Thermocouples May Fail on Certain G3500 Engines {7498} Caterpillar

Engine

G3508 (S/N: CPJ1-UP; WPN1-UP; DLR1-UP; CPS1-UP)

G3508B (S/N: RBK1-UP)

G3512 (S/N: CRN1-UP; CSP1-UP; WPP1-UP; WPR1-UP; GNS1-UP)

G3512B (S/N: JHH1-UP)

G3512E (S/N: GFM1-UP; SSR1-UP; NGS1-UP; SST1-UP)

G3512H (S/N: GF51-UP)

G3516 (S/N: SB31-UP; AL71-UP; L6A1-UP; N6A1-UP; ZBA1-UP; N6B1-UP; N6C1-UP; L6E1-UP; L6F1-UP; L6G1-UP; 4EK1-UP; WPS1-UP; WPT1-UP; WPW1-UP; ZAZ1-UP)

G3516B (S/N: ZBB1-UP; N6E1-UP; JEF1-UP; L6H1-UP; L6J1-UP)

G3516C (S/N: GSB1-UP; GZC1-UP; F6D1-UP; F6E1-UP; F6F1-UP; F6M1-UP; GZZ1-UP)

G3516E (S/N: F6G1-UP; GAS1-UP)

G3516H (S/N: NWH1-UP; NWJ1-UP; GLM1-UP; GLN1-UP)

G3520B (S/N: GLF1-UP)

G3520C (S/N: GZA1-UP; GZB1-UP; GZJ1-UP; GZL1-UP; GZM1-UP; GZN1-UP; RLP1-UP; LGS1-UP)

G3520E (S/N: GZE1-UP)

G3520H (S/N: GFP1-UP; GFR1-UP)

Petroleum Engine

G3520B PETROLEUM (S/N: TPC1-UP)

Introduction

The following changes are adaptable to the products within the listed serial numbers, and are effective with all products after the listed serial numbers.

Problem

Gas engines with thermocouples are displaying erratic or no output readings in regions across the world. Many of the analyzed thermocouples have shown signs of overheating.

Solution

Ensure that the thermocouples are not covered by any type of insulation or wrap that will prevent cooling from circulating air.