Going thru the exact same issue same issue......Have your system checked while light is still on. Dealer is Austin did it while I waited. Delta was 22 degrees......restricted oil cooler. ERG cooler tested fine, but doesn't matter cuz it still needs replacing/deleting. Drove back home 60 miles....light came back on. Check under truck this morning and appears degas bottle burped, due to flashpoint, and spewed about a pint onto the driveway. This is the very first loss of coolant for me. From everything I have learned here.....it appears that my EGR cooler has/or is about ready to rupture. In either case oill cooler needs to be replaced AND ERG needs to be replace/deleted.
Tried the "glove" test to check head gaskets.....no inflation. So it appears that my oil cooler bcame restricted, wrench light would come on under cruising temps, I luckily swung by a dealer to have it checked, had my first Degas "burp", and it "Appears" that the head gaskets are still intact.
As a result.....I'm flushing the gold crap out (replacing with silicate free coolant), replacing oil cooler and ERG (BPD's, no delete), Cleaning/repalcing EGR valve as needed, adding a fuel pressure reg upgrade spring, installing Sinister"s coolant filter, and NOT touching the headbolts, yet (too pricey). and lastly....adding a scan tool to monitor all system temps, especially ECT/EOT. NOT BAD for a newbie with internet and a diesel forum....LOL
Work done at dealer...3-3.5K.....My driveway, with help from my firends here. 1-1.2K. blow your heads....dealer will charge upwards of 5K. Huge savings to be had with early detection.
MY SUGGESTION!!!!!! spend lots of time reading....excellent info here. Bullet Proof Diesel has some excellent videos explaining how everything is interrelated, made sense to this diesel newbie.
***Most importantly*** check your ECT/EOT differential!!! ASAP...before all else goes south......then the costs can really rack up!!!!!
Hope this helped.....
PJ