Exhaust gas temperature

[silverback]

In my Selene I have a Cummins 6BTA. 5.9 lt
She is equiped with exhaust gas temp sensor. It seems to read 2000degrees which I think is way too high. Actually the gauge shows 200 but is marked X 10. Has anyone an idea of correct temp under say 70% load please? I’m not sure where the sensor is in relation to turbo.

 

[Comodave]

I don’t have an EGT gauge on our boat but used to have one in a truck we added a turbo to. The usual range was in the 700 degree range and they told me to keep it under about 900. 2,000 seems way high to me, but I am not positive.

 

[jleonard]

If it’s reading 2000 then something is wrong with the sensor, wiring, or gage.
I had one with the sensor before the turbo in a truck with a 5.9 and I had to push it very hard uphill to get temps over 1200-1300.
Had one in a boat after the turbo and the 700 to 900 range stated above was where it ran.

 

[O C Diver]

At 2000 degrees I would expect steam to be coming out the exhaust and the engine overheating. The exhaust manifold is cooled by coolant circulated in the freshwater system. To reach 2000 degrees would likely generate steam in the exhaust manifold (in the coolant). If the engine is operating in the normal coolant temperature range and steam isn't coming out the exhaust, I would first look at the sensor or gauge. It should be pretty easy to check with an infrared temperature gun.

Ted

 

[ksanders]

In my Selene I have a Cummins 6BTA. 5.9 lt
She is equiped with exhaust gas temp sensor. It seems to read 2000degrees which I think is way too high. Actually the gauge shows 200 but is marked X 10. Has anyone an idea of correct temp under say 70% load please? I’m not sure where the sensor is in relation to turbo.

I have that same engine in my boat.

At <1800 I read about 600F

Once the turbo starts to kick in and you load up the engine the temperature goes to about 900.

It is also important where you read the temperature. The port on mine for measurement is right next to the turbo outlet. This is probably the standard or "normal" location for this measurement.

My EGT gauges use standard K type thermocouples. Youi can buy them almost anywhere and you can use a portable meter as a check gauge right on the thermocouple leads for troubleshooting.

 

[sunchaser]

A heat gun is your friend when questioning gauge temperature readings. Above normal accurate EGTs can be a sign of engine over loading, often due to wrong (too big) a prop. Highly doubtful this is your issue unless you've just changed props.

 

[Delfin]

2000 degrees isn't likely as steel would be plastic at that point. Melt temp is only 600 degrees above that. Delfin's downstream EGT ranges from 400 - 875 at WOT.

 

[psneeld]

Input from a friend....

"If the EGT gauge reads 2000 and never varies it is because there is a fault in the circuit somewhere, usually an open thermocouple.

A short in the thermocouple leads will show the temperature at the location of the short, an open will show maximum reading.

Not knowing the type of TC used or the type of amplification or metering leaves several other possibilities. More information is required to troubleshoot."

 

[Greg QS]

You most likely have a failed sender. If you were pushing 2000deg you are at meltdown temps.

From the SBMAR web site. A great resource . Tony Athens

"If you look at all of the various 6BTA models rated from the early 300 ( CPL 970/1613) thru the latest CPL 8457 (370 Diamond), published EGT’s run from about 850F thru 920 F at WOT/full engine loading. Remember, these numbers are taken is certified test cells and are there for a guide..

Engine room conditions are far from test cell conditions as to everything that affects engine performance, and these engine specs are on NEW ENGINES..

Field experience has told me most installs run higher than these specs– May 25F-100F and still to me, this is normal.. And something running below WOT can product higher EGT’s than at full RPM–Lot’s of variables in how each boat can load an engine.

So back to your question– Maybe once the vessel is on a clean plane at 2000-2400 RPM–900-950 F-ish? Running below 900F is always a good thing, but very “propped out” early B’s do that.

How long have been watching the EGT? An established base line is good when all is in good shape & up to spec, especially the aftercooler and the turbo..A turbo that has been eating saltwater just about always lowers boost and raises EGT. A dirty aftercooler also does the same."

 

[C lectric]

Replace the thermocouple. PSNEELD has it right. THe sensor circuit is open, One of the wiring leads is broken somewhere..

 

[silverback]

Exhaust gas temp

I had it wrong. Side benefit of old age!It actually shows 200c but either way it is incorrect. So I shall start the investigation. Thank you all for your help.

 

[Delfin]

I had it wrong. Side benefit of old age!It actually shows 200c but either way it is incorrect. So I shall start the investigation. Thank you all for your help.

May not be wrong. That is 400 F, which is certainly possible. If at WOT it reads 400 - 450 C, it's likely working fine.

 

[SeaMaster101]

@silverback If you have NMEA2000 network the best solution will be to replace the old one with one of these:
https://acrossoceansystems.com/index.php/product-tag/egt-monitor/
And display the value on your MFD screens

 

[Max1]

I purchased an EGT and installed it on my Lehman diesel 120 based on recommendations from Seamoose here on Trawler forms.
The exhaust elbow on my Lehman 120 was already tapped for the EGT sensor. I just removed the plug and screwed in the EGT sensor. When running it has the raw water blowing over it mixed with the exhaust so it reads cold. The idea here is if you're raw water impeller falls apart, or you get a blockage to your raw water system, EGT will rise quickly before any damage to the engine occurs. Haven't seen mine move off of cold since installing it.

I will have the opportunity to test it this spring when I run the engine on the hard. I do this with the impeller removed to prevent wear. When i run on the hard, i keep my eye on the engine gauges and shut down the engine before it reaches full operating temperature.

 

[Jeff F]

I purchased an EGT and installed it on my Lehman diesel 120 based on recommendations from Seamoose here on Trawler forms.
The exhaust elbow on my Lehman 120 was already tapped for the EGT sensor. I just removed the plug and screwed in the EGT sensor. When running it has the raw water blowing over it mixed with the exhaust so it reads cold.

That sounds like an exhaust temperature monitoring system rather than EGT.

EGT gives temperatures before the water injection. The two measurements are completely different. EGT can reach 900F while exhaust temps are typically well under 200F.

 

[rgano]

That sounds like an exhaust temperature monitoring system rather than EGT.

EGT gives temperatures before the water injection. The two measurements are completely different. EGT can reach 900F while exhaust temps are typically well under 200F.

I have placed exhaust system alarms on all my boats' engines and generators because you may not be looking at a gauge when the raw water stops flowing as happened by my pump's output hose burst.

My EGT on my Yanmar 315 HP engine is before the turbo and runs cool at 300 degrees or less as I idle out the channel and then 1000F at 3100 RPM up on plane. 900 at 2800, still on plane. Tony Athens seem ed to think it was ok.