What is the Max. allowable running temp for the L98? 235 makes me uncomfortable. I usually shut off my A/C when it gets up that high.

 

The owners manual says to shut off the engine when the coolant temperature reaches 260 F. 235 won't hurt your engine, but there are a number of things you can do to lower your operating temperature. Summer temps and the a/c on while sitting at a light or under 35 mph reduces the air flow through the radiator and reduces the water pump flow rate. This lowers the rate of heat transfer from the radiator to the atmosphere and makes your coolant temperature rise. First, make sure you do not have debris between the radiator and the a/c condenser, this cuts airflow. C4's collect debris off the road and need to be periodically cleaned out. Check and straighten radiator fins. I installed a Stewart water pump which has a higher flow rate and it made a lot of difference compared to the factory water pump. Some help from turning on the fan at a lower temperature will help, but the fan is already on when the a/c is on so this may not help in your case. Lower the percent antifreeze in the summer and/or use one of the coolant additives like Red Line. Install a larger heat capacity radiator.
C4's don't boil over at 235 F, and their design includes higher operating temperatures and it takes some getting used to when past vehicles we have owned boiled over at these temperatures.
Note that I did not recommend installing a lower temperature thermostat. A lower temperature stat will not reduce coolant temps under 35 mph in the summer and is a waste of effort. Temperature is controlled by the ability of the radiator to get rid of heat, the thermostat merely controls the coolant temperature IF the radiator can remove heat fast enough.

 

Thanks for the in-depth reply. I actually had pulled the radiator and cleaned it and the area between the condensor and the radiator. My fans are wired alway on. The previous owner did it.

 

In AZ, i would definitely install a 160 Thermostat. The car will take longer to warm up, and as such it wont reach these hot temps so fast and maybe not at all if you dont drive it that long each trip.

My car runs cooler with the 160, with my fan reprogram, the engine almost never sees temps over 200F (coolant), and even then on the hottest and most humid days in heavy traffic and extended driving. It ran cooler before the reprogram as well.

I would not allow any engine to get higher than 245F coolant, unless it was during a road racing event. The oil, if its Mobil 1, is good up to 300 or so. Dino oil breaks down above 250, but for racing it would hold together fine (but need an oil change immediately afterwards)

 

Not much we can do, living here in the desert. Even with a 160 thermostat and reprograming the fans, my '93 will still get up in the 130's in traffic. I try not to drive in town when the outside temp. exceeds 107 degrees. It still beats having to park it all winter because of the snow!

 

Oops, I meant the 230's.