Duramax Diesel Exhaust Isolator No Longer in Production

A missing exhaust isolator (Fig. 5) on 2020 Silverado and Sierra models equipped with the 3.0L Duramax diesel engine (RPO LM2) and the single exhaust system (RPO NB5) should not be installed as part of a warranty claim at the dealership.


Fig. 5


The exhaust isolator is no longer installed in order to address a noise concern. However, the exhaust hanger on the frame and the hanger on the exhaust pipe are still in production. The exhaust hanger on the other side of the exhaust pipe near this location is still connected. (Fig. 6) These changes went into effect at the Fort Wayne assembly plant on June 17, 2020 and are part of the continuous product improvement process. Light-duty trucks with the diesel engine and single exhaust built at the Silao assembly plant have not yet removed the isolator from production.


Fig. 6


The exhaust hanger was communicating an exhaust boom due to a structural vibration. Without the isolator connecting the exhaust pipe to the hanger, the boom sound is eliminated. At the same time, it was determined that the hanger is not needed at that location on the exhaust pipe and that durability and the function of the exhaust are unaffected.

If an exhaust isolator is installed on the exhaust pipe and connected to the hanger, the exhaust boom sound may be heard. A warranty claim should not be submitted for installing the exhaust isolator.

TIP: The Electronic Parts Catalog may show the eliminated exhaust hanger on the single exhaust pipe. The catalog is currently being updated to remove the hanger.

– Thanks to David MacGillis

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