I have heard that GM made changes to address cooling issues starting with the '17 Z06. Were the '17s produced with this cooling upgrade already installed, or did it start with the '18 cars?

Thanks!

 

17's Factory Installed

 

what were the changes??

 

2017 Z06 Changes and Improvements

 

Supercharger intercooler bricks were changed to increase charge cooling to the two rear cylinders. That required a higher supercharger cover which drove a different hood liner so the combo could fit under a closed hood. The 2017 and newer intercooler bricks are tapered thus thicker in the rear than they are in the front. The thicker portion provides more charge cooling for cylinders number 7 and 8 which have higher combustion temperatures than the other 6 cylinders.

M7s also got the GMPP Secondary Radiator that was a GMPP part included as standard equipment. This part can be added to 15 and 16 M7s for less than $1K.

Bill

 

They only added the 2nd rad on the manual trans car. The 17 auto cars still over heat on track.

 

Correct because that radiator/heat exchanger is used to cool transmission fluid on the A8 Z06’s.

 

the 17 still has the overheating problem. mine has gone into limp mode just running it a little aggressively on the highway. Since I had a 15 with the problem I asked them specifically and was told it was corrected. It wasn't. Really one pissed off person right now. Don't buy the automatic and if you plan to track the car, and if you go manual get LG's cooling kit.

 

 

 

Their target was for a professional level driver to be able to drive on track in 86 F ambient temperatures, which apparently was the same target used for previous generation Corvettes. This was increased to 100F for the ZR1 and I believe also all 2017 and newer Corvettes.

 

 

When does the ZO6 start pulling timing? 194 degrees? Is that coolant temperature or engine oil temperature? My car seems to mostly always be running hotter than that here in Albuquerque New Mexico where it's hot

 

Well, maybe more than a little. It was a back road that turns into a four lane divided highway (in Mexico) that stretched for a few miles. Temps were mid to upper 80's. I short shifted the A8 hoping to avoid overheating the trans. I hit 170 and it went into limp mode and stayed there until I turned the car off for a while.

 

Thanks for the feedback. I don't think that is the problem but I will take it in so I can begin the lemon law process. Doubt that it will be successful but I have to try. I think the strategy of Class Action against GM is doomed. I think people should pursue a claim against the dealer. I intend to do that.

 

170. NICE.

 

RFgoss,

What was the outside air temperature? Was it still pulling hard at 170? I've only got mine to 150, everything was cool i just backed off. What speed do the automatics kind of level off? You know when they just kind of stop pulling. I have stage 2. Also, I would think straight line wouldn't overheat because all the air going through the car at speed. Thanks.

 

Ambient was between 85-88. It was still pulling but not as hard. I had been going through some twisties prior to the straight line.

 

We make a variation for the auto trans cars. Give me a call 972-429-1963.

Thanks

Dane

 

Check your intercooler reservoir fill. If it has the air gap at the top that most have when delivered it needs to be bled. As of March 2018 there is a TSB that covers this. It is related to random misfires with code P0300 being set. That code may not set a check engine light so you have to scan for it after something happens. The air gap at the top of the reservoir needs to be no larger than the size of two quarters and it takes a couple of hours of vacuum bleeding to get it down to that size. Here is what mine looked like before spending time at the dealership getting it bled.


After using the ZR1 Bleed Tool (shown in picture below) and lifting the front of the car two ft off the ground to help get air out of the reservoir this is what it looked like:




After this was done I went to the NCM VIR HPDE on 6-25-18. I ran three sessions on Monday. The first session the ambient temp was in the mid 70s and the car ran great with no misfires or drop off in power. Total time on track was approximately 20 minutes. During the second session which was about 1:30 in the afternoon I had one lap where I felt a little misfire going up the back straight. The ambient temp then was right around 87 degrees and total time on track was about 15 minutes. During the final run at 5:00 PM I didn't feel any misfires and I set my best lap time ever at 2:03:11. The ambient temp then was 86 degrees, total time on track was about 15 minutes. I believe the bleeding helped considerably. I wasn't getting anywhere near the drop off in top speed that I would get in any of those temperature ranges before the vacuum bleeding. When I noticed the large power drop top speed at the top of the hill on the back straight at VIR would drop 10 to 13 mph (from 150 down to 137 to 140). This time I was seeing a 4 or 5 mph drop off with warmer temps but I would see that on my C6Z as well as temps climbed over a day's time. I am not sure what caused the misfire feeling during the second session but it was only on one lap and there weren't any codes set.

You have to get the air out of the intercooler and that means out of the reservoir, any air traps inside the system you can't see and the coolant has to be up inside the pipe where the fill cap is located. Any air in the horizontal lines below the fill cap will kill you even if the reservoir looks OK.

Am I sure this is the resolution to my two year misfire saga? No. However, it is a good start.

Here is the TSB Info: 18-NA-088: Reduced Performance or Malfunction Indicator Lamp Illuminated with DTC P0300 (Engine Misfire Detected) Set After Service or Replacement of the Charge Air Cooler - (Mar 19, 2018) Subject:
Reduced Performance or Malfunction Indicator Lamp Illuminated with DTC P0300 (Engine Misfire Detected) Set After Service or Replacement of the Charge Air Cooler
Some customers may comment on reduced performance or an engine misfire during high ambient temperatures during track driving conditions. During diagnosis, a technician may find DTC P0300 (Engine Misfire Detected) set or stored in the Engine Control Module (ECM).This may be due to the supercharger’s air charge cooler system not being properly evacuated and filled after service or replacement.See the proper procedure below for correction.

I would also like to comment about the A8 and how it operates on track. I had a novice student with a C7 GS with the A8 and this is the first time I have actually experienced A8 operation. When set in Track Sport 1 that trans stayed in lower gears buzzing the engine when it didn't need to. When the student was driving up the bridge straight at a constant speed between 75 and 80 the tach showed the engine rpms at 4200. I talked to several other instructors about how I could get it set so the student could drive in just 4th or 5th gear and not have the transmission constantly downshifting with the slightest press of the throttle. It wasn't very conducive to teaching throttle control. The advantage of working with any C5/C6/C7 Manual Transmission Corvette is you can have the student put it in 4th gear and leave it there because there is so much engine torque throughout the rpm range. That makes it a lot easier to teach throttle control rather than touching the throttle having the transmission downshift and the student then reacting by lifting. After a while we put the Drive Mode in Sport and that let the engine run at more normal rpms but didn't stop the constant needless shifting. I can see how that would drive an A8 Z06 into an over heating situation since higher rpms generate more heat whether or not more power is being produced. I think if you are driving an A8 Z06 you can't be timid with it. To run any long duration on track you need to be on top of your game and operating at a high speed. That way you have the speed required to get cooling air through the radiator. Half hearted running will more than likely cause the car to over heat rapidly. Too many rpms at too low of a speed.

Bill