Lml High Egt's

rrraider · February 23, 2011

I posted this in the Diesel only section but it might be more appropriate here; or possibly get an answer.

I've had the LML for several thousand miles now and have a pretty good feel for it now and think it's going to be a good tow vehical. I do have a good bit of concern for the EGT's I am seeing in comparison to the previous LBZ which BTW was a great truck. The LML's exhaust gas tempreture is consistently 150 to 200 degrees higher at constant speed and under only moderate acceleration is 300 degrees or more higher. Example moderate acceleration (1/2 throttle or less) will produce 1050 at the 40mph point and over 1100 by the time you reach 60mph. In case the pyro is in question it is the same one off the LBZ and sensor is mounted in the same position.

Now this may all be well and good if the LML is designed to run hotter exhaust temps for emissions reasons, but in seeing the temps I have a high amount of concern for what is going to happen when we hook up the 15k fifth wheel this summer. Going over some of the tough Colorado passes with the LBZ you really had to keep the rev's up to lower the load and stay below 1450 degrees. If the LML's trend is the same in comparison when towing then the EGT would reach 1750, and I say would reach as I think pistons would have melted before then. Surely I'm not going to have to baby this truck while towing to keep it healthy. I am hoping that Exhaust temp sensor #1 is talking to the ECM and telling it to defuel and change timing at some point. Is that correct? Somethings going to have to give as I know the truck has the torque to just keep pulling until it melts if something doesn't save it or the operator doesn't have the sense to back off. What if the opperator doesn't have an EGT gauge?

Hope someone can shed some light on this.

Thanks

Randy