What the diverter valve does and why it fails

The diverter valve on your 2020 Chevy Trax sits between the turbocharger and the intake manifold. When you lift off the throttle, it vents excess boost pressure to prevent compressor surge — a condition that can damage the turbo. A failing diverter valve either sticks open (causing boost loss and rough idle) or sticks closed (causing a loud whistling sound and reduced power).

Most diverter valves fail because the internal spring weakens or carbon buildup prevents the valve from sealing. On the 2020 Trax with the 1.4L turbo engine, the part itself costs between $80 and $150 depending on whether you buy OEM or aftermarket. Labor at a shop runs $200 to $400. The job takes about 45 minutes to an hour if you have basic mechanical experience and the right tools.

Key Takeaways

  • The diverter valve sits on top of the engine near the turbocharger intake and can be reached without removing the turbo itself.
  • You will need a socket set, a breaker bar, a hose clamp tool or pliers, and either an OEM GM part number 55573050 or a quality aftermarket equivalent.
  • The hardest part is disconnecting the vacuum hose and boost line without cracking the fittings — work slowly and explore penetrating oil if anything is stuck.
  • After installation, reconnect all hoses in the exact same positions, tighten the bolts to 18 foot-pounds, and start the engine to check for vacuum leaks before driving.

Gather your tools and parts before you start

You will need a socket set (10mm, 13mm, and 15mm sockets), a breaker bar or ratchet, a screwdriver set, pliers or a hose clamp removal tool, and penetrating oil like PB Blaster or Kroil. Have a small drain pan ready in case coolant spills — the diverter valve sits near coolant lines, though the valve itself does not hold coolant.

For the part itself, order GM part number 55573050 (the OEM diverter valve for the 2020 Trax 1.4L turbo) or a trusted aftermarket brand like Dorman or ACDelco. Do not buy the cheapest option on the internet — a weak replacement will fail again in 20,000 miles. The OEM part is worth the extra $30 to $40.

Let the engine cool completely before you start. The diverter valve sits inches from the turbocharger, which stays hot for 10 to 15 minutes after shutdown. Burn risk is real.

Locate the diverter valve and remove the intake ducting

Open the hood and look at the top of the engine. The diverter valve is a cylindrical part about 3 inches long, mounted on a bracket above and to the right of the turbocharger. You will see a vacuum hose and a boost pressure line connected to it.

Remove the plastic intake duct that runs from the air filter box to the turbo inlet. This duct is held by a hose clamp at each end — loosen both clamps with a 10mm socket or screwdriver and slide the duct away. You do not need to remove the air filter box itself. This step gives you room to work and prevents you from accidentally disconnecting the wrong hose.

Disconnect the vacuum and boost lines carefully

The diverter valve has two connections: a small vacuum hose on the bottom and a larger boost pressure line on the side. The vacuum hose usually pulls straight off by hand, but the boost line is a threaded fitting that requires a wrench. Before you touch either one, take a photo with your phone so you remember which hose goes where.

Spray penetrating oil around both fittings and wait five minutes. Use a 13mm wrench on the boost line fitting while holding the valve body steady with your other hand — do not let the valve twist, or you risk cracking the fitting that screws into the engine. Turn slowly. If it does not budge after 30 seconds of steady pressure, spray more oil and wait another five minutes. Forcing a stuck fitting is how you end up with a broken valve body and a much bigger repair.

Once the boost line is loose, unscrew it by hand. The vacuum hose should pull straight off. Set both aside and plug the boost line fitting with a clean rag so dirt does not enter the turbo system.

Remove the mounting bolts and lift out the old valve

The diverter valve is held to its bracket by two bolts: one 10mm bolt on the front and one 13mm bolt on the back. Use a socket and breaker bar to loosen both, then finish by hand. The valve will come free once both bolts are out. If it sticks, gently pry it with a screwdriver — do not hammer or yank.

Inspect the mounting bracket for cracks or corrosion. If the bracket looks damaged, you may need to replace it as well, though this is rare. Clean the bracket with a wire brush to remove any carbon or debris, then wipe it clean with a rag.

Install the new diverter valve and reconnect everything

Position the new valve on the bracket and hand-start both bolts. Once both are finger-tight, use a socket and torque wrench to tighten them to 18 foot-pounds. Do not over-tighten — the valve body is aluminum and cracks easily. If you do not have a torque wrench, tighten until snug and then stop; most people's "snug" is close enough for this job.

Reconnect the boost line first by screwing the fitting back into the side of the valve. Use your 13mm wrench to hold the valve steady while you turn the fitting clockwise by hand. Tighten it firmly but do not use a wrench to over-tighten — hand-tight plus a quarter turn is enough. Reconnect the vacuum hose to the bottom of the valve by pushing it straight on until it seats.

Reinstall the intake duct and tighten both hose clamps. Start the engine and listen for a vacuum leak — a hissing sound near the diverter valve means one of your connections is not sealed. If you hear hissing, shut the engine off, let it cool, and re-seat the hose or tighten the boost line fitting another quarter turn.

Test the new valve and watch for warning signs

Let the engine idle for two minutes, then rev it gently to 2,000 RPM and listen for the diverter valve to click or chirp — this is normal and means the valve is opening and closing as it should. If you hear nothing, the valve may not be getting vacuum signal, which usually means the vacuum hose is not fully seated.

Drive the car gently for the first 10 miles. You should feel normal turbo boost and hear no unusual whistling. If the check engine light comes on, the boost pressure sensor may have been disturbed during the job — this usually clears after a few drive cycles, but if it stays on, you may need to have the sensor connection checked.

If the rough idle or boost loss returns within a few hundred miles, the new valve is defective and should be replaced under warranty. Keep your receipt.

Frequently Asked Questions

Can I drive the car if the diverter valve is broken?

Yes, but not for long. A stuck-open valve causes rough idle and poor fuel economy. A stuck-closed valve causes turbo surge and can damage the compressor wheel. Driving more than a few hundred miles with a failed diverter valve risks a $1,500+ turbo replacement, so fix it soon.

What if I crack the boost line fitting while removing it?

Stop when ready and do not start the engine. A cracked fitting will leak boost pressure and cause a check engine light. You will need to replace the entire boost line assembly, which costs $150 to $250 and takes another hour. This is why penetrating oil and patience matter — a cracked fitting is expensive to fix.

Do I need to replace the vacuum hose too?

Only if it is cracked, brittle, or does not hold a seal when you reconnect it. Most vacuum hoses last the life of the car. If the hose looks fine, reuse it. If it is hard or cracked, replace it with a new one from the dealer — it costs $15 to $25.

Will this job trigger a check engine light?

Not usually, but disconnecting the boost pressure sensor during removal can set a code. This typically clears after a few drive cycles. If the light stays on after 50 miles of driving, have the boost sensor connection checked — it may have come loose during the job.

How long does the new valve last?

A quality OEM or name-brand aftermarket valve should last 100,000 miles or more. Cheap aftermarket valves sometimes fail within 20,000 miles. The extra $30 for an OEM part is insurance against doing this job twice.