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Temp Gauge reads HOT!!!

24K views 10 replies 4 participants last post by  Original1WRX2NV  
#1 ·
Hey Guys,

I have an 02 WRX and I have noticed lately that the OEM Temp Gauge has been going up, little by little. I checked the coolant level and it is good...but, Now it reads "HOT" all the time. In the morning, it goes to hot as soon as I start the cold motor.

I checked the connection behinde the speedo cluster...all is good. Anyone have any suggestions? Is there a sensor I should check?

Thanks in advance

-freddie :)
 
#2 ·
It sounds like it may be the coolant temp. sender/sensor. Especially if it pins out while the engine is still cold. Just verify with you hand that the block is actually cold while it does this.

I had a similar problem with a honda predlude that sat for two months. The temp went past hot after only running a minute or so. After a few heat cycles it read normal.

My EGT gauge on my WRX will act funny if my car sits too long as well. It also goes back to normal after a few cycles. The EGT sensor is a thermocouple, I dont know about the coolant sensor though.

If its under warranty, I would take it in. If not, try the searching the service manual posted on this forum. The sensor probably needs to be replaced. Driving around with a faulty temp sensor (or related problem) is pretty risky though.
 
#3 ·
JRod said:
It sounds like it may be the coolant temp. sender/sensor. Especially if it pins out while the engine is still cold. Just verify with you hand that the block is actually cold while it does this.

I had a similar problem with a honda predlude that sat for two months. The temp went past hot after only running a minute or so. After a few heat cycles it read normal.

My EGT gauge on my WRX will act funny if my car sits too long as well. It also goes back to normal after a few cycles. The EGT sensor is a thermocouple, I dont know about the coolant sensor though.

If its under warranty, I would take it in. If not, try the searching the service manual posted on this forum. The sensor probably needs to be replaced. Driving around with a faulty temp sensor (or related problem) is pretty risky though.
thanks for the reply,

ummm...my car is driven daily, and still there is no change. In the morning when I first start the car...it goes to "H"....if I drive to the store...shop...start the car...if goes to "H". Not all the way into the red, but it goes up there.

Now about a month ago it was normal...in between "C" and "H". Then it just started going higher and higher...again, even in the morning (cold engine) it would continue to go right to the same spot. And now it's into the "H" range.

Anyway, does anyone know where the sensor would be at...so I could check it?

thanks

-freddie
 
#4 ·
Could you clarify why you think it's a sensor issue and not truly an overheating problem? Have you run the car from cold without the rad cap on and verified that there is coolant circulating or?
 
#5 ·
I had the exact same problem around 40K. The fans turned on, all fuses were fine, and the car become cooler at freeway speeds, and would sometimes work just fine. I had a faulty thermostat that was sticking, meaning that it would work on-off intermittenly. This is a easy fix, any mechanic should be able to take care of this for you for under $75.
 
#6 ·
SD_GR said:
Could you clarify why you think it's a sensor issue and not truly an overheating problem? Have you run the car from cold without the rad cap on and verified that there is coolant circulating or?
well, I am not sure if it is a sensor issue...but I dont think it is an overheating issue...Right away in the MORNING when the engine is COLD, it goes straight to "H". If it was an over heating issue it would slowly go up, and would change when traveling faster on the freeway..which it doesnt

Anyway...heres what happened. I had an STi (V7) cluster gauge...the temp was fine, but about 1 month ago, the temp started going up...so I put the OEM cluster gauge back in....it acted the same...so I know it is not the clusters. I double checked the connection with the gauges and they are connected good. I checked the coolant level and it is good.

So, I am thinking it is a sensor...but not sure...I am just looking for suggestions as to what it might be. The easyest thing would be to check the other end of the cluster and see if the wires are connected to the sensor...if such a thing can be done.

-freddie
 
#7 ·
oh, and yes...I did start the motor with the Radiator cap off, and the collant was swishing arround, so I am sure thats ok.

Now, as I am typing this...the car has been on for about 5 min. or so...the fans havnt kicked on....should they?? Now that I think of it..I havnt heard them come on in a while...only a fan sound when the A/C is on...could that be an issue?

-freddie
 
#8 ·
Original1WRX2NV said:
oh, and yes...I did start the motor with the Radiator cap off, and the collant was swishing arround, so I am sure thats ok.

Now, as I am typing this...the car has been on for about 5 min. or so...the fans havnt kicked on....should they?? Now that I think of it..I havnt heard them come on in a while...only a fan sound when the A/C is on...could that be an issue?

-freddie
Fans shoul've come on. Check the fuse box first. Let me know what you find.
 
#9 ·
ej20fan said:
Fans shoul've come on. Check the fuse box first. Let me know what you find.
yup checked them...they all look good.

I remember when I had the motor replaced by a dealership...they had issues with the fans not coming on...they said I messed it up when I modded the car...I never even toutched the fans.

Anyway they re connected the wires somehow and go them to work...

So, I guess I will have to get under there and figure it out. Maybe they didnt do that good of a job.

Ummm, so, does it sound like that could be the cause, and the car really is overheated? Because when I drive...I press in the clutch and coast...the gauge doesnt get cooler, it stays the same. So maybe I have 2 problems going on here...whatcha think? :)

thanks
-freddie
 
#10 ·
Check the thermostat Then, if that was not the problem, keep digging, meaning the pump, radiator, and if all else fails, trade it in and get a new STi.