Jet Vet

I have tracked my '15 Z51 A8 for 18 months now and I finally fixed the transmission oil overheat problem. After waiting in vain for GM to put out a solution, two months ago I installed LG's larger cooler in place of the OEM unit. The procedures and my results are in a thread here:

https://www.corvetteforum.com/forums...8-install.html

That 'stage 1' installation helped, but not enough, so I recently had my speed shop perform the 'stage 2' upgrade by installing the OEM unit as a secondary cooler, fabricating a bracket and mounting it under the rear transverse member, then splicing the two new lines into the main system return line. The coolant flow is now routed from Transmission to Primary (Large) Cooler to Secondary (OEM) Cooler and back to Transmission.

This weekend was a real trial by ordeal. The ambient temp at NOLA track was 95 both days, with 85% humidity, a heat index of well over 100 and a track surface temp of over 125. In the first 20 min. session each day the tranny temp maxed out at 225, some 30 degrees lower than previously. The second session, where the tranny oil temp started much warmer than the first, it maxed out at 235, still well below the red line of 275. The third and fourth sessions were a repeat of the morning, with the oil having cooled more over a long lunch break before session three, then warmer at the start of session four.

Considering the brutal conditions, these results were a pleasant surprise indeed.

JV

robert miller

Glad to see you have it under control man. This should help the guys on the track for sure with those temp's in it now.

Chets LS3

Possibly the most brutal or close to it track temps in the country down at Nola this weekend.

Glad it's running like a champ!

Jay_Davis

The original thread talks about a stage 2 and stage 3, with stage 3 being both coolers. Has that changed?

Do you or LG know how their full solution compares to up-front secondary cooler that GM put on the 2016 cars?

X25

If you haven't already, I'd highly recommend checking the transmission fluid level again. The system only works the air out of the lines and into the transmission, once the system worked at revs higher than idle. Once the air is removed, it is left stuck inside the transmission, causing unnecessary positive air pressure inside. I had this issue on both with my Camaro Z/28 diff cooler, and my Z06 transmission cooler upgrade for my Z51. Moreover, there was positive pressure in the system even with the factory fill; it's not easy for the factory to work it out in production, either.

Jet Vet

I thought that stage 1 was replacing the original cooler with the larger one, stage 2 was that plus adding the original cooler as secondary in the rear, and stage 3 was 1 & 2 plus LG's larger oil pan, which isn't available for the A8 yet. I could be wrong about the designations, but it really doesn't matter to me which is called which. I don't have any comparative data for GM's front cooler, I just know that mine was a pretty simple and effective solution.

JV

Thanks, I'll check that out.

JV

cajunboyz

Great info, As I do also live here in this High Humidity HEAT NOLA