurate temperature is a Pyrometer before the turbo. There are several Exhausts Gas Temperature gages available (EGT).
The problem time can be when you are pulling hills. If you see hi temps you can adjust by lifting on the throttle or down shifting to reduce load or a combo.
Yes it is good to let your turbo cool before you shut down so you don't coak the oil in the bearing passages in the turbo and clog them up.
Bill

ISSPRO Pyrometers are what I have used for many years on an 18 wheeler.
The temp sensor (thermocouple) mounted on the exhaust side of the turbo..(NOT the "hot side" turbo to engine)....(Diesel engine with turbo) pulling hard you should try to keep the temp under 900 deg.
and Yes cool down for a minute or three is strongly recommended..

WILDEBILL308 · 03-11-2018, 05:22 PM

Quote:

Originally Posted by saddlesore

ISSPRO Pyrometers are what I have used for many years on an 18 wheeler.
The temp sensor (thermocouple) mounted on the exhaust side of the turbo..(NOT the "hot side" turbo to engine)....(Diesel engine with turbo) pulling hard you should try to keep the temp under 900 deg.
and Yes cool down for a minute or three is strongly recommended..

Yes that is how some people use to do it. It is now considered best practice to mount your Pyrometer where the heat is, on the exhaust manifold before the turbo. I had an article where they did test with probes in both places. The hot side would be as much as 500* hotter than the exhaust side.
Bill

Cat · 03-11-2018, 06:12 PM

All look normal.

1doodadd · 03-11-2018, 08:02 PM

Quote:

Originally Posted by GBDTN

After driving for several hours and stopping, I monitor the temps of my tires and bearings while in general check my coach and toad. I have been checking my turbo with an inferred temperature gun. Also monitor my intake air with a scan d which runs about 115* at air temp at about 60* outside. In the first minute of getting outside to spot check the turbo above the outside batteries, it starts at about 375 to 400* and after about 4 minutes of idle will drop to almost 200*. (I usually high idle)(coach water temp 188*) (((With air temps between 90*+ the first reading will be close to 500*))
Do these temps seem to be inline to you?
2004 C7 350cat
Tires about 25* over ambient temp
Transmission about 135* normal driving Hillbilly Interstate
Set cruse at 58 to 60mph

Your Good To Go. Nothing to Worry About

saddlesore · 03-11-2018, 08:03 PM

Quote:

Originally Posted by WILDEBILL308

Yes that is how some people use to do it. It is now considered best practice to mount your Pyrometer where the heat is, on the exhaust manifold before the turbo. I had an article where they did test with probes in both places. The hot side would be as much as 500* hotter than the exhaust side.
Bill

Correct.. HOWEVER..Those have not have an end of the thermocouple melt and fall off...directly into the turbo and then into engine...only took once for me to go back to the old school thinking.
(and there is about a 300 deg difference from the hot to the cold side of the turbo,so you just do the mental math....)

GreaTOne65 · 03-11-2018, 08:16 PM

Saddlesore, you have got me to thinking, I installed my probe the same way on my MotorHome the same as I did on the tractors I had, before the turbo. That was the way the directions said to mount it. Now after hearing about the thermo couple melting, I may remount the one on the MH, because the C-9 in the MH has been at 1400 degrees a number of times, and I must tell you it is quite unsettling.

WILDEBILL308 · 03-12-2018, 08:19 PM

Quote:

Originally Posted by saddlesore

Correct.. HOWEVER..Those have not have an end of the thermocouple melt and fall off...directly into the turbo and then into engine...only took once for me to go back to the old school thinking.
(and there is about a 300 deg difference from the hot to the cold side of the turbo,so you just do the mental math....)

I have never had a problem with a probe melting when you use a correct for application probe.
Adding 300* is fine but now ware near accurate. Changes in your air fuel mix can drive your EGT 400-500* higher than your EGT after the turbo. So you are seeing 900 after the turbo and add 300 you think it is good at 1200* but if it is higher like the 4-500* you are in reality hitting 1300* or 1400* and not knowing it.

Bill

saddlesore · 03-12-2018, 10:41 PM

Quote:

Originally Posted by WILDEBILL308

I have never had a problem with a probe melting when you use a correct for application probe.
Adding 300* is fine but now ware near accurate. Changes in your air fuel mix can drive your EGT 400-500* higher than your EGT after the turbo. So you are seeing 900 after the turbo and add 300 you think it is good at 1200* but if it is higher like the 4-500* you are in reality hitting 1300* or 1400* and not knowing it.

Bill

What ever opens your pocket book..
You get up that high of temps your oil and water temps will be climbing...time to back out of it...
The last few generations of electronic controlled engines the computers will reduce the fuel pressure and or other ways to "protect" the engine...That is why most of them do not have a pyrometer.
I'll just stand by my experiences...

WILDEBILL308 · 03-13-2018, 11:03 AM

Quote:

Originally Posted by saddlesore

What ever opens your pocket book..
You get up that high of temps your oil and water temps will be climbing...time to back out of it...
The last few generations of electronic controlled engines the computers will reduce the fuel pressure and or other ways to "protect" the engine...That is why most of them do not have a pyrometer.
I'll just stand by my experiences...

This once more shows you are just talking. I can demonstrate that you can have dangerous EGT temps and the water temp doesn't move. Keep in mind you have to heat all the water before it shows an increase on the gage.
You keep believing what ever you want, I don't have to pay for your repairs.
Bill

GreaTOne65 · 03-13-2018, 11:57 AM

Wildbill is right, I know this from experience. We had a tractor that would blow the engine, and the water temp never read anything but normal. The other tractors we had the water temp never got off the normal reading, even though the pyrometer was showing it was working very hard. The Beaver I'm driving now shows the pyrometer at extreme temps but the water temp is normal. The only true way to know how hard an engine is working is by the EGT.

saddlesore · 03-13-2018, 12:10 PM

Quote:

Originally Posted by WILDEBILL308

This once more shows you are just talking. I can demonstrate that you can have dangerous EGT temps and the water temp doesn't move. Keep in mind you have to heat all the water before it shows an increase on the gage.
You keep believing what ever you want, I don't have to pay for your repairs.
Bill

Whatever..You Win..YAY for you.
I speak from 50 years and over 5 million miles under my butt. owning 18 wheelers, both stock and not so stock engines, hauling high/wide & heavy and super loads..
Good Day to you.