Greetings fellow Z06ers. My 2008 has had an S&S top end supercharger since 22k miles. I now have 118k miles. Runs as strong as the day it was upgraded. I have had heat problems since new. At 98k miles I pulled all three radiators and water pump and pully tensioner and snake belt off and threw away the radiator and the air conditioner radiators and went new. I pulled the fan computer off the front bottom of the engine and replaced the fan wires with a switch and 10 Guage wires to the drivers side dash. I start the fan just before I start the engine . My numbers are in the 190 to 210 area including summertime and when running hard.. at 108k miles I had to replace a noisy fa that was still working. The hardest part of the job was cleaning the cold air input aluminum casting that sits in front of the radiators. I spent more money that I planned but my overheating problems are over. By the way I have a 190 Stat. Hdb
07' Z06 Overheating or am I being crazy?
I have an 07 Z06 that I got back in May of this year; it had just under 39k miles on it when I purchased it and right now it's somewhere close to 45k.
In the last month or so I've noticed that when I'm cruising the coolant temp stays between 217 and 223 depending on the speed I'm running but coming to a stop it shoots up almost instantaneously to just under 230, between 225 and 230 most of the time. I really don't recall it ever having this much fluctuation... I've always kept a pretty close eye on it and I don't recall it ever getting much over 220 or 221 up until recently.
I've checked for airflow obstructions and I've watched the thermostat cycle using a IR thermometer.
The fan comes on somewhere around 225 but it seems like it always stays on high (as I understand it these fans have an auto speed adjust).
I've seen in other forums where the temp should not exceed 220, and is usually somewhere between 212 and 217, is that under load or is that idling?
What is the standard idling temp for these things after it's warmed up? What is the standard temp with this car under load, after warm up?
Since the car is getting close to 50k, should I go ahead and get a coolant service done?
Lastly, does anyone know any good Vette mechanics in the Nashville, TN area?
I'm probably just being overprotective getting myself worked up for nothing.
Any feedback or input would be greatly appreciated.
Chuck
In the last month or so I've noticed that when I'm cruising the coolant temp stays between 217 and 223 depending on the speed I'm running but coming to a stop it shoots up almost instantaneously to just under 230, between 225 and 230 most of the time. I really don't recall it ever having this much fluctuation... I've always kept a pretty close eye on it and I don't recall it ever getting much over 220 or 221 up until recently.
I've checked for airflow obstructions and I've watched the thermostat cycle using a IR thermometer.
The fan comes on somewhere around 225 but it seems like it always stays on high (as I understand it these fans have an auto speed adjust).
I've seen in other forums where the temp should not exceed 220, and is usually somewhere between 212 and 217, is that under load or is that idling?
What is the standard idling temp for these things after it's warmed up? What is the standard temp with this car under load, after warm up?
Since the car is getting close to 50k, should I go ahead and get a coolant service done?
Lastly, does anyone know any good Vette mechanics in the Nashville, TN area?
I'm probably just being overprotective getting myself worked up for nothing.
Any feedback or input would be greatly appreciated.
Chuck
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FYI, you say in the title of your post that you have a 2007 but then state in content that it is a 2008
Being the LS7 is a small block punched out to a 427 CU would run hotter and being an aluminum block does not transmit heat out as well as a steel block
Add heating up the air with the supercharger, the total of design raises heat temperatures
I would not have gone the route you did with that switch
The PCM decides how it controls in many cases as what the coolant temp is
It also does SMOG and other tests depending on the coolant temps during warm up from a cold start
IF you're forcing the fan ON 100% rotation on cold start also then means it will take longer for the coolant temps to heat up enough so that PCM will go into closed loop mode
This means you're forcing the engine to be run in open loop longer and PCM dos not fully control fuel and timing while in that mode
The stock GM PCM calibration is what controls when fan(s) are commanded on as to what the coolant temp is and then commands how much rotation the fan will be commanded to turn
Here is the stock setting for example the PCM does not command fan rotation (only 15 %) when coolant reported is 93 C (199 F) degrees
And as you see, does not command fan rotation to 100% until coolant is really hot
Being you have a supercharger also means the PCM would have to be tuned for that
What should be done is change the values in this fan table to command fan on sooner and with higher rotations sooner than it is now
Total heat also can be what type of engine oil used, the weight used, and if using a good engine oil cooler
Then to reduce heat which kills off performance (hot charge to cylinders) is to install a water/Methanol kit
which will reduce cylinder volume temps 40 plus degrees
Elevation, weather and type of gas used will add to overall engine temps
Lastly, assure hood as now is venting hot air out of engine bay will greatly help over all temp as to engine and exhaust system design
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Being the LS7 is a small block punched out to a 427 CU would run hotter and being an aluminum block does not transmit heat out as well as a steel block
Add heating up the air with the supercharger, the total of design raises heat temperatures
I would not have gone the route you did with that switch
The PCM decides how it controls in many cases as what the coolant temp is
It also does SMOG and other tests depending on the coolant temps during warm up from a cold start
IF you're forcing the fan ON 100% rotation on cold start also then means it will take longer for the coolant temps to heat up enough so that PCM will go into closed loop mode
This means you're forcing the engine to be run in open loop longer and PCM dos not fully control fuel and timing while in that mode
The stock GM PCM calibration is what controls when fan(s) are commanded on as to what the coolant temp is and then commands how much rotation the fan will be commanded to turn
Here is the stock setting for example the PCM does not command fan rotation (only 15 %) when coolant reported is 93 C (199 F) degrees
And as you see, does not command fan rotation to 100% until coolant is really hot
Being you have a supercharger also means the PCM would have to be tuned for that
What should be done is change the values in this fan table to command fan on sooner and with higher rotations sooner than it is now
Total heat also can be what type of engine oil used, the weight used, and if using a good engine oil cooler
Then to reduce heat which kills off performance (hot charge to cylinders) is to install a water/Methanol kit
which will reduce cylinder volume temps 40 plus degrees
Elevation, weather and type of gas used will add to overall engine temps
Lastly, assure hood as now is venting hot air out of engine bay will greatly help over all temp as to engine and exhaust system design
Thank you for the accurate detailed and helpful information!
That is what makes a Forum like this work !
Jonathan
Thank you for the detailed, accurate, and helpful information! That's what makes a Forum like this work. It's much appreciated!
PS: side hood vents were covered due to outside temps and vents keeping this 09 Z06 too cool!
Jonathan
21 - 24 of 24 Posts
