tpbrady
Guru
I’ve been fighting this all summer and it is getting worse. It started off randomly running more often without overheating to now randomly overheating more often than running.
It a Northern Lights M673D. Here are all the things done over the summer:
A. New coolant expansion tank and heat exchanger core and rubber boots. The generator was used and sat for a couple of years. There was a lot of loose rust.
B. New thermostat.
C. New coolant pump and hose. The old passages for the temp sensor and temp switch were full of sludge.
D. New raw water impeller and stainless exhaust elbow. The old iron elbow was starting to rot out.
E. Flushed out numerous times with Prestone coolant flush and fresh water, but would never run with coolant flush longer than an hour without overheating. These flushes have always resulting in rusty colored water being drained.
I spent about 30 minutes with Northern Lights on the phone and their conclusion was the same as mine. Something in cooling passages in the engine block interrupts the flow of coolant as the genset heats up. The genset will Star warm up to about 170 on the temp gauge and then 10 minutes or so jump from 170 to more than 200 in 15 secs or less. If I didn’t catch it in time, the temp switch would shut the generator off.
One thing we both noted when flushing the system with water without running the generator, the passages immediately after the thermostat aren’t really flushed well as the water flows from the coolant tank through the hose through the water pump into the block below the thermostat. Since I have the thermostat out I am going to flush the system both statically without running the generator and then with a coolant flush. If I solve this I hope to have my generator cooling system training record signed off. If AI has a better suggestion, I am open to it.
Tom
It a Northern Lights M673D. Here are all the things done over the summer:
A. New coolant expansion tank and heat exchanger core and rubber boots. The generator was used and sat for a couple of years. There was a lot of loose rust.
B. New thermostat.
C. New coolant pump and hose. The old passages for the temp sensor and temp switch were full of sludge.
D. New raw water impeller and stainless exhaust elbow. The old iron elbow was starting to rot out.
E. Flushed out numerous times with Prestone coolant flush and fresh water, but would never run with coolant flush longer than an hour without overheating. These flushes have always resulting in rusty colored water being drained.
I spent about 30 minutes with Northern Lights on the phone and their conclusion was the same as mine. Something in cooling passages in the engine block interrupts the flow of coolant as the genset heats up. The genset will Star warm up to about 170 on the temp gauge and then 10 minutes or so jump from 170 to more than 200 in 15 secs or less. If I didn’t catch it in time, the temp switch would shut the generator off.
One thing we both noted when flushing the system with water without running the generator, the passages immediately after the thermostat aren’t really flushed well as the water flows from the coolant tank through the hose through the water pump into the block below the thermostat. Since I have the thermostat out I am going to flush the system both statically without running the generator and then with a coolant flush. If I solve this I hope to have my generator cooling system training record signed off. If AI has a better suggestion, I am open to it.
Tom