BOLT 7W4634 - Caterpillar

Marine Engine: 3412E MARINE (S/N: 9KS1-UP) C32 MARINE (S/N: RXB1-UP; SLT1-UP)Introduction
The problem that is identified below is not a Caterpillar design or material issue. Vessels have design, application, or installation issues that do not meet Caterpillar guidelines. These issues induce unacceptable strain into the cylinder block. Due to the many variables that can contribute to these issues, this problem does not have a permanent solution. Until a permanent solution is found, use the solution that is identified below.Problem
Steps to Help Identify the Coolant Leak
If a customer complaint is coolant loss, coolant in lube oil (emulsified oil), or oil sample Scheduled Oil Sampling (S O S) results are positive for water, Glycol, or a supplemental coolant additive, then follow the standard troubleshooting procedure as outlined in Troubleshooting, SENR5015-04, "Coolant in Oil"If the troubleshooting leads to the final step "Cylinder Block" then perform the following steps:
Make sure that coolant leak detection dye is in the coolant and that the engine has been operated long enough to reach operating temperature.
Illustration 1 g02030213
(1) Cylinder 10 (2) Cylinder 9 (3) Crack
Pressurize the cooling system. Remove the oil pan and use a black light to observe the water crossover at bulkhead 6 between cylinder 9 (2) and cylinder 10 (1). Refer to Illustration 1.
If a crack (3) is confirmed in the cylinder block in this area, then contact your dealer Technical Communicator and your local Caterpillar Dealer Service Representative for further instruction and investigation direction.Solution
Actions
Once confirmation of a cracked block in this area has been identified it is extremely important that the owner and the captain of the vessel are notified that an extensive investigation of the vessel and engine installation needs to be performed in order to identify any vessel design, application, or installation issues that may have contributed to the cracked block failure.In order to allow the necessary time to investigate the issue, a cooling system stop leak such as CarGo brand "Seal-Up 1116", or an equivalent, should be used. This will allow extended operation of the engine up to 1500 hours without contaminating the lube oil with coolant while the investigation takes place on the vessel.Note: It is critical that the owner or the operators of the vessel understand that it is their responsibility to frequently monitor the lube oil should the engine continue to be operated on a regular schedule. Use the Scheduled Oil Sampling (S O S) program in order to ensure that the coolant leak has stopped and ensure that the lube oil is not being contaminated during the time of the investigation.