For the past couple of days my girl's 95 Maxima has been acting possessed the temp gauge it goes near hot, back down to the middle, near hot, back down to the middle sometimes and it only does it like every 20 to 40 days or so.

Do I need to replace the Thermostat?

thanks for any help

 

maybe flush out your system and see if that helps, if it still does check your thermostat. The funny thing is when the thermostat is closed it should heat up, then if your thermostat is open your engine does not warm up. except for hot days. I live in Chicago and when it was cold out the temp did not move above the C, cause it was stuck open. Someone can correct me if I'm wrong.

 

ok i will try that this weekend and see what happens.

 

Mine dips down to C and back to the middle, only in the upper RPMs, I think I have an electrical problem though.

 

Modern thermostats are usually waxstats. These fail in the 'open' condition. So I rather doubt it is the stat, although it's possible. I hate to say this but it just might be the water pump starting to fail. However it could also be a partially blocked rad, so start by flushing the system properly and refilling with the correct coolant mix. If that doesn't help, change the stat. If still bad, before going for the pump, connect a separate temp gauge, and see if that confirms the problem; because it could also be the gauge itself going bad.

 

Probably a bad temp gauge happened to a friends max, temp gauge was junk. Thermostat is easy to get at, follow radiator hose to engine on passenger side near the alternator, it's right there just take off hose from engine. If it is in working order, the temp gauge is probably the culprit.

 

the is a few problems. each person may have a differnt one of these, but im sure these are the problems.

radiator - solution www.radiatorbarn.com
thermostat - autozone
waterpump - www.rockauto.com
fans not spinning or not spinning at the rated speed - www.ebay.com (or above sites/locations).
temp gauge - autozone ?

there may be one or two more options but those are the main.

find out if its overheating first. cause if it is, then you dont need a temp gauge.
then check the radiator - if its got a birds nest or debre in it, then it needs to be cleaned out or replaced. the nissan maxima manual (the big book - mabe the small one) has a guide to test your current thermostat to see if it still works - most would just replace it because its cheap and our 4th gens are old.

i need a new radiator and thermostat myself.

 

many people on here have confirmed that 95's have faulty gauges...i'd look for one of those from someone on the org for about $25 and try that first...

the thermostat from the dealer is like $15 so you might as well change and flush your coolant while you're at it if you haven't in a while.

 

Has anyone said it could be your fans? Are they in working order? If not at idle or slow speeds you could run hot and then cool down when at cruising speed. Just a suggestion, but it's probaly rad or thermo.

 

thanks for the reply's ended up taking it in and having the water pump, hoses, and thermostat replaced just to be on the safe side. I'll be doing my own water pump and thermostat on my 93.

 

My water pump seal went bad, and it let in an air bubble, that caused the temp to rise at idle and fall to normal at high rpm's. It stopped once I got a new pump.

For your sake I hope thats not it.