I just bought a 98 12V the other day. The temps here in Ohio have been in the 20s (Not THAT Cold).

Anyways, the engine temperature on my 12V "seems" to take forever to get going. The heater finally starts putting out some good heat after about 10 minutes or so.

The Coolant Temp Guage stays around 165F after sustained (10-30 miles) of Highway driving. The seems VERY low IMHO.

I know Diesels are real finniky about fuel/timing issues, but I'm guessing it "may" be in need of a new Thermostat.

Ideas ???

 

It sure sounds like the thermostat to me. I was surprised they are kinda pricy. I had to pay $31 at napa for mine.

 

You can also try the old "piece of cardboard with a hole in the middle, slid in between the inter-cooler and radiator" trick.

 

I'll do that.

At what outside temperature does one need to do the cardboard-in-front-of-the-radiator trick ??

Also, what degree thermostat should a CTD have in it ??

 

my 12 valve does the same thing as yours, runs colder in the winter, but here in fla I dont worry about it ,
if you put cardboard in front of the rad, cut a round hole in the center,you will have to play for what size to cut it at,or get a cold front kit.
hope this helps
jman

 

Just get yourself a winter front for the grill...

You can make your own out of just about anything. Aluminum, Wood, Plastic...

Really gets mine warmed up fast... 2-3 Miles and the needle is right on the 190*F mark! I would change the thermostat too to be safe... It might be a tried 180*F that is opening early. The colder block temp will cause the computer to think the truck is cold and feed more fuel too... This will decrease you MPG numbers...