Coolant trouble.

[Honcho]

Are there any other conditions that would create a burst of heat beyound the cooling's system to carry it off?

According to Chris, the failure of the high fan relay/fuse is a prime cause of this here in CO and he has seen it in many NSX's at our track. Basically, the cooling system cannot remove enough heat on the low fan speed quickly enough to prevent a rapid increase in temp that causes a boil over. We will be testing the entire system in a few week and I will report back.

 

[Caustic]

Honcho did say he has an aftermarket radiator. A really nice one at that. The cooling system shouldn't be overworked. I like the suggestion about the full on switch that Chris suggested to Honcho. I also agree with Honcho about the vented hood. From the details provided, the major barf happens towards the end after a day of hard work. The vent could mean a big difference, or at least, just enough.

 

[Honcho]

Well, the verdict is in- blown head gasket.

 

[tof]

Sorry, Honcho. I think I speak for all when I say we had hoped for something way easier and cheaper to fix.

What was the final give-away on the gasket?

 

[latzke]

Sorry to hear the news.

According to Chris, the failure of the high fan relay/fuse is a prime cause of this here in CO and he has seen it in many NSX's at our track. Basically, the cooling system cannot remove enough heat on the low fan speed quickly enough to prevent a rapid increase in temp that causes a boil over.

Another cause of the fan not running is an air pocket around the temp sensor that triggers the fan (sensor doesn't read high enough so doesn't kick on fan).

Seems once there is a cooling problem somewhere things start to snowball quickly (initial problem begets more problems, etc) and things get ugly fast. Lack of warning lights (or a real limp mode - 7000rpm fuel cut at 240F doesn't count) for hight temp or cooling system problems doesn't help either. I'm tempted to get a temp gauge with warning function (spa from SOS) specifically because of this.

I'm not inclined to believe in altitude as cause of cooling issues. To whatever degree altitude impacts the ability to cool, it also impacts the ability to generate heat that would need to be dissipated. (May not apply to a turbo archiving same absolute boost pressure as at lower altitude).

 

[Honcho]

Sorry, Honcho. I think I speak for all when I say we had hoped for something way easier and cheaper to fix.

What was the final give-away on the gasket?

Combustion gases in the coolant bottle. It took Chris less than 30 seconds (2 pumps) for the fluid to turn from blue to yellow. This seriously casts into doubt the tests allegedly performed back in Sept. I am speaking with the owner of that dealer this week.

 

[Stephen@NCAutoUSA]

Combustion gases in the coolant bottle. It took Chris less than 30 seconds (2 pumps) for the fluid to turn from blue to yellow. This seriously casts into doubt the tests allegedly performed back in Sept. I am speaking with the owner of that dealer this week.

Oh man. Yeah I remember doing one of those tests on a previous car. I think I got my kit from napa.

At least you know the issue and can sleep at ease now. Just try and do other maintenance while things are apart. And then drive the car again and be happy!

 

[nsxtasy]

Just try and do other maintenance while things are apart.

Good advice. When my engine was replaced, I made sure they replaced the timing belt, water pump, spark plugs, cooling system hoses, and all the fluids, and adjusted the valves. Even though I was spending a bundle, I knew I wouldn't have to worry about all those things for quite a while.

 

[Mac Attack]

I didn't reply earlier when I saw the results of the "previous tests" performed by your dealer. Based on those, I didn't know what it could be. It sounded like a bad HG, but....

Sorry to hear about that. Especially since you just spent all that money earlier on the major engine service.

Maybe buy that GTR as a new DD while you rebuild the engine yourself? You can do it!

Hopefully you can get some monetary compensation from the dealer. I certainly wouldn't let them touch my car anymore than they have.

Good luck,

Dave