my car has been overheating. my coolant is full in both the radiator and the the little plastic thing. i dont know whats wrong. can anyone help me out?

 

Has it been stalling and smoking, or the needle just a little above normal?

 

sound like your thermostat.

 

1 - Use an obdII tool or consult to verify engine temperature reading is above normal (160-220f) (testing for bad gauge here.) Make sure thermostat is opening and closing properly via same scan tool.
2 - No reading or wacky #'s indicates bad coolant temp sensor but this would usually turn on SES light.

OK, so it's actually overheating. Now what..

1 - Pressure test cooling system to check for leaks
2 - Verify that both electric cooling fans are coming on, with and without A/C on.

Fans coming on, no leaks, still overheating..

1 - Make sure air flow to rad is not restricted (bent coils, clogged radiator)
2 - Check water pump drive pulley and belt.

Other possibilities: cracked block, head, warped head or block surface, head gasket blown (water in coolant and/or thick white smoke)

That should get you started...

 

Damn! No need to scare him. Its probably just the thermostat. They are usually pretty easy to change, but I have never dont it on this car.

If that doesn't work, try a flush and fill on radiator and engine (coolant passages). You should probably do this any way.

 

that sounds like a lot of stuff to do. the ses light did come on. but my car has been overheating for about 2 weeks and teh ses just came on about 3 days ago. i dunno if its just a coincidence. my car doesnt stall or anything, maybe because i dont drive it enough to get that hot. i havent drove it enough to really get past the line on hot on the temp gauge.

 

You cars not old enough to have the radiator plugged but I bet you've never changed the anti-freeze in it either. I've only seen 1 t-stat that was bad in all the years that I've worked on cars so I'd first look to make sure that your fan is kicking on like Paralyze said then to the pressure test. I'm not sure about Maxima's but most cars heater cores don't like anything above 5-7psi.

1) Check fan
2) Pressure test system (check inside passenger side footwell for coolent)
3) Test or replace radiator cap
4) Water pump singing or leaking at all?
5) Exhust smell funny(sweet?)
6) White smoke?

If your loosing coolent and there are no leaks then it either a head gasket or block.

If you not leaking coolent but still running hot it's either a water pump, fan, temp senser, blocked heater core, or a cardboard sign your friend put in front of your radiator that says "I'm gay".

 

If there are no obvious signs of overheating (white smoke, coolant smell, leaks, a/c quits blowing cold all of a sudden) that's why I think he should verify first that the temp. gauge is reading accurately and that the sending unit or sensor is not defective.

 

True. Especially if he got an SES.

 

While we are talking about radiators and stuff, does anyone know where I can get a cooler thermostat for a 2000 maxima?? I would like my car to run a little cooler, the needle stays at normal but I think a little cooler thermostat would make it run a little better.

 

my ac does quit blowing cold air. but i ahvent really been turnin it on lately, even though its been really hot, cuz im scared the car might really overheat.

 

sounds like you just have air in there or your thermostat is staying shut.

To check for air, turn on the heater, if it blows cold then you have massive air in the system.

If your radiator is not getting hot then you probably have a stuck thermostat. It is a cheap repair if you can do it yourself.

 

It would actually make it run worse. Unless you were supercharged or turbo charged where you are creating extra heat that the car was not designed for, you would be throwing the optimal working temp too low.

 

the other day i put in some coolant htinkin i didnt have enough. but it didnt really help and it like just like floated about the old coolant and u can see it. so i figured maybe the water just isnt rotating or soemthin.

 

thats wrong.
i have a 2000 and was overheating. flushed radiator, didnt help. changed the thermostat, didnt help. went to dealership and had pressure flush done, didnt help.
ended up the radiator was completely plugged up. so the thermostat was opening but coolant couldnt go through the radiator so it was all just sitting in the engine block,filling up the resevoir, and boiling over. im pretty sure the previous owner never did a flush.
so i had to buy a new radiator. found one online for $170 (dealership wanted over $300. now i do a flush once a year to be on the safe side.
dealership can do compression tests to see where the clog is. any radiator shop shuld be able too as well. i just went to the dealership cause i know the guys there.
good luckl

 

thats wrong.
i have a 2000 and was overheating.

Then the PO was dumping that stop leak **** in it for three years untill he sold it. My current Jeep I've had three years and I've never flushed it out. My gf's old car I never flushed it and it always ran cool.

If a car's radiator's gets clogged after three years someone is screwing with it.