Hello,

drove my 03 today on the hwy for about 1hr 15 minutes with the weather being 92 degrees. Typically runs around 185-195 but was at 220 average today and got up to 230. Is this normal?

 

220 isn't unusual when ambient temps get into the mid to upper 90's. We hit 102 here in Georgia and i was at 220

 

Do you have the stock front bumper and all 3 parts of the air dam in place?

 

Those temps are COMPLETELY normal! No problem what-so-ever!

 

Moved to C5 Tech for further discussion.

 

It's been a hot one lately. I'm in Arkansas reaching high 90's daily. I installed a zr1 style lip l, and I was able to keep my air dam on(yes all 3 pieces) Doesn't matter through my car is running hot. Yesterday I was 226° across the board. Oil, coolant, trans. Letting her run on the highway only dropped temps initially. I'm going to take the splitter off today, and see if I can cut some low vials slots in the front of the splitter under the radiator to restore air flow. If not I'll just keep the piece off until it cools down here. It's a quick job. Glad I didn't use the 3m tape that stuff is always messy.

 

Looks like you found the most likely cause for higher coolant temperatures; your splitter. This seems to a very common theme with many of the coolant temperature threads.

A bone stock car like my ‘99 MT remains under thermostat control (192 to 196 degrees) on highway driving in 6th gear at 101 degree ambient.

 

I had to replace one fan motor and the cube relays that run the fans independently on my 2002 C5. It started cooling back to normal after I did that work. Last summer I noticed the temperature walking around up to 230 in stop and go traffic (I know, normal) so a few weeks back I had it up on a lift and took a bright light under between the radiator and the diff cooler (z51 package). To my amazement, it looked like there was a bail of hay in between the two. I remembered that where I used to work at the grass cutting people would blow all the clippings off the parking lot and under all the cars, I could tell because every week I had to clean the cowl of clippings and leafs. Now I know where all the grass they cut went. I bought a clothes dryer lint brush from HD and started passing it between the radiator and cooler, imagine my disbelief when a tray full off dead grass came off the fins. I did this for two hours and just when I thought I had it all out, I would sweep the brush up and more dead grass would fall out. Now my car stays at temps below 220 as it did when it was new from factory. I sure wish I would have taken pictures for show and tell...

 

Sounds a little hot, but not terrible.
Aside from the air dam question previously addressed, maybe the radiator needs external cleaning. I had to do that.

 

1. careful with where coolant scalar is measured, 226*F water going INto the engine would worry me but 227*F coming OUT of the engine is ideal, very economical with oil temp of 220*F

2. Oil is the true coolant, and more important to measure when things are getting uncomfortably warm for an engine. Keep the oil temps near the boiling point of water 210-220*F because of the influence temp has on viscosity and behavior of oil, is prio. Focus not just on the water as oil coolant is critical for keeping engine alive and healthy. Oil cooling will help keep coolant water cool in the engine and the oil behavior in check.

3. The temperature 'gauge' accuracy is always a second guess. If you see 226*F for example is that really 228 or 230? Remember it is a scalar measurement. Usually a range is acceptable - like 'idiot' gauge, how hot is red? We don't know and its fine. However as you venture into unknown and performance territory the further you go the more important it becomes to know exactly how hot and where how hot. I am not saying you need to do this but ideally to make these "is it too hot really" observations you need a combination of all 1, 2, 3 here and 3 particular is attach a high accuracy mechanical gauge to a point of interest in the cooling coolant oil/water/transmission and really get to know the vehicle behaviors and make more accurate observations.