Overheating

[adnankmehmood]

Hi guys, I am new to the board. Just wanted to know if anyone has had overheating issues with their NSX while tracking it and what you might have done to correct that. I ran the big track at Willow last Sunday and my car was running hot. If I didn't back off it would have run itsself all the way in to the red.

My NSX is a 1991 with 160,000 miles on it, it is now my dedicated track car. Everything runs great on it except for the overheating issue.

Your help is truely appreciated.

 

[VBNSX]

are you bone stock? What mods do u have?

x

 

[adnankmehmood]

I upgraded to steel braided brake lines, sloted rotors and performance brake pads. I also changed the transmission to a the 6 speed transmission and have the comptech clutch in there. Other than that the car is pretty much stock.

 

[Hrant]

Overheating by some NSXs at some tracks seems to be normal here in California when ambient temp is above 90F. If you do a search you will find a few posts.

A few of us have the same problem at Thunderhill, and so far we have not been able to find a totally satisfactory solution. Try replacing the coolant with water and water wetter and see if that helps as a first step.

 

[VBNSX]

Courtesy of Chris @ SoS:

Start car - in front radiator, squeeze hose, make sure the hose pressure is stiff s.t. you have a hard time squeezing it

drive car - come back, make sure that your radiator fan goes through both stages (2 stage fan).. takes a bit but it does go through both stages...

when was the last time you flushed the system. May have air bubbles?

x

p.s.- incredible timing on the response..

 

[mystican]

Bleed, Bleed, Bleed air from the system...follow the manual and talk to others who have done this procedure...invariably I have found not just in the NSX, but in other race/track cars...that tiny air bubbles are the culprit...

Try replacing the Radiator cap with a new one...

Try the distilled water and "water wetter" as already suggested...

Make sure the OEM ducting is present in front of the radiator...

Other than that...take it to someone who is familiar with the NSX and check for blown Head Gasket...

 

[RP-Motorsports]

We battled this on a track car of ours for 2 years. We did EVERYTHING. (diff cap, radiator, burping, h2o wetter, fans wired on etc etc) It would ONLY overheat after about 10 miles of full track use. It would never overheat on the street.

After 2 years of diagnosing, guess what it ended up being?????????????????????????????????????????????????????????????????????

Pin hole failure in the head gasket.
(still drives 100% ok on the street)

Have your tech do the rubber glove test on your coolant bottle.

Rule a head gasket out first, and work backwards from there.

We had about 85k on the motor, you have almost double that. I am guessing early gasket failure.

 

[adnankmehmood]

Thank you very much guys. I really appreciate your help. Hope to do a track day with you this month.

 

[Hrant]

After 2 years of diagnosing, guess what it ended up being?????????????????????????????????????????????????????????????????????

Pin hole failure in the head gasket.
(still drives 100% ok on the street).

Curious, how did you diagnose this? TIA.

 

[RP-Motorsports]

John Vassos @ Acura of Brookfield has been working with us on the overheating for 2 years. We did the diagnosis backwards as 99% of us would do. We did the free and easy things first, and worked our way through 24 months of BS until the end cause. People should start with the head gasket first, and then if that check out ok, then do the simple fixes next.

It would not add air to the system under street use, thus we assumed that the head gasket was not it. At the track, 3 laps in, and needle pegged to the red. We assumed a faulty cap, tank, pump, radiator, oil temps too high causing it, plugged lines, fans not on, etc etc etc

John was finally going to do two things check the fluid after a flush and heat cycle for exhaust gasses (which were so minimal, that never any color coming out of the exhaust even at the track) but prior to that, he used a n-dex rubber glove somewhere in the system (was not there when he did this) where it should not be pressurized from heat (cold engine) and away from the pump pressure. (you will have to ask Steve [NSX30 on Prime] or John himself. He saw a difference in how the glove inflated compared to a "good" test mule. Therefore he concluded that there is a very small failure in the gasket or seat, causing air into the system then causing overheating from the hot gas, and from bubbles hindering flow.

 

[Hrant]

Thanks.

How well did the fix work? Do you still get the water temp needle above the middle bar? If so how far?