So my car has been overheating the past couple days. The needle has been bouncing between normal and very high. I checked out the coolant level and it seemed fine but I added some more and still have the same issue. I'm thinking the waterpump might be going but the car still has some decent heat coming from the heaters. Any other idea's of what may be causing it?

My drive is mostly suburban and highway driving.

 

could be your thermostat im pretty sure i spelled that wrong but it triggers your cooling system when your engine reaches running temps.
Or radiator fans.
amature advise by the way im no mech but i understand the basics.

 

99.9% of the time the thermostat is always good. It does smell like a slight burning under the hood, so i know for a fact that is not it.

 

Have you flushed and replaced the coolant lately? Its possible an air bubble is in your coolant system causing your car to overheat.

 

For me it was the fans,they were replaced by the dealer on warranty.

 

Photo of the temperature gage. Thanks.

 

Don't know how many miles are on your car. Yes it could be a sticking thermostat. Are your fans turning on? They are controlled by a temp sensor that kick on the fans when the coolant reaches a certain temp. It could also be your radiator is restricted from buildup not allowing the coolant to flow.

 

I had the exact same problem and thought for a fact that it wasn't the thermostat, but in the end, it was the only problem.

1. Are your fans turning on and running properly?
2. Check the 2 radiator tubes, (the big thick black ones), if the top one is hot and the bottom is cold, you aren't getting any coolant flow, which is what my problem was. In that case, it's most likely the thermostat
3. When it begins to overheat, and you turn the heat on full blast, does the temp. go down?

I'm gunna have to say bad thermostat
Try not to drive it till you get it replaced

 

+1...exactly what I was going to say Check the upper and lower radiator hoses to eliminate the thermostat. If your coolant system flows freely and your fans work, it could be the that water pump has gone bad.

 

wouldnt the water pump leak if it went out? Ive had two cars with water pump problems and they both leaked and thats how i found out they were gone.

 

could be pent up sexual frustration.

 

very helpful and useful info...

 

sorry to have confused you, you see, it's an 'inside joke'.

welcome to my350z.

 

Don't mean to threadjack but my car is doing the same thing right now. Just noticed it today b/c my A/c wouldn't blow cold. I popped the hood and the coolant inside the reservoir was literally boiling. The fans won't turn so is it possibly some kind of sensor problem with the fans not turning? Or is it most likely thermostat? I have 03 with 65k.

 

wow... It seems like a lot of people having the same problem..
I got 04 touring (70k miles) and this is what happened to mine:
first - I was driving in the city for a little while. Then, stopped at the gas station. Turned the car off, turned back on again - a/c stop blowing cold air (that day was really hot). Drove the car for 10-15 min., then turned it off and on again - a/c start working normally.
That day I didn't pay attention to the temperature gauge. And after that day I didn't have long trips anywhere - only to work and back home (5 min each way). In a couple of weeks it was my day off and I decided drive somewhere far. On the way back home I noticed that the temperature arrow is above normal position (usually it is a little less than a half way), and that day it was up to 3/4 - which still considers as a normal temperature, but I never had seen arrow this high before. All the way home I was checking the temperature gauge and the arrow was always between 1/2 and 3/4.. I park my car at home, turn it off and on again - and right when I just turned it on temperature went all the way up to almost red zone and in a couple of seconds went down to a position little above 1/2 again... So I checked the fluid and fans - everything was normal. Both of fans worked fine, fluid level was ok.
For about a week after that I was checking my temperature gauge and this is what I found out. If I'm not accelerating hard through all of the gears (keeping rpm under 3500) - everything works normal. And only if I drive the car for a little while and after that, go beyond 4000 - temperature starts rising and never coming back to the normal position until the engine gets completely cold. The same time a/c starts blowing hot air (after turning the car off and back on) - i.e. I'm driving - stopped somewhere to get a bottle of water - turn the car on - a/c not working - driving 1-5 min. - turn the car off and back on - a/c working........
One day after driving for about 30 min. I turned it on - it started with poor idling and threw check engine light on. I scanned the codes - scan tool showed 6 codes, 2 times P1148/P1168 and P1031/P1051 with MIL ON.
The codes are:
P1031/P1051 - air/fuel ratio sensor meter
P1148/P1168 - Closed loop, bank 1/2
So I went to research what does it mean and found this:
IF YOU CONFIRM: A MIL "ON" with the following DTC(s) stored: · P1031 / P1051 (A/F Sensor Heater), and/or · P1148 / P1168 (A/F Sensor Closed Loop Control), ACTIONS: Step A: Confirm this bulletin applies: · Check the Current ECM Part Number. ·Compare your Current ECM Part Number to Chart A. If that part number does not match one in Chart A, this bulletin does not apply. Go back to ASIST for further diagnostic and repair information. Step B: Reprogram the ECM. Step C: Perform A/F Sensor test to confirm proper air fuel operation. See this bulletin for further detail.
Of course, I have no idea what is all that means...
I erase the codes and continued driving my car - again from home to work and back. For about a week - nothing unusual.
Another day off - and here we come again. While driving, temperature started increasing again, a/c not working, and then I'm starting the car after a little drive and it starts idling poor again, and becoming to idling normally only after around 15 sec. of pushing the gas pedal........
Any guesses??? WTF is going on???
Check engine never went back on again yet, but I'm afraid it will - sooner or later.
Already have a new thermostat in the trunk but not sure if this causes the problem...
I have this car for about 9 months now - never had any problems with it.

 

If the fans are not turning on then the fan motors might be bad. Try to put 12v to the motor straight from the battery and see if it works.

 

are your fans going on? if not check your fan fuse relay.

 

Due to the nature of water pumps, they leak when they're about to fail. Its a built in weep hole when the diaphram fails.
Its not the water pump if its not leaking.

 

Replace temp sending unit to the fans.