I have a 1999 c5 corvette with 157,000 Miles I noticed it was getting warmer then I thought it should, I replace water pump, radiator and 182 stock T-stat and filled with Dexcool antifreeze, and it seems to still get to 225 plus degrees, I read that the second fan doesn't come on until 225, is this normal or do I need to bleed the cooling system some how? What should be normal operating temps be? Thanks.

 

Prestone Dex-Cool Extended Life Antifreeze/Coolant,

COOLING SYSTEM BLEEDING
1. Fill system through radiator surge tank opening up to base of fill neck. Start engine and idle
for one minute. Install radiator surge tank cap. Cycle RPM from idle to 3000 in 30 second
intervals until engine coolant reaches 210°F (99°C). Shut off engine.
2. Loosen radiator surge tank cap. After all hissing stops, remove cap. Start engine. Idle engine
for one minute and fill surge tank to between FULL COLD and FULL HOT. Install radiator
surge tank cap. Cycle RPM from idle to 3000 in 30 second intervals until engine coolant
reaches 210°F (99°C). Shut off engine. Top off coolant as necessary.

Is the condenser clean ???

 

Yes condenser is clean.

 

I don't know if this helps you, I have a mail order tune from ECS. I installed a 180 stat and the tune has the fans come on earlier, I think 195 and 205 ??? it runs 95% of the time at 192 !!!

 

I have the same thing with a 160 stat. My temps are about ten degrees cooler 185-195.

 

Your temps are the aprox. of mine also...with a 160 t-stat.

 

Ok so I installed a new 160 degree thermostat and I'm still having the same problem, any other suggestions?

 

What are the conditions under which it gets to 225 degrees?

Idle, around town?

A/C on?

Fast freeway driving?

There could still be air in the heads. There are a number of posts on burping the heads or getting air out of the heads.

Make sure that the coolant air bleed pipe and relief ports and hose from the heads are in fact clear, including the ports in the heads. These ports in the heads are small and could become plugged if the coolant has not been changed on schedule.

 

see post #2

 

that's why I rerouted my steam lines, don't have to bleed !!

 

If the ports in the heads are clear, the method from the FSM in post #2 should get the air out, but some people still experience overheating after that procedure.

If post #2 doesn't solve the problem, you can first get a 3' length of 1/4" hose from the auto parts store and a 1/4"- 1/4" barb- barb brass connector and hose clamps, cut the air bleed hose in a convenient spot before it goes into the radiator. Bend over and tape wrap the air bleed hose coming from the radiator so it does not leak. Extend the air bleed hose coming from the throttle body to a container on the floor along side the right front fender (in standard configuration the air bleed pipe is connected to the throttle body, then comes from the throttle body to the radiator).

Run the engine long enough that coolant flowing into the container on the floor does not have bubbles in it. In my experience, as much as two quarts will come out before the bubbles stop.

If coolant comes out and bubbles stop, then reconnect the air bleed hose with the brass barb- barb connector and clamps, top off coolant in the surge tank.

If coolant does not come out, the air bleed ports in the heads or the air bleed pipe, throttle body or hose may be clogged and require disassembly and cleaning.

You can also take this opportunity to bypass the throttle body, and route the air bleed hose directly to the radiator as many have done.

Keep an eye on the coolant level in the surge tank while using the above bleed method, you may have to shut down briefly to add coolant.

 

Actually 226 is not "OVERHEATING" I'm surprised noone has said this but that is the way the car is supposed to be from the factory....


"The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).

This is right from the tech manual.

 

I knew you would be chiming in.

 

I was a bit concerned about the high temps on my 2002 although as stated it's pretty much common for the LS1, so instead of any major change I just installed one of these and just press a button to lower the temp whenever I need to. Works great & easy to install(have the wireless unit).

http://www.saccitycorvette.com/HardWireCoolit.html