99.022a Nitrited Organic Acid (NOAT) and Organic Acid (Dexcool) Problems in Engines


Cummins® Engine Company is warning its customers not to use Texaco® Extended Life (NOAT) engine coolant. Truck and bus manufacturers have stopped filling all Cummins engines with NOAT coolant. Problems have been documented that affect silicone seals and other cooling system problems. Penray has suspended its development of competitive NOAT technologies in light of this very serious situation.

NOAT Problems and Corrective Actions:

NOAT coolants are reported to be triggering various cooling system problems, including coolant leaks due to silicone engine seal degradation, aluminum radiator failures, and plugging of radiators in general, especially if NOAT coolants are mixed with traditional (green) or advanced fully-formulated (pink or green) technologies. Cummins instructs that Texaco Extended Life Coolant poses a risk to all Cummins brand engines. Cummins has reported problems in Caterpillar® and GM® engines. Caterpillar continues to support NOAT and has objected to Cummins’ report.

Cummins sent a detailed letter to its customers notifying them that Cummins will not cover repair costs related to the use of NOAT. Instead, warranty and repair cost issues should be directed to Texaco. “It is the responsibility of the manufacturer of such products to ensure compatibility with engines and cooling systems in the marketplace”.

Damaged systems will eventually fail, but the failure may be delayed by draining, flushing and refilling them with fully-formulated advanced technology coolants that meet TMC RP-329 (or TMC RP-330) or the equivalent ASTM D-6210/D-6211 coolant specifications.