Sapphire scientific 370ss is overheating. | TruckMount Forums #1 Carpet Cleaning Forums

Sapphire scientific 370ss is overheating.


New Member
Jun 25, 2019
Real Name
Justin J Harstad
We literally cannot figure out why the machine is overheating. It only happens after a long day and the temperature is very warm. It starts to bog down and then sounds like it wants to shut off. We replaced the governer, had the rpms measured. What would cause an air cooled engine to over heat or act like this? The repair shop has no idea and I need this monster fixed asap. Please help. :)


Well-Known Member
Nov 12, 2016
Real Name
Boris Johnson
Business Location
United States
Oh boy where to start...

I'm guessing all the usual culprits have been ruled out? Coolant is the right type and mix in the radiator, no leaks, filled to proper level?

Heat Exchangers are clean, working properly, no scale build up? Have you checked the inlet/outlet filters? Has it been de-scaled recently?

Have you looked inside the blower for any debris build up?

Why would it run all day but bog down after how many hours? Is it consistently the same amount of hours then it bogs down? Is it unusually warm in your area this time of year? Are you leaving van doors open and windows in cab down while working? Are there any obstructions to the air flow inside the van?

How old is the machine and how many hours?

Air filters in the engine and waste tank clean and good?

Justin Legend Brands

Expert Truckmount Mechanic
May 7, 2018
Real Name
Justin Johnston
Feel free to give me a call. My cell is 253-651-3468. I am tied up most of the day tomorrow, so you can also call 800-932-3030 and ask for tech support.