2018-2025 Equinox & Terrain 1.5L Intercooler: Fixing Power Loss from Icing and Moisture

Symptoms of a Failing Intercooler

A problem with the charge air cooler on a 2018-2025 Chevrolet Equinox or 2018-2024 GMC Terrain will cause noticeable performance issues. The symptoms are often related to the turbocharger's inability to supply the engine with the proper amount of cooled, compressed air.

• Loss of Engine Power: This is the most common symptom. The vehicle may feel sluggish, accelerate slowly, and may enter a "Reduced Engine Power" or "limp mode."
🎬 Watch: Real-life example of an Equinox losing power on the highway
• Check Engine Light: A faulty intercooler will almost always trigger a check engine light. The most common trouble code is P0299 (Turbocharger Underboost). You may also see codes P2227 (Barometric Pressure Sensor Performance) or P0300 (Random Misfire), especially if the failure is related to moisture inside the cooler.
• Hissing or Whistling Noises: A leak in the intercooler or its connecting hoses can produce a distinct hissing or whistling sound that gets louder with acceleration as boost pressure builds.
• Poor Fuel Economy: When the engine isn't receiving properly cooled air, the engine's computer tries to compensate, often leading to richer fuel mixtures and a noticeable drop in MPG.
• Black Smoke from Exhaust: In some cases, a significant boost leak can cause the engine to run rich (too much fuel, not enough air), resulting in black smoke from the tailpipe during acceleration.

Known Issues, TSBs, and Recalls

There are no specific recalls for the intercooler on these vehicles. However, there is a very well-documented issue concerning moisture and oil collecting inside the charge air cooler, which is addressed by several General Motors Technical Service Bulletins (TSBs).

TSB: Moisture Buildup, Icing, and Misfires

The most significant known issue for the 1.5L turbo engine in the Equinox and Terrain is the accumulation of moisture inside the charge air cooler. This moisture comes from the Positive Crankcase Ventilation (PCV) system and high ambient humidity.

• In Cold Weather: During freezing temperatures (especially below 32°F / 0°C), this collected moisture can freeze solid, creating a blockage. This prevents the turbo from pushing air into the engine, leading to a P0299 underboost code and a severe loss of power.
• In Humid/Wet Weather: Even in warmer weather, moisture can pool inside the cooler during long drives in high humidity or rain. A sudden, hard acceleration can suck a "slug" of this water into the engine, causing a violent shudder and setting a P0300 random misfire code.

GM has released multiple TSBs to address this, including #18-NA-020, #22-NA-002, and #22-NA-065. The recommended repair procedure varies depending on the vehicle's build date.

• For vehicles built before March 1, 2018: The TSB often recommends replacing the original charge air cooler with an updated part (GM P/N 85163204 or similar).
• For later models or as an additional measure: Fixes may include reprogramming the Engine Control Module (ECM) to adjust transmission shift patterns to keep engine RPMs higher, which helps reduce moisture buildup. Other procedures involve installing a lower grille cover or a thermal wrap for the turbocharger wastegate solenoid valve.

Buying a Used Intercooler: What to Check

A used OEM intercooler can be a cost-effective solution, especially since the primary issue is often moisture accumulation rather than a defect in the part itself. However, careful inspection is crucial.

1. Check for Physical Damage: The intercooler sits at the front of the vehicle and is vulnerable to impacts from road debris. Carefully inspect the cooling fins. A few bent fins are acceptable, but widespread damage or crushed sections will reduce its effectiveness. Check the plastic end tanks for any cracks, especially around the seams where they are crimped to the aluminum core.
2. Inspect Inlet and Outlet Ports: Look inside the inlet and outlet ports for signs of heavy, thick, oily sludge. A light oil film is normal for any turbocharged engine, but a thick, milky, or watery oil residue indicates the vehicle it came from had the common moisture accumulation problem.
3. Check for Internal Blockages: Hold the intercooler up and try to look through it. While you can't see all the way through, you can check for obvious debris. Gently shake it to listen for any loose items rattling inside. If possible, pour a small amount of isopropyl alcohol into one end and see if it drains freely from the other. This can help flush out any residual moisture and check for clogs.
4. Verify Part Number: If possible, try to get an intercooler with one of the later, updated OEM part numbers like 85046823 or 85163204, as these may have design revisions.

Replacement Overview & Difficulty

Replacing the intercooler on a 2018-2025 Equinox or Terrain is a moderately difficult job that is feasible for an experienced DIY mechanic.

• Difficulty Rating: 3 out of 5
• Estimated Time: 2.5 - 3.5 hours
• DIY Feasible: Yes, for those comfortable with body panel removal.

The most time-consuming part of the job is removing the front bumper cover to gain access. The general steps involve:

1. Disconnecting the battery.
2. Removing screws in the wheel wells and under the front of the vehicle to detach the bumper cover.
3. Carefully unplugging any sensors or lights attached to the bumper cover before setting it aside.
4. Unclamping the charge air hoses from the intercooler inlet and outlet.
5. Unbolting the intercooler from its mounts and removing it from the vehicle.
6. Installation is the reverse of removal. Be sure to securely tighten all hose clamps to prevent boost leaks.
🎬 Watch this step-by-step guide to replacing the intercooler yourself

Cost Comparison

The cost to replace the intercooler can vary significantly based on the parts you choose and whether you perform the labor yourself.

Frequently Asked Questions (FAQ)