First trip towing:

EGT runs 300 degrees at idle

Easy to maintain under 1200 degrees towing 12,000 lbs. thru the <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><st1:place w:st="on">Rocky Mountains</st1:place> at 55 to 65 mph.

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Third trip towing:

EGT shows ZERO degrees at idle

Previous experiences indicate that pyro is reading 300 degrees lower than usual throughout the range.

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Prior to next trip, replace the EGT gauge and thermocouple…temps read 300 at idle again.

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This latest trip:

Installed winter front due to cold weather. Hit the road on I-70. First grade west of city causes EGT to hit 1250 degrees…unable to maintain more than 45 mph without excessive temp. Coolant and trans temps remain normal.

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Next morning with warmer temps expected…removed winter front. EGT returns to normal temps…able to climb hills at 55 to 65 mph without excessive EGT.

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Why would the winter front cause higher EGT readings?

Intercooler is not getting cold air.:lol:

GM also states we are not supposed to tow with the grill cover on because of this very reason. Makes me appreciate the intercooler that much more knowing the amount of heat it takes out...

4x4man is right. My owner's manual states that the winter covers should not be used when towing, as full air flow is needed.

Thanks for the replies. I guess I missed that part in the manual. At least we now know that the recommendation is accurate.