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Overheating - Busted Hose

6 January 2004
Pasadena, CA
This car has never overheated on me in the past 8 years, until this morning. As soon as I saw the temp go up and fumes coming from the engine bay, I pulled over right away. There was a hole in one of the hoses (the lower hose, L shaped), it was squirting what appears to be water and vapor. (see attached pic of hose) Would this cause overheating? Is the part I have circled the high idle valve (16500-PR7-A00)?

Had the car towed to work, during my lunch hour I went and bought a replacement hose (braided), but upon my attempt to install it, one of the lower nipple on the high idle valve broke off, it was badly corroded. GRRR. Frustrating. For a minute, I thought I was going to have to replace the entire manifold, but fortunately, the nipples is connected what I believe is the high idle valve. Part is cheap, about $100, already been ordered. I think I am going to start with that. The fact that it is corroded, is that a symptom of other problems?




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    high idle valve.jpg
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yes it will cause overheat, you are losing water;).

Pic is not clear but from your decription it is the fast idle.

You need to replace ALL 23 coolant hoses NOW.

You should do a leak down BEFORE doing any other work to confirm your overheating did not warp a head.

You need to replace ALL 23 coolant hoses NOW.

You should do a leak down BEFORE doing any other work to confirm your overheating did not warp a head.
You will/should be flushing the coolant when you replace the hoses. Wherever you keep track of your services, note this, since this resets the interval for coolant replacement (normally every 2 years or 30K miles, whichever comes first).

And, in the future, it's a good idea to replace your cooling system hoses every once in a while. Doing so whenever the timing belt and water pump are replaced makes for a suitably long interval, and saves labor and coolant too.
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The NSX has 199,786K miles and she is still a beauty, very reliable. The is the only time I have had to get a tow for mechanical failure, and it seems to be something really simple. For now, I am just going to replace the fast idle valve and the hose. In Sept. going to go in for another TB/Water Pump job, I will replace all the hoses at that time. Anything else worth replacing?

My clutch only has 30K miles but the throw-out bearing is busted (it was replaced also 30K ago), noise is annoying with the car is idling. It is my understanding, even if I just want to change bearing, it involved a lot of labor, is that correct?


Well, I replaced the high idle valve, quick fix, 3 bolts and the part was $120. Started running the car, no leaks, hoses are holding up, but the car started overheating again. I did a little bit of research, it may be air in the system that is not allowing the coolant to run, air may have entered when I removed the high idle valve.....ugh...what sucks is the shop I take it to is 70 miles away and a logistical nightmare (getting a ride back). Can it be air in the system? Should I try bleeding it? I'm not too handy, if I take it to a local shop for a coolant flush, does that include a bleed?

Car has 199,768 miles, it is time for another TB/Water Pump job. Aside from the TB, Water Pump, Head Gasket and Valve Adjustment, is there any thing else that should be done? Also going to change out all of the 23 hoses suggested. I was thinking about selling the car, but if I'm doing this, I figure I would hold on to it for another 100k miles.

When you say: "I am not too handy" it tells me: take it somewhere experienced.

Frankly the car needs to be evaluated by an experienced tech. Put it on a flatbed and do it right, once. First Step: LEAK DOWN Then an experienced tech can bleed it properly and re-evaluate.

I would also change the thermostat during this process. It may be fine, but with the overheating that took place and all the work that needs to be done (starting with the leakdown test :biggrin:), its a cheap item.