Highly Recommend Bleeding the LT4 Intercooler

[hawk02]

Let me start with a rant:

Why in the heck did GM not include an intercooler reservoir on its LT4 engines? The Hellcats have one, and so do the GT500s. Why GM insists on a closed system that isn’t truly closed makes me scratch my head.

Okay, with that off my chest—I just finished bleeding the intercooler on my '23 CT5-V Blackwing. While there wasn’t a large amount of air in the system, there was still some. I used the Tapout Tuning Intercooler Fill/Bleed Kit:

Tapout Blackwing Intercooler Fill/Bleed Kit - Tapout Tuning

It’s important to note that any air pocket that reaches your intercooler pump will cause it to shut off after five seconds, rendering your intercooler worthless. This can create an unsafe scenario for a turbocharged or supercharged car, especially when boost is turned up via an aftermarket tune...

www.tapouttuning.com

When I had my ZL1, I bled the intercooler using the Dedicated Motorsports LT4 SC Coolant Filler Adapter Tool:

LT4 SC Coolant Filler Adapter Tool

Lets face it, the coolant filling system found on the LT4 supercharged Camaro ZL1 and CTS-V can be a real pain in the butt to fill. Over the years we've tried a number of different solutions but none of them did the job without some pitfalls...

dedicatedmotorsports.com

The Tapout Tuning kit makes for much less mess in terms of coolant spillage. I didn’t replace part of the intercooler hose with the clear one that comes in the kit—it’s not needed. You can tell when the pump is running and easily see bubbles rising into the coolant in the funnel.

Unfortunately, on the Global B platform, there’s no way to run the pump with the engine off. On the ZL1, you can jump the pump relay. HP Tuners or a bidirectional code reader may be able to run the pump with the engine off, but I have no evidence to back this up. I just ran the engine for about four minutes each time while depressing the Schrader valve with the wooden dowel that came in the kit. I also squeezed the intercooler hose periodically to release bubbles. I did this about four times with 5–10-minute breaks in between, then I would take the car for a drive. I repeated this procedure over three days until I was satisfied I had removed most of the air.

I plan to repeat the intercooler bleed at least once a year maybe slightly more often depending on how the car is running. No reason to lose horsepower because of air.

 

[ngoni]

I wish these were updated for Blackwings. Of course I also wish GM would design the system better from the beginning...

Intercooler Upgrade Kit (for ATS-V/LF4, CTS V-Sport/LF3)

The Caddy Issues Intercooler Upgrade Kit insures you get ALL the power your engine, upgrades, and tune can deliver! Whether your car is stock or highly modified, this drop-in, self-bleeding kit cures high Manifold Air Temperatures (MAT) and eliminates intercooler maintenance headaches!

caddy-issues.com

 

[Sully]

Let me start with a rant:

Why in the heck did GM not include an intercooler reservoir on its LT4 engines? The Hellcats have one, and so do the GT500s. Why GM insists on a closed system that isn’t truly closed makes me scratch my head.

Okay, with that off my chest—I just finished bleeding the intercooler on my '23 CT5-V Blackwing. While there wasn’t a large amount of air in the system, there was still some. I used the Tapout Tuning Intercooler Fill/Bleed Kit:

Tapout Blackwing Intercooler Fill/Bleed Kit - Tapout Tuning

It’s important to note that any air pocket that reaches your intercooler pump will cause it to shut off after five seconds, rendering your intercooler worthless. This can create an unsafe scenario for a turbocharged or supercharged car, especially when boost is turned up via an aftermarket tune...

www.tapouttuning.com

When I had my ZL1, I bled the intercooler using the Dedicated Motorsports LT4 SC Coolant Filler Adapter Tool:

LT4 SC Coolant Filler Adapter Tool

Lets face it, the coolant filling system found on the LT4 supercharged Camaro ZL1 and CTS-V can be a real pain in the butt to fill. Over the years we've tried a number of different solutions but none of them did the job without some pitfalls...

dedicatedmotorsports.com

The Tapout Tuning kit makes for much less mess in terms of coolant spillage. I didn’t replace part of the intercooler hose with the clear one that comes in the kit—it’s not needed. You can tell when the pump is running and easily see bubbles rising into the coolant in the funnel.

Unfortunately, on the Global B platform, there’s no way to run the pump with the engine off. On the ZL1, you can jump the pump relay. HP Tuners or a bidirectional code reader may be able to run the pump with the engine off, but I have no evidence to back this up. I just ran the engine for about four minutes each time while depressing the Schrader valve with the wooden dowel that came in the kit. I also squeezed the intercooler hose periodically to release bubbles. I did this about four times with 5–10-minute breaks in between, then I would take the car for a drive. I repeated this procedure over three days until I was satisfied I had removed most of the air.

I plan to repeat the intercooler bleed at least once a year maybe slightly more often depending on how the car is running. No reason to lose horsepower because of air.

What led you to bleed to system? Just doing some preventative maintenance or was there an issue?

 

[hawk02]

What led you to bleed to system? Just doing some preventative maintenance or was there an issue?

More along the lines of preventive. I owned a 6th gen Camaro ZL1 for almost seven years. In year six I decided to bleed the intercooler per recommendation of Ted Jannetty owner of Jannetty Racing. Jannetty likes to bleed the intercoolers while he has the cars on the dyno. Anyway to make a long story short, I was shocked at the amount of air I was able to remove from the ZL1 intercooler. I thought to myself these intercoolers are either filled incorrectly from the factory or over time air can enter the supposedly closed system.

My BW is over 2 years old and I thought it was a good time to check for air in the system. There wasn't as much air as was in my ZL1 but there was enough that over time it could cause pump cavitation.

 

[jbawden]

I have the Dedicated MS adaptor and a one liter bottle cut in half. It seems extra shade tree feeling, but its works.

The benefit of eliminating air in the system is to make sure the heat exchanger is providing maximum cooling affect. Not a big deal for a daily, but for track days you'll definitely want to invest in the tools as part of your track day prep.

 

[hawk02]

I have the Dedicated MS adaptor and a one liter bottle cut in half. It seems extra shade tree feeling, but its works.

The benefit of eliminating air in the system is to make sure the heat exchanger is providing maximum cooling affect. Not a big deal for a daily, but for track days you'll definitely want to invest in the tools as part of your track day prep.

I used the DMS adaptor when I bled my ZL1. It worked okay. I just didn't like the acrobatics you needed to go through to reduce the amount of coolant that gets spilled in the engine bay when you remove the adapter. The Tap Out Tuning kit has a plug for the funnel. There is much less mess and cleanup.

I will argue that bleeding the intercooler IS important even for a daily driver. MATs can rise pretty high on a 90-degree day sitting at a traffic light. Anything that will prevent or reduce timing being pulled by the ECM is worth it in my opinion.