well I went the cheap route and bought a pack of BB's.... We'll see I guess.

 

most people with fi do the stat mod. my truck holds steady at 178-180 with the 160stat.

 

My 160* is the same - runs 175* to 180* . It may heat up a little more when sitting in hot temps or when doing WOT runs.

A 160* stat begins to open at 160* and should be fully open at 175* which seems to be what people are seeing. Ran mine all winter with no problems and had lots of heat inside the cab.

 

Ive said this before and I will say it again. I really do not understand this mod much. I have a stock tstat and my temp stays pretty consistent @ 185* even in 110+weather in the central valley. What is 10-20 degrees really going to do?

 

How are you measuring your ECTs? If you are using the instrument cluster gauge it may not be accurate.

The stock thermostat in my truck says it is a 86/100*C or that it opens at 86*C and is fully open at 100*C and my cluster gauge always read just under 100*C. It now reads just over 75*C.

75*C = 167*F
86*C = 187*F
100*C = 212*F

Logging software says my engine ECT is between 175*F and 180*F under normal operating conditions with the 160* stat. I never logged the stock stat but I think I am running 30*F to 35*F cooler with the 160*F stat. That in turn means that my engine is running that much cooler and less prone to detonation and that means I should be able to run a little more timing and/or boost or maintain a larger safety margin.

 

logging with HPtuners...says 185* ect most of the time...very rarely goes over that...just kinda warms up to that and stays at that...if ive been driving a lot on a hot day it might say 190*

 

Well that does not sound like stock operating temperatures to me but I am not exactly sure what a 99 should run. It sounds like your temperature sender is reading low or you stat has been changed out for a 170* at some point in time. One way or another your operating temps appear to be 20*F to 25*F below stock already so no worries enjoy.

 

definitely not stock...
also...these temp reducing additives...varying in price from probably $7-$25ea...have tried the RP and the new "Q"...must only work with water only applications or at most a 15% mix...I have seen absolutely no reduction in temp.

 

well it must have been done when I bought it then because I havent swapped it. I thought it was completely stock when I got it except for exhaust but I guess not.

 

mine use to run 220 or better. overheated al the time too. so i went to a 160 and the bigger 34" core radiator and 05 efans. now its 175-180 all the time