Engine failure root cause
If you’re following us on social media (you can do so HERE if not), you probably saw our post earlier this week showing a John Deere emergency fire pump engine in our workshop that needed urgent attention:
The water hose had failed (which is a common fault on these engines), so the operator called in their service company for a replacement.
The hose and thermostat were replaced as expected, but no other investigation was carried out on the engine before it was run again.
After less than 30 seconds, the unit had to be shut down due to a severe knocking noise. And when the attending engineer took a look at the engine discolouration, he could see a full overhaul was required.
Unfortunately, they couldn’t fit this in for at least a month, so – due to the urgency of the work – we were called in.
Our engineers were quickly on-site, found water in the oil and suspected a hydraulic piston. The engine wouldn’t bar over and they were amazed that the conrod hadn’t ejected itself out of the side of the crankcase!
The engine is now at our workshop and is undergoing a full and thorough overhaul to ensure it can be relied upon again and is back on-site ASAP.
As you can see from the pictures above, the operator had avoided a catastrophic failure – two of the conrods had reached such a high temperature they had melted and one of the pistons had seized completely.
You can also see the damage caused to the pushrod which was moments from disaster.
Gary, our senior machinist is measuring the case and e bores to ensure they have not warped and can be re-used. If not, we will machine them as long as they will remain within OEM tolerances.
Along with the complete overhaul, we’ll be retrofitting a water level indicator to the existing gauge panel for clearer visibility and reliable monitoring to alert if this type of issue occurs again.
What started as a simple issue, went from hose replacement to full overhaul, and narrowly avoided the need for a replacement engine.