Hello everyone, We recently encountered an exhaust system failure on a Caterpillar C175-16 engine. The problem began with the thermal blanket showing signs of severe internal burn, and after removal, we found the exhaust pipe had a visible crack, likely causing hot exhaust gases to escape and deteriorate the insulation from the inside. Here are the key observations: - The crack seems to be located at or near a weld joint - The insulation was high-quality and properly installed. - No engine codes or alerts were logged before the failure. - The engine operates in frequent start/stop cycles under variable load conditions. We are currently investigating the root cause, considering: - Thermal fatigue from repeated heating and cooling cycles. - Mechanical vibration or inadequate support of the exhaust system. - **Internal corrosion or substandard welding. - Possible backpressure due to downstream restriction. If anyone has seen similar issues with the C175-16 or similar models, your insights would be appreciated
What is the engine used for?
Locomotive
Some pics of this crack may help
At how many engine hours did the symptoms present themselves.? Is it an original engine in a new locomotive or a replacement engine that has been installed later in life.? If it is a replacement engine is the exhaust pipe that cracked part of the original locomotive installation or did they come with the engine.? Engine Serial Number and Part Number that failed would be useful. How many of these engines you have and how many exhuast pipe failures have occured to date would also be pertinent.
Thanks, it's a new one with less than two years in operation.
We have 12 units and it was the only one
How many operating hours.? Help us to help you. Need the engine Serial Number (3B9-something.?) and the Part Number of the exhaust pipe that failed. Another question along the same lines. Is the exhaust tube that failed actually a Caterpillar part or is it supplied by the locomotive manufacturer.? Let me rephrase that. It is the only one "so far".
3B90xxx – I hope you understand, but I prefer not to disclose the full serial number. I am investigating failures in comparable equipment and I believe the C175-16 model provides sufficient reference for this purpose. Any information on recurring issues or known failure modes in similar ones would be very helpful to identify the most likely root cause. Thanks a lot.
I understand completely. Send me the details of the full Serial Number via a private message if you like. Still need answers regarding the engine operating hours at time of failure and whether or not the tube that failed is a Caterpillar part or is supplied by the locomotive manufacturer. I did take a brief look at the 3B9 engine setup and did not see anyting resembling what is shown in your photos. This led me to believe that the tube may not be a Caterpillar part. Without more information my search capabilities are limited.
Please report it to your CAT dealer with photos, ask to send the info to a Technical Communicator . Include all the info about serial, use type, use cycles, etc Their report of failed parts is what starts the ball rolling on CAT investigating. If this is not a one-off failure, as more reports come in they may start a case on finding out why and what to change. This is how service letters, for example, are concieved, along with production changes.
I’m still trying to get to the bottom of whether or not the tube that failed is even a Cat part. The photos illustrate what happened but there is nothing from further away to serve as location context. It may be a part supplied by the locomotive manufacturer.
As to a locomotive engineering aspect, I wouldn’t find it reasonable to think Cat would have designed and especially made the exhaust.
Agreed, but generally on this type of engine the first section of the “exhaust” as it leaves the turbocharger is generally, although not always, supplied as part of the engine for obvious reasons.