Track Day in Le Mans

[CB72]

Last week end, I took the car to Le Mans here in France for a "Classic Day" meeting.
Cars ranged from prewar Bugatti's to Porsche 917's!
They put me in the "GT & Young" category with a wide mixture of vehicles as you will see in the video to come.
It was good fun until my water temperature went sky high!
Getting back to the pits the water was boiling.
I had noticed that the coolant had to be topped up before probably due to a very small leak...
To get back home (450 km) one of the teams gave me some magic powder to stop the leak.
It worked fine as I got home without adding any more water.
I know that the NSX is a real pain when it comes to refilling and bleeding the coolant system, specially with my D.A. racing radiator.
I did a quick check today and the engine reaches it's normal operating temperature but strangely the heater does not work probably due to air in the system?
Even more strange the D.A. radiator gets hot only on the right hand side???
When I opened the top drain bolt, drops of cold water came out???
How come?

 

[goldNSX]

Sorry to hear about the incident.

Well, that 'magic (white? ) powder' can act really, really bad in any coolant system and is only recommended as the very last effort to get home. You were able the get home, so maybe it was not really needed. Anyway, if the radiator is warm only on one side I guess that the thermostat doesn't open or is blocked. I usually have this 'warm on one side'-thingy in autumn or near winter, pretty normal, but not during the summer.

When was the thermostat replaced?

The magic powder might have clogged the heater core and it would be a nightmare if it did. Same on the radiator.

I hope your headgaskets survived from the overheating.

 

[CB72]

Sorry to hear about the incident.

Well, that 'magic (white? ) powder' can act really, really bad in any coolant system and is only recommended as the very last effort to get home. You were able the get home, so maybe it was not really needed. Anyway, if the radiator is warm only on one side I guess that the thermostat doesn't open or is blocked. I usually have this 'warm on one side'-thingy in autumn or near winter, pretty normal, but not during the summer.

When was the thermostat replaced?

The magic powder might have clogged the heater core and it would be a nightmare if it did. Same on the radiator.

I hope your headgaskets survived from the overheating.

In theory the "magic powder" stiffens only in presence of air.
The guy that gave it to me has used it on a Lightweight E-Type Jag with no ill effect.
My radiator kept cold on one side maybe because I only ran the engine at idle?
In any case here's the video.
For some reason it's the "uncut" version as it goes on until I reach the Honda stand.
One can hear the water boiling...

https://www.youtube.com/watch?v=nI3o4Ferixo

 

[goldNSX]

In theory the "magic powder" stiffens only in presence of air.
The guy that gave it to me has used it on a Lightweight E-Type Jag with no ill effect.

Therefore, in theory it stiffened here and there in the system.

Horror video: https://www.youtube.com/watch?v=MecSs7YTNn0 FF to 8:20. Sorry, in German. Never ever put a leak stopper in the system. I hope that it's not the problem of your car.

My radiator kept cold on one side maybe because I only ran the engine at idle?

After a cold start?

 

[CB72]

After a cold start?

Yes!

 

[goldNSX]

Yes!

Normal. What about after half an hour?

 

[CB72]

Normal. What about after half an hour?

This afternoon, I bleeded the water cooling system as per the shop manual.
Clearly, there was air in the system ...
I went for a ride and everything seems OK.
The radiator is hot on both sides and the temperature is very stable.
Of course, I couldn't test it at the maximum power level.
I'll monitor closely the coolant level to determine if there are any leaks left?