# Temperatue Gauge Fluctuating-



## scoobydoo55 (May 21, 2006)

2001 Nissan Altima GXE
49000 miles


Hi all 
A few months ago i noticed the temperature gauge fluctuating on my car,sometimes it drops to 0 ( the lowest number on the scale). i know this is incorrect because i have been running the car for long periods and the car should be hot. I recently opened the cap on the radiator and noticed some type of a brownish looking paste at the top of the radiator, also i'm not sure but if u leave the radiator open and let the car run isn't the level supposed to go down when the thermostat opens, my level doesn't seem to drop so i can add fluid to it. one more thing , my overflow tank has a hole at the top , fluid doesn't leak out of it but could this be causing any of the problems . i just dont wanna drive the car while it is extremely hot and know know it , i'm the type that like to make sure car is Ok, 
Thnaking you guys in advance for all of your help


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## LONDONDERRY (May 19, 2004)

scoobydoo55 said:


> 2001 Nissan Altima GXE
> 49000 miles
> 
> 
> ...



Check the temp sensor its probably loose.


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## scoobydoo55 (May 21, 2006)

where is the temp sensor, can it be replaced and is it easily replaced and what about the open overflow tank is this a problem


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## Vandy-1 (Apr 14, 2006)

scoobydoo55 said:


> 2001 Nissan Altima GXE
> 49000 miles
> 
> 
> ...



The brownish paste you saw in the rad could be a stop leak sealer additive such as 
bars leak that someone put in there, if not your system likely needs a flushing badly.
Your coolant level is not dropping because the system is full.
If you need to add coolant always add it to the overflow tank, the system will suck what
it needs from the overflow tank or burp some back into the tank if necessary.
The hole at the top of the overflow tank will have no effect on your problem.
Your coolant sensor and sender are next to each other on the pasenger rear side of motor.
but first check to see that a fuse is not blown.
The Haynes manual for your car {#72015} around $15 at auto stores has details on how to diagnose and replace if necessary these parts, as well as photos of their location on pages 3-6,6-6,6-7.


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## scoobydoo55 (May 21, 2006)

hey thanx a lot, but the radiator is about a year old, i put it in there myself so i know it isn't stop leak or anything like that


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## Darktide (Jul 29, 2004)

Scooby, someone else just had a silmilar problem. Check your serp. belt tension. If its not adjusted properly then your water pump will spin when it gets tight and then stop when the belt slacks off. 

As for leaving the radiator cap off while it runs until it gets warm enough. that only normally happens if there was air in the system. You do that after you've had to change any part in the cooling system. Even though you changed your radiator the gunk that built up inside your block won't leave and just changing fluid won't take care of it. You should probably get your coolant system flushed though I don't believe it has anything to do with your problem.

Just remember to check the belt tension and the sensor, the blown fuse would just have killed the gauge altogether. Good luck with it.

Darktide


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## scoobydoo55 (May 21, 2006)

hey u might be right , because my belt has been squealing so i'll get the belt changed as well


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