Since it was raining too hard yesterday and last night to go out and fool with the truck, I spent lots of time with my shop manual, plus the Internet, especially the DieselStopforum and the GaleBanks website. The DieselStop is an AWESOME site. I just did a lot of searching and gained enough information to be able to look at some possibilities today.
So here's the order I checked;
1. Blown head gasket
: Don't think so, but there is some oil leakage at the join that I have to check out further.
2. Dirty radiator exterior, both front and back: Nope. Looks pretty good.
3. Obstruction in the turbo intake: Didn't see anything, but that doesn't mean there isn't something. When I opened the hood, a chipmunk popped out of the nest it had built on top of the engine and looked at me with great irritation before skedaddling. I spent half an hour or so pulling the nest out of there, but still have to get some high pressure air to it to blow out the rest.
4. Dirty coolant (meaning dirty or clogged radiator): Nope, nice and green.
5. Dirty oil: Possibility. I do need to change it. It has been about 3k since the last change.
6. Dirty filter: Haven't checked that yet. Will do so when I change the oil.
7. Faulty gauge: Real possibility. When I went to start the engine to visually check for active oil leaks at the rocker cover mentioned above, I glanced at the EGT gauge and noticed that COLD it was registering about 200. Since the truck had been sitting a couple of days, I knew that couldn't be right. Oh well, I've been thinking of installing a complete set of gauges and maybe now is the time. The EGT is the only one I have and it is a no-name. Any recommendations? I'm leaning toward ISSIPRO (?).
BTW, from the DieselStop forum I learned about pre and post-turbo temp probes. I couldn't figure out which mine had. This is an aftermarket Banks Sidewinder set up. Iím not sure if it was installed completely correctly since I donít seem to have the power boost that the DieselStop guys and the Banks website imply will happen.
In answer to FlyingCloudís questions:
1.How long have you had your gages on your tow vehicle?
It was in it when I bought the truck (as a complete newbie to diesel) used in í97.
2.I assume that you're not towing "full-time"? Aside from the IDL temp range, what is your average trip indication around town and/or on extended trips while not under tow?
It used to stay pretty much at the bottom of the gauge, maybe moving up to 250. Towing on the interstate might see 350.
3.Just for my own references, what kind of gages are you using besides EGT? make/analog/digital??
Only an EGT, no-name analog.
4. What are the other gages reading and, have any of those peaked sharply as well?
The instrument cluster is the standard +/- gauges, so there arenít really good indicators, but nothing in the cluster has acted strangely.
5.Did this happen while under other than normal situation? Like climbing a very steep grade for extended period?
No, just seems to be running hotter. Also, there is a lot of heat coming into the cab on the right side, even with the heater off. This is the same side as the oil leak mentioned above.
6. When was the last time you had the vehicle in for services for air filter change, oil/oil filter/tranny/fuel filter replacement??
About 3-4k ago. (I know. I know. "about" isnít very good! Sort of like the +/- gauges!!
Well, that's it for now. I'll report more when I have talked to some technicians. Thanks for the help thus far.