Fixing Acura Cooling System
This bulletin applies to 2017 Acura NSX vehicles. The MIL may be on accompanied by DTC P0128 (cooling system malfunction). The thermostat inner seal may be detached which allows the thermostat to be held open. This causes the coolant temperature to incorrectly increase higher than the expected rate. The fix: replace the thermostat with P/N 19301-58G-A00 and two washers P/N 90471-580-000. Acura recommends long life antifreeze/coolant Type 2, P/N OL999-9011A. You will need the special service tool “rear platform”, P/N 07AAK-T6NA100. This involves about a 4-hour job.
1. Remove all engine covers.
2. Perform the water valve open procedure:
- Turn the vehicle to the READY TO DRIVE mode.
- Select the SPORT+ mode.
- Turn on the A/C and set heater to maximum hot.
- Turn the ignition to the OFF (LOCK) mode.
3. Wait until the engine is cool, then carefully remove the expansion tank cap.
4. Drain engine coolant only from the water pipe underneath the vehicle. After coolant is drained,
reinstall the drain bolts with new washers.
5. Remove the rear bumper cover.
6. Remove the left and right rear inner fender liners.
7. Remove the left and right rear bumper side spacers.
8. Remove the trunk floor mat.
9. Remove the rear bumper absorber.
10. Remove the rear bumper beam.
11. Remove the trunk (at least two people required).
12. Install the rear platform 07AAK-T6A100 to prevent damage to the rear fenders.
13. Remove the thermostat cover.
14. Remove the thermostat and install a new thermostat. Align the tab on the thermostat mounting rubber with the pin on the thermostat.
To prevent damage, apply tape to the underside of the rear fenders and lift both rear fenders
while removing the trunk.
16. When coolant overflows from the breathing plug and breathing bolt, tighten them. Add coolant into the expansion tank to the MAX mark and keep the expansion tank cap open. Turn the vehicle to the READY TO DRIVE mode. Select the SPORT+ mode. Turn on the A/C and set the heater to MAX hot or defrost mode, and let the engine run until it warms up (the radiator fan should come on at least twice).
17. Turn the engine to the OFF (LOCK) mode and wait until the engine is cool.
18. Loosen the breathing plug and breathing bolt, bleed air and retighten.
19. Refill coolant into the expansion tank to the MAX mark and install the expansion tank cap.
20. Turn the ignition to the READY TO DRIVE mode and select the Sport+ mode. Turn on the A/C and set the heater to maximum hot or defrost mode, and let the engine run until it warms up (again, the fan should run at least twice).
21. Hold engine speed at 3000 RPM. After one minute, the engine speed will drop to idling speed. Repeat this step 10 times.
22. Turn the engine to the OFF (LOCK) mode after idling for one minute.
23. Wait until the engine is cool, then carefully remove the expansion tank cap and loosen the
breathing plug and bolt and bleed air. Then tighten the plug and bolt.
24. Refill with Type 2 coolant into the expansion tank to the MAX mark. Install the expansion tank cap.
25. Install all parts in reverse order of removal.
About the Author
Information courtesy of Mitchell 1
Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.
Mike Mavrigian
Motor Age Editor
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.