2003/05/01 Caterpillar

Marine Engine:

3126B (S/N: 9ZF1-UP; 3GS1-UP)

3196 (S/N: 2XR1-UP)

3406E (S/N: 9WR1-UP)

3412E (S/N: 9KS1-UP; 9PW1-UP)

C9 (S/N: CSN1-UP)

C12 (S/N: 9HP1-UP)

C18 (S/N: CKH1-UP)

C30 (S/N: CLX1-UP)

Exhaust temperatures are acquired in order to verify engine performance. The following may cause inaccurate temperature readings: incorrect type of thermocouple and incorrect placement of the thermocouple.

In order to measure the exhaust temperature, use a Type K thermocouple. The thermocouple should have a 6.35 mm (0.250 inch) diameter and a locking ferrule. The thermocouple must have a working length of 125 mm (4.9 inch). Use this thermocouple in the 1/4" NPT port in the flange for the exhaust manifold. This port is located upstream of the turbocharger. Use the following steps in order to install the thermocouple:

Illustration 1	g00991507
(1) Flange for exhaust manifold (2) Thermocouple (3) Ferrule adapter

1. Insert the ferrule adapter (3) into the manifold. Tighten the ferrule adapter (3) .

2. Slide the Type K thermocouple (2) into the ferrule adapter (3). Leave the thermocouple (2) loose.

3. Connect the thermocouple (2) to 6V-9129 Temperature Adapter Gp or a similar temperature indicator.

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Avoid contact with hot surfaces. Exhaust piping and engine components become hot during engine operation and cool slowly after engine shutdown. Any contact with hot surfaces can cause severe burns.

4. Operate the engine between 1/3 and 1/2 throttle.

5. Slide the thermocouple (2) in and out of the flange for the exhaust manifold (1). Find the location that will provide the highest temperature reading.

6. Tighten the thermocouple (2) in order to retain this position.