USF MZR Cooling

[racpercival]

Trying to troubleshoot some heating issues and need to know a few things from this brain trust!!!

Getting hot spikes of the water temperature, meaning that I see 170, 200, 195, 230, etc and it falls and rises just as fast as it appears.

Curious about how these functions within the cooling system:

What is the black cylinder that sits between the radiator tower and the vent tube to the air. Why did they not go directly from the tower to a catch tank? What is the benefit?

The second silver bung goes directly to the top of the right radiator. What does that do? Not sure if there is a temperature sensor on the radiator side. I have to check.

All ideas welcome!!!

Thanks!

[Jayeff]

if you are running a thermostat i'd replace it. the lines you show pictures of are bleed lines to bleed air out of the system. make sure they are tight. And of course i'm assuming the coolant is high enough in the tank.

[Lotus7]

Trying to troubleshoot some heating issues and need to know a few things from this brain trust!!!

Getting hot spikes of the water temperature, meaning that I see 170, 200, 195, 230, etc and it falls and rises just as fast as it appears.

Are you saying that your water temp readout changes/fluctuates by as much as 60 degrees almost instantaneously?

If so, you either have a failing sensor, a loom fault, or you are not reading solid water temperature (i.e. air pockets, but even those wouldn't necessarily change instantly, but would over a few seconds). Water cannot change temp that fast on its own.

[mikey]

I had same question as Ian. How fast are these fluctuations occurring? If within seconds or instantaneously jump then it’s an electrical issue. Either your positive reference voltage or ground is being interrupted, shorted, or crossover to some other resistance.

[racpercival]

Thanks guys. So I filled (and might even have overfilled the radiator) to make sure that I had enough water/water wetter. As a result, it was definitely filled before driving. The spiking/fluctuation is definitely there, but maybe not as rapid as I originally described, and would suggest it’s not just water temperatures, as Lotus mentioned. The fluctuations suggest that is a reading water (lower) and vapor (higher) temperatures. So I’m thinking there must be air bubbles in the system. That’s what it feels like.

After the car cooled down and sat for a few days, the water is now very low under the radiator cap, and I also noticed a buildup of water on the side pod with the black cylinder, but could not determine where it came from, as everything else (hoses, radiator) was bone dry.

I’ll check the sensor, but the fact that the water is so low after driving may suggest a leak somewhere?

Why would one of the bleed lines bleed right back to the radiator?

That black cylinder (inline with the larger black bleed hose) is Mishimoto but I don’t know what it does.

[Bob Wright]

One thing I have discovered is the bleed line can get plugged and you end up with potential air bubbles in the system. Blow it out with air and make sure its open all the way into the swirl pot. Rapid random spiking of temperature is usually a sensor. If its in the wiring and you are using a T2 ECU, note the oil temp, oil pressure and water temp circuits are all interconnected and operate at 5v and all will be affected. Air bubbles tend to to show the water temp spiking to 230+ then dropping back down to something reasonable (reading the air bubble, not water) while your motor cooks itself to death.

I have never seen the black thing- how is it connected to the cooling system? I suspect it is a oil intercooler based on a google search.

[J Leonard]

I think that Mishimoto thing is a catch tank. Line to it is the vent line if the rad cap vents. Like said, make sure you blow out the small vent line at top of rad that goes to the tank with the rad cap.

[racpercival]

Thanks to you both. I hope that the motor was not damaged. It still seemed to be pulling strong and I pulled it in and shut it off after a few minutes of observing this.

I will remove that black reservoir, blow out, or even replace both vent lines from the radiator top and install a regular catch tank like in this photo. I assume that is what most guys have? I’ll also replace the radiator cap.

[J Leonard]

Maybe just a Labatts or Red Bull can.

[racpercival]

Stella - would that work?

[Spengo]

Maybe just a Labatts or Red Bull can.

Someone's been spying on my speed secrets.