simpleFoam temperature blows up
 

I've been using a modified simpleFoam solver to include temperature which compiles correctly and is running smoothly however the temperature explodes after the first timestep. Despite the crazy values for T, the U and p results seem to be correct.

I noticed a lot of iterations were required for T and p, so I tweaked the FVsolution file as per this post:
http://www.cfd-online.com/Forums/ope...terations.html

are there any other tricks that I might try to get this model to behave?