[Z OH 6]

Originally Posted by mlee

Yes, we saw this happen in 2017 at NCM with the regular ZL1

So, only the M6's are reliable at the track under extreme conditions?

[mlee]

Originally Posted by Z OH 6

So, only the M6's are reliable at the track under extreme conditions?

Seems that way... also extreme conditions or really good driver is the key. I saw it in July with a pro driver in the seat. With the car's owner no issue.

[clg82]

Following along as this is an interesting read. Plan on doing plenty of track days here in Texas this summer and will want to keep an eye on this. Would having your TCM tuned help alleviate this issue?

[Z OH 6]

Originally Posted by mlee

Seems that way... also extreme conditions or really good driver is the key. I saw it in July with a pro driver in the seat. With the car's owner no issue.

Interesting, I will never see this issue. Just curious

[mlee]

Originally Posted by Z OH 6

Interesting, I will never see this issue. Just curious

My M6 ZLE will see all the track time and even if I did track the A10 Panther I doubt I would see it either.

Possibly what the OP mentioned about overfill had something to do with it. I've never seen a definitive cause yet.

[Slurpee]

Originally Posted by mlee

My M6 ZLE will see all the track time and even if I did track the A10 Panther I doubt I would see it either.

Possibly what the OP mentioned about overfill had something to do with it. I've never seen a definitive cause yet.

I don't think GM knows either. My dealer opened a technical case with GM about it, and since then they have not returned my calls.

[Badmojo]

It is transmission fluid level related. It has nothing to do with oil temperature. You can set the fluid level by coming off track hot and then immediately jacking the car up in the pits. Have a friend to speed things up. Do not get under the car without jack stands and gloves. Have a drain pan and remove the single bolt on the bottom of the pan with the car running. Anticipate a few ounces to a quart of fluid to come out.


If this doesn't fix the problem:


1. Ensure that the top and bottom coolant reservoirs are properly filled. Burp the cooling system.
2. Check if the transmission cooler is plugged with rocks or debris.
3. Replace the factory thermostat with a factory replacement or Katech 174 deg. (I had a factory t-stat fail)

[SpeZ]

Originally Posted by Badmojo

1. Ensure that the top and bottom coolant reservoirs are properly filled. Burp the cooling system.
2. Check if the transmission cooler is plugged with rocks or debris.
3. Replace the factory thermostat with a factory replacement or Katech 174 deg. (I had a factory t-stat fail)

Coolant resevoirs are not transmission related.
The transmission got its own cooling with a single radiator. Its the one laying horizontal and I believe it does not have a thermostat. No clue if it can get vented tho nor if it's seperated of the fluid in the pan.

[mlee]

Originally Posted by Slurpee

I don't think GM knows either. My dealer opened a technical case with GM about it, and since then they have not returned my calls.

It just seems to be hitting a limit where heat is concerned. It does suck for anyone that can hit those limits.

[Badmojo]

Originally Posted by SpeZ

Coolant resevoirs are not transmission related.
The transmission got its own cooling with a single radiator. Its the one laying horizontal and I believe it does not have a thermostat. No clue if it can get vented tho nor if it's seperated of the fluid in the pan.

Read the first part of my post.


Sent from my iPhone using Tapatalk Pro

[radz28]

Originally Posted by SpeZ

Coolant resevoirs are not transmission related.
The transmission got its own cooling with a single radiator. Its the one laying horizontal and I believe it does not have a thermostat. No clue if it can get vented tho nor if it's seperated of the fluid in the pan.

I believe the tranny fluid (which is also the rear differential fluid coolant) also goes through the engine coolant radiator (as does the engine oil for the engine oil cooler). It seems to me the engine coolant temperature goes up, and starts saturating the engine and tranny oil coolers (in opposite radiator end tanks of the primary engine coolant radiator), then pushing those respective fluid temperatures higher, and gets to the point all of those heat exchangers are out of heat rejection capacity. Then - all of those temperatures go out of control.

I am not the one that seemed to have solved this. Member TravisLambert seemed to have solved this by substituting the auxillary blower heat exchanger with a dedicated engine oil cooler (C&R, I think). He left the OEM engine oil cooler (off the side of the oil pan) in-line (and think he was going to divorce it completely later and see if there was further improvement in temperatures), and did have upgraded blower/engine/auxillary engine heat exchangers (which his data showed almost no improvement) but after removing the engine oil load, all temperatures in that cooling circuit dropped considerably, and he observed no ill side effects of track use. He's got a big thread on it. I think he was mod'd with a 2650, and is an M6, so it's a little different, but might be useful. I didn't notice mod's but that could play a factor, too, if so.

OP: I hope you find the solution

[Slurpee]

Originally Posted by Badmojo

It is transmission fluid level related. It has nothing to do with oil temperature. You can set the fluid level by coming off track hot and then immediately jacking the car up in the pits. Have a friend to speed things up. Do not get under the car without jack stands and gloves. Have a drain pan and remove the single bolt on the bottom of the pan with the car running. Anticipate a few ounces to a quart of fluid to come out.


If this doesn't fix the problem:


1. Ensure that the top and bottom coolant reservoirs are properly filled. Burp the cooling system.
2. Check if the transmission cooler is plugged with rocks or debris.
3. Replace the factory thermostat with a factory replacement or Katech 174 deg. (I had a factory t-stat fail)

The only problem with this is you may be in an underfill condition if you are performing the level check at track temps (225+). If your trans blows and you are underfilled, I bet GM would deny the warranty. The 2017 manual states to check the level at 212F. At some point between 2017-2020, it was changed to 173F for at least 2020+ (the dealer showed me the dealer service manual, which conflicts the 2017 service manual that is floating around in the forums).

[Rapid_blue_zl1_22]

Originally Posted by radz28

I believe the tranny fluid (which is also the rear differential fluid coolant) also goes through the engine coolant radiator (as does the engine oil for the engine oil cooler). It seems to me the engine coolant temperature goes up, and starts saturating the engine and tranny oil coolers (in opposite radiator end tanks of the primary engine coolant radiator), then pushing those respective fluid temperatures higher, and gets to the point all of those heat exchangers are out of heat rejection capacity. Then - all of those temperatures go out of control.

I am not the one that seemed to have solved this. Member TravisLambert seemed to have solved this by substituting the auxillary blower heat exchanger with a dedicated engine oil cooler (C&R, I think). He left the OEM engine oil cooler (off the side of the oil pan) in-line (and think he was going to divorce it completely later and see if there was further improvement in temperatures), and did have upgraded blower/engine/auxillary engine heat exchangers (which his data showed almost no improvement) but after removing the engine oil load, all temperatures in that cooling circuit dropped considerably, and he observed no ill side effects of track use. He's got a big thread on it. I think he was mod'd with a 2650, and is an M6, so it's a little different, but might be useful. I didn't notice mod's but that could play a factor, too, if so.

OP: I hope you find the solution

I did something similar, but worked extremely well. Instead of replacing the aux supercharger heat exchanger, I replaced the aux radiator with the C&R oil cooler. I did however, remove the factory oil "cooler" (heater). After doing this, I actually saw lower engine coolant temperature and lower oil temperature on track. Deleting the OEM oil cooler reduced coolant temperature so much that the secondary radiator is no longer needed. Plus, you still get to keep the aux supercharger HX, which is very much needed.

[radz28]

Originally Posted by Rapid_blue_zl1_22

I did something similar, but worked extremely well. Instead of replacing the aux supercharger heat exchanger, I replaced the aux radiator with the C&R oil cooler. I did however, remove the factory oil "cooler" (heater). After doing this, I actually saw lower engine coolant temperature and lower oil temperature on track. Deleting the OEM oil cooler reduced coolant temperature so much that the secondary radiator is no longer needed. Plus, you still get to keep the aux supercharger HX, which is very much needed.

I think I remembered your thread! I think it was the newest one I remembered. I forgot about the way you went about it though. Thank you for reminding me. Excellent point and great information! Thank you for sharing your experience. I have to pop into that thread again