Help for customer with engine troubles

Customer Problem

I have a question I hope you can help me out with. I have a driver who is in a peterbuilt 387, the mileage is roughly about 485,000 miles. The driver is telling me while he was driving the truck; the truck shut off for about 1 or 2 seconds then turn right back on. Prior to this, the truck was running a at a normal temp of 180-190. The truck is now running at 200--210 temp. The driver now feels he has lost some pulling power and feels it is driving a different than what it was before. Can you tell me what I might look for or need to do to try to diagnose this problem? I hope I have provided you with enough information. If not please let me know.


Gary's Reply

The normal temp on the cat is 200 to 205, any lower and it affects the fuel mileage . There should be a code recorded in the ECM for the momentary cut out . Tell him if it does it again to see if all the gages fall back to zero at the same time. Also if he toggles the cruise control switch back and forth when it happens it will take a snapshot of the event.
Let me know if this helps .
Gary