Narrative:

After departing 3DW at XA00 on a VFR flight following; an indicator came on in the cockpit indicating a 500+ degree cylinder temperature for cylinder #1. I advised sgf approach for a request to deviate to lebanon; mo. The cylinder became hotter and I immediately landed at 1MO (mountain grove). Due to the distance from sgf and my desire to effectuate a precautionary landing; I was unable to relay my communication to sgf and cancel flight following. At 1MO; there was no cell phone reception and I did not call FSS from a landline and a search was initiated by sgf. Sgf eventually called 1MO and I confirmed we were safe.

Google
 

Original NASA ASRS Text

Title: A C172 PLT ON A VFR FLT PLAN EXPERIENCED HIGH CYLINDER HEAD TEMP AND DIVERTED TO AN UNCTLED ARPT. HE WAS UNABLE TO CONTACT ATC AND A SEARCH WAS INITIATED.

Narrative: AFTER DEPARTING 3DW AT XA00 ON A VFR FLT FOLLOWING; AN INDICATOR CAME ON IN THE COCKPIT INDICATING A 500+ DEG CYLINDER TEMP FOR CYLINDER #1. I ADVISED SGF APCH FOR A REQUEST TO DEVIATE TO LEBANON; MO. THE CYLINDER BECAME HOTTER AND I IMMEDIATELY LANDED AT 1MO (MOUNTAIN GROVE). DUE TO THE DISTANCE FROM SGF AND MY DESIRE TO EFFECTUATE A PRECAUTIONARY LNDG; I WAS UNABLE TO RELAY MY COM TO SGF AND CANCEL FLT FOLLOWING. AT 1MO; THERE WAS NO CELL PHONE RECEPTION AND I DID NOT CALL FSS FROM A LANDLINE AND A SEARCH WAS INITIATED BY SGF. SGF EVENTUALLY CALLED 1MO AND I CONFIRMED WE WERE SAFE.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.