What Is The Cooling Hose Recall?

* THERE IS A RECALL ON THIS ISSUE *

See [TSB_92-030|Technical Service Bulletin (TSB) #92-030, "NSX Cooling System"]

NOTE: If you have an older NSX it is probably a really good idea to replace these hoses whether the recall work was done or not. Rubber hoses deteriorate with time. Many owners of older NSXs with original cooling hoses have had a hose burst.

The 1991 US NSX’s had a product update up to and including JH4NA1***MT002406 for 3 coolant hoses (up to and including JH4NA1XXXMT800272 for 1991 Canadian NSXs). The hose update was only on 3 curved hoses close to the engine: the two at the engine and the curved hose in the tunnel. There was an additional part of that update that included the water pump on selected engines. The dealer was supposed to make a small punch mark over the "J" on the Vehicle Identification Number on the rear wall of the engine compartment when this recall work was completed.

[BCH] My car experienced this failure. I downshifted and got on the throttle and suddenly there was coolant all over my rear hatch glass (good thing I removed my engine cover, otherwise I may not have noticed it in time).

Here is the list of affected VIN’s for the Coolant System Recall.

Cars Known To Have Had This Recall Work Done

   

      

        
 Car VIN 
        
 Date Completed 
        
 Miles Completed 
      
      

        
 JH4NA1154MT000444 
        
 8-??-97 
        
 ? 
      
      

        
 JH4NA1155MT000470 
        
 12-9-92 
        
 9,579 
      
      

        
 JH4NA1156MT000705 
        
 3-22-94 
        
 30,391 
      
      

        
 JH4NA1157MT000962 
        
 8-29-94 
        
 20691 
      
      

        
 JH4NA1156MT001062 
        
 2-28-95 
        
 22,070 
      
      

        
 JH4NA1150MT001218  
        
 1-6-93 
        
 8,531 
      
      

        
 JH4NA115XMT001274 
        
 4-17-93 
        
 16,731 
      
      

        
 JH4NA1157MT001278 
        
 3-2-93 
        
 4,972 
      
      

        
 JH4NA1151MT001664 
        
 9-16-93 
        
 3,878 
      
      

        
 JH4NA1155MT001747  
        
 9-10-93 
        
 6,200 
      
      

        
 JH4NA1154MT001786 
        
 3-1-95 
        
 11,127 
      
      

        
 JH4NA1153MT002055 
        
 2-8-93 
        
 16,046 
      
    

Coolant Reservoir Leaking?

[A/H] Check the seal on the cap. Many times coolant will leak out of the cap and collect at the horizontal seam making it look like it is leaking there.

[BC – 98/11/12] I noticed today that my coolant bottle hisses after long drives, which seems like new behavior, so perhaps it is just losing small amounts of coolant vapor over time, which wouldn’t leave much residue.Consider boiling half a gallon of water in an open pot on the stove, it is completely vaporized within hours – even at lower temperatures a small leak could release the same amount of vapor in three months. On closer inspection, the bottle also has many tiny fractures in addition to a couple of large cracks. So I guess I’ll take this as a sign to buy a new bottle (about 80$) and paint it appropriately. I think I recall someone else reporting coolant bottle cracks in a 91.

[AW – 98/11/12] I had one develop a crack near or in the seam and thus a slow leak, but my engine cover’s always been on, so UV probably isn’t explanation. Lots of expansion and contraction of a semi-flexible joint that’s under stress is probably a better explanation, although UV might accelerate it.

[RWI – 98/10/14] If you track your car, make sure you take care of this problem before you head out to the tracks. Or else, your car will over heat after 2-3 fast laps. If you don’t keep an eye on your temp gauge, you could end up with a warped head. Your $100 problem just turned into $$$$$ headache.

[JWI – 99/11/7] I replaced the cap, which helped, but I can now see that some coolant is still leaking from that rear (or is it front?) hose area (in any case on the top, near the cap!). I haven’t tried this yet, but I have been thinking about replacing the hose or somehow reseating it.

[BC – 99/11/7] The older the coolant bottle gets, the more prone it is to being depressurized by heat cycle cracks, in which case it will steadily lose coolant in the vapor state. An original coolant bottle on a 91 is an engine overheat waiting for an inconvenient time and place to happen. It would be a good idea to get a new one, unless you have an obsessive compulsive disorder that makes you check your coolant level every week… or are keen on developing such an affliction. It ‘s hard enough dealing with oil level and tire pressure fixations without therapy.

Troubleshooting