The thermostat of my 2000 altima reach the stable position and even
the heater is working ok. Now if i step on the gas fast, then the
thermostat needle comes down, fluctuates and even touch "C". If I step
off the gas, then it again comes back to stable state(middle of the
meter).

if i keep running on a stable speed on a highway, or say the speed is
like 45-50, then needle continues staying in the middle( stable state)

Could anyone please help, as to what is the root cause of this..

Thanks,
Sam

the thermostat is not the problem.

You are experiencing a loose connection on the thermo transmitter, that is
what the gauge uses to determine engine temp.

It is located just above the alternator on the aluminum outlet housing the
upper radiator hose is attached to , it has a single wire to it.you will
need to replace that part



<VabsieSam (AT) gmail (DOT) com> wrote

This sounds more like a regulator problem either in the dashboard or the
alternator. Up and down with RPM like you describe doesnt sound like a
flakey thermostat

-SP

VabsieSam (AT) gmail (DOT) com wrote:

So i guess, i need not worry about the ups and downs and just keep on
driving...
or shud i get the repair done!!

-Sam

On Mar 13, 10:20 pm, Speedy Pete <speedythetrash.p... (AT) verizon (DOT) net>
wrote:

What about the system low on coolant?

Speedy Pete wrote:

On Mar 13, 6:57 pm, Vabsie... (AT) gmail (DOT) com wrote:
I have a 2000 Nissan Altima and I had the same problem you have and
changing temperature gauge sending unit took care of this problem ,I
got my part at Pinnacle Nissan at discount price plus shipping ,since
my local Nissan dealer refused to give me a discount ,with shipping
charges I still paid less than local dealer cost.
Good luck
Lado