Water temperature: Too cool?

[edsdad]

'91 NSX, 28K mi. New OEM hoses within past 2K miles. Running 3500-4000 RPM in 5th gear for several hours. Ambient temperature mid-high 30's. Heater on. Needle on water temp gauge did not climb above bottom (blue) hash mark even when ascending Grapevine. Needle climbed to second hash mark upon exiting freeway and driving @ 1 mile to/from filling station, but returned and remained below bottom mark when resumed cruising. Previous highest reading was third hash mark while idling in traffic with A/C set to MAX on hot summer day. Cause for concern?

 

[nis350]

'91 NSX, 28K mi. New OEM hoses within past 2K miles. Running 3500-4000 RPM in 5th gear for several hours. Ambient temperature mid-high 30's. Heater on. Needle on water temp gauge did not climb above bottom (blue) hash mark even when ascending Grapevine. Needle climbed to second hash mark upon exiting freeway and driving @ 1 mile to/from filling station, but returned and remained below bottom mark when resumed cruising. Previous highest reading was third hash mark while idling in traffic with A/C set to MAX on hot summer day. Cause for concern?

probably a stuck open thermostat...

 

[DRIFTER]

V-tec Wont engage ether if the car is not wormed up to a cretin temp.Check the thermostat (I had this problem)If I’m not mistaken the red line will kick in early to.