Thermoplastic molding composition comprises (in parts by wt.): (a) at least one polyamide or copolyamide (25-79.85), (b) at least one copolymer of at least one olefin (0.05-10) and at least one acrylic acid ester of an aliphatic alcohol, where the melt flow index of copolymer is greater than 10 g/10 minute, and a test weight of 2.16 kg is measured or determined according to ISO 1133at 190[deg] C, (c) at least one filling- and reinforcing material (10-65), and (d) at least one oligomeric or polymeric carbodiimide (0.05-10). Independent claims are also included for: (1) a use of a combination of at least one copolymer of at least one olefin and at least an acrylic acid ester of an aliphatic alcohol and at least one oligomeric or polymeric carbodiimide, in polyamide-based thermoplastic molding compositions for improving the hydrolysis resistance of polyamide-based products, where the copolymer has an melt flow index of greater than 10 g/10 minute, preferably greater than 300 g/10 minute; and (2) preventing hydrolysis and/or glycolysis in components of motor vehicle-cooling circuit, comprising employing polyamides comprising thermoplastic molding composition for preparing of the components.