My 1550 backhoe (for farm use) has a pretty significant engine knock. How can I determine if the knock is causes by a bearing / push rod or an injector knock? I had the head rebuilt but I'm not convinced the injector sleeves were installed properly. It is not easy to remove the oil pan to inspect the rods or bearings either. I drained the oil and found some very small metal flakes but I would anticipate there would be more if it were a bearing problem. What do you guys think?
JCB 1550 engine knock
- Thread starter Ken
- Start date
Mudandmetal
Active member
- Joined
- Oct 13, 2025
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- 27
To pinpoint that knock, grab a mechanic’s stethoscope. Injector knock sounds sharp and metallic at higher RPMs, while bearing knock is deeper and tends to worsen under load. Loosen the injectors one at a time, if the noise changes, it’s likely an injector issue. And don’t overlook metal flakes in the oil and low pressure as both can indicate bearing wear.
