Help, please! Engine overheating 🥵

[atomsplitter]

Air in the pump would be the only way it could be air bound. Water not circulating has two possibilities, one the pump isn't pumping, two the thermostat is failed shut. Another possibility is the pump impellor imploded and the debris is restricting flow. I had that happen on an outboard motor once and it was hell finding the problem (new water pump didn't solve the overheating).

 

[Journeyman]

Yeah, I'm leaning away from the PWM Controller. The code indicated the Coolant Temperature Sensor, but wondering if that just means it did its job indicating a problem, or if the sensor itself is bad.

My hunch though goes back to air in the system. Wondering if the overflow tank were too low, then I topped it off while cold, then took the bike for a ride, if in the process of drawing fluid from the overflow tank if air might not have been introduced- maybe by the empty hose drawing on the newly available fluid. Also, the radiator cap was not hot, so it suggests water wasn't circulating. I was moving at about 40 mph when this happened.

This all began immediately after I added coolant to the overflow tank. Of course there are always coincidences in the timing of things.

After towing the bike home and reading the code I did open the radiator cap and let it idle a while and it was fine. I'm going to take the bike out now after a long idle and see what happens next.

 

[Nashvegas]

Yeah, I'm leaning away from the PWM Controller. The code indicated the Coolant Temperature Sensor, but wondering if that just means it did its job indicating a problem, or if the sensor itself is bad.

My hunch though goes back to air in the system. Wondering if the overflow tank were too low, then I topped it off while cold, then took the bike for a ride, if in the process of drawing fluid from the overflow tank if air might not have been introduced- maybe by the empty hose drawing on the newly available fluid. Also, the radiator cap was not hot, so it suggests water wasn't circulating. I was moving at about 40 mph when this happened.

This all began immediately after I added coolant to the overflow tank. Of course there are always coincidences in the timing of things.

After towing the bike home and reading the code I did open the radiator cap and let it idle a while and it was fine. I'm going to take the bike out now after a long idle and see what happens next.

Did it gurgle or burp when you had the cap off idling? Did the water get pretty warm? I hope it was just air.

 

[imcool]

thanks so much

It’s a 12V automotive BLDC fan controller module (8-pin interface) with PWM + enable control.
A 3-phase BLDC motor driver + PWM control IC + MOSFET power stage

Pin meaning

• RED (+) → Battery +12V supply
• BLACK (-) → Ground
• BLUE (PWM IN) → Speed control signal (duty cycle input)
• YELLOW (ENABLE) → ON/OFF logic gate
• WHITE (+) → often tach feedback or secondary signal
  
  
  I am digging around to find replacement aftermarket, lets see

I found the alternate, but this will require punching/crimping of connectors (which is not that hard) , this module is only $60USD and twice as powerful/capable compare to triumph OEM $260 USD

Amazon.com: uxcell 1 Set No.8E0959501AG/8E0959501AB/8E0959501K Radiator Engine Cooling Fan Control Unit Module Controller for Audi A4 1.8L 3.0L 2002-2005 : Automotive

Buy uxcell 1 Set No.8E0959501AG/8E0959501AB/8E0959501K Radiator Engine Cooling Fan Control Unit Module Controller for Audi A4 1.8L 3.0L 2002-2005: Electric Controls - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Nashvegas]

I found the alternate, but this will require punching/crimping of connectors (which is not that hard) , this module is only $60USD and twice as powerful/capable compare to triumph OEM $260 USD

Amazon.com: uxcell 1 Set No.8E0959501AG/8E0959501AB/8E0959501K Radiator Engine Cooling Fan Control Unit Module Controller for Audi A4 1.8L 3.0L 2002-2005 : Automotive

Buy uxcell 1 Set No.8E0959501AG/8E0959501AB/8E0959501K Radiator Engine Cooling Fan Control Unit Module Controller for Audi A4 1.8L 3.0L 2002-2005: Electric Controls - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Nice find!

 

[Journeyman]

Did it gurgle or burp when you had the cap off idling? Did the water get pretty warm? I hope it was just air.

No, nothing dramatic like that. Maybe once it cooled down and bounced around on the trailer it burped like patting a baby on its back.

Earlier, I let it idle till the fans kicked on, and more, and it stayed in range. Just got back from about a 20 mile ride and also kept in range. I'm going with and hoping for my idea that it sucked in air when it drew from the overflow tank, but for all I know that might be physically impossible.

Speaking of sucking... now, I'm going to be paranoid that I'll get stuck far from home if this comes up again. I'll do a few more local rides and then go for it with the temperature monitor always on display. Wish me well...

If something new happens I'll definitely post back

 

[atomsplitter]

It would suck in air during cooldown from the overflow tank when the system is depressurizing and goes to vacuum. The air would be drawn in at the top of the rad because the hose that goes to the overflow tank comes off the filler neck just above the relief valve (rad cap seat). The air in the top of the rad would be the first thing purged as the system warms up and pressurizes but would also be initially circulated when the coolant begins to flow as the thermostat opens. The rad cap doesn't lift until enough temperature expands the coolant to exceed about 14 psi, so air any bubbles circulating in the system would collect at the lowest pressure point in the system and that is at the suction eye of the water pump impellor. That's how you get air bound at the pump. Over a few heatup and cooldown cycles the system will self-purge if the overflow tank level is restored because on cooldown the air in the pump migrates back to the highest point in the system leaving the pump full of coolant.