Cracked Intake Manifolds. Dex-Cool To Blame?

Many GM Vehicles Have Cracked Intake Manifolds Due to Corrosion

Leaking coolant from a cracked intake manifold gasket is an extremely common problem on most GM vehicles made from the late 90s to the mid–2000s. Most experts agree that the problem stems from GM’s “DexCool” coolant, which reacts with the intake manifold gasket, causing it to leak coolant.

Dex-Cool's Effect on the Intake Manifold Gasket

Dex-Cool is a type of coolant that many Chevrolet owners claim is corrosive and eats up critical engine parts like the heater core, radiator and water pump.

Several class action lawsuits have been filed, both in the U.S. & Canada. However even statewide class action lawsuits have been running into trouble. State courts in Michigan and California already have rejected class action status for Dex-Cool lawsuits.

Replacing the intake manifold gasket usually costs between $700 - $1,000, mostly labor. GM has updated the material used in the intake manifold gasket so that it doesn’t react with the Dex-Cool coolant as fast as the original gasket material. Currently there is no recall for the intake gasket, because it is not a safety issue (at least according to the NHTSA[1]).

GM Vehicles Most Affected

Make Model Generation Years
Chevrolet Malibu 5th generation 1999, 2000, 2001, 2002, 2003
Pontiac Grand Am 5th generation 1999, 2000, 2001, 2002, 2003, 2004, 2005

Federal Judge Rejects Dex-Cool Class Action Lawsuit

The push for a national class action lawsuit against GM for problems related to their Dex-Cool coolant suffered a setback Friday, when a U.S. federal judge ruled that national class action status would be too complicated.

U.S. District Court Judge G. Patrick Murphy rejected the Dex-Cool class action by ruling that the magnitude of the class action, combined with the wide array of state laws involved, would make it impossible to cover all claims under one national class action. The decision can be appealed, but GM vehicle owners may ultimately be forced to pursue claims either in statewide class actions or as individual cases against General Motors.

The class action contends that in over 35 million GM vehicles manufactured from 1995 to 2004, GM’s “Dex-Cool” coolant caused serious car problems such as plugged radiators from coolant sludge, as well as head gasket and intake gasket failure possibly resulting in engine damage. GM marketed Dex-Cool coolant as good for 150,000 miles or 5 years without needing to be flushed and replaced with new coolant.

The law firms involved are seeking national class action status to include plaintiffs from 47 U.S. states. A number of statewide class action lawsuits have been filed, although two of those have been rejected already in Michigan and California. Another class action goes to trial in Missouri in November 2007.

Dex-Cool Class Action Law Firms

Actions You Can Take

This step is crucial, don't just complain on forums! The sites below will actively manage your complaints and turn them into useful statistics. Both and the CAS will report dangerous trends to the authorities and are often called upon by law firms for help with Class Action lawsuits. Make sure to file your complaint on all three sites, we can't stress that enough.

  1. Step 1: File Your Complaint at is a free site dedicated to uncovering problem trends and informing owners about potential issues with their cars. Major class action law firms use this data when researching cases. Add a Complaint

  2. Step 2: Notify the Center for Auto Safety

    The Center for Auto Safety (CAS) is a pro-consumer organization that researches auto safety issues & often compels the US government to do the right thing through lobbying & lawsuits. Notify the CAS

  3. Step 3: Report a Safety Concern to NHTSA

    The National Highway Traffic Safety Administration (NHTSA) is the US agency with the authority to conduct vehicle defect investigations & force recalls. Their focus is on safety-related issues. Report to NHTSA

  1. NHTSA stands for the National Highway Traffic Safety Administration  ↩

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Chevrolet Customer Assistance Center

P.O. Box 33170 Detroit MI 48232-5170