Temp gauge play and not stays in the middle

[Wiking]

Hi
Today drove to somewhere. Suddenly looked at the temp gauge and saw that it plays a little bit. Checked coolant level + pipes and didn't see any water loose. the play is between 1/2 and 1/4 without any stability or anything. After restart the car it stayed few minutes at 1/2 and then droped to 1/3 for few seconds afterwards moved back to 1/2. Need to mention that I first saw this whlie driving at about 60 mph at open road.
Also, checked the dials instrument for errors but everyting moved as supposted to be.
after coming home, looked at the coolant sensor to see any wires loose but everything seems to be fine.

It's a clio 172FF MK2 2003 K registry with about 50K miles done.

What you suggest to check/repalce/do ?
My suspicion is the coolant sensor or wires of it.

Thank you.

 

[MrMark]

start with the sensor. try cleaning the contacts making sure they make a good connection etc, after that, try and check for cold spots in the radiator, which could suggest a blockage in the system.

 

[Wiking]

Just read a little at dialogys to see if I can get anything. To check the sensor, I need to check it's resistance (will do it tomorrow maybe) and compare to renaults orginal. If it is ok, then something foocked with the dials.
Also, if the temp sensor is not sending the right temp to ecu, than I should see it in car's behavior ? For now, everything seems to be fine besides coolant's needle:dapprove:

Also, as I read the temp sensor send data to 2 places: 1) Ecu 2)dials.

 

[lemonnobby]

Sensor i bet

 

[Wiking]

Bets are good but not at this time

Anybody can write the exact resistance that the coolant sensor should give ?

 

[lemonnobby]

I think furber on here had it on his old car.

 

[A13EX F Trophy No70]

the resistance would change depending on the temperature IIRC ?

might be worth replacing the sensor with a new one cant be to much at least that eliminates one major factor making problem solving easier if that doesnt do it sometimes it's not always finding the solution thats easier but eliminating the posibilities

 

[Wiking]

Ok, drove to work and it got worse. Even if I stand at parking with engine running it plays like crazy frog but only between 1/2 to 1/4 and never upper to the middle.
I'm at the work so anybody can write coolant sensor renault's serial please so I could check if they have it in stock.
thank you

 

[bmh.01]

CTS should read:

• -10c = 9.5kohms
• 25c = 2kohms
• 50c = 810ohms
• 80c = 309ohms
• 100c = 114ohms
• 120c = 87ohms

I'd put money on it being a shagged CTS. They always seem to do what you say, none stable temp gauge.

 

[bmh.01]

7700101451 is the temp sender part number.

 

[Wiking]

Thanks mate,
Just been at stealers and put it to clip. Didn't see any faults but after firing it up the temp started to "run" between 69 to 80 C every few seconds. So, I bought a new coolant sensor and will repalce it tomorrow morning. I anyone want, I'll write a quick guide.
Thank you.

 

[Wiking]

Just wanted to update that I replaced coolant sensor and the problem gone. Everything work fine since then.

 

[en035]

Would you please do a self test of you speedo and post your observations?

 

[Wiking]

what do you mean ?

 

[en035]

hi

press the button on your right stalk whilst turning the ignition on and check the position of the needles.

 

[Wiking]

I did it already before replacing the sensor. the problem was in the sensor itself. Clip showed temp jumps between 69-80 C every few seconds.

 

[Wiking]

So, The problem came back
Just drove few miles and saw that the temp gauge plays between middle to one line and a half underneath it.
The sensor is new and renault genuine, Didn't see any leakage. The car come to work temp as usual.

Now what ? I'm desperate.:banghead:

 

[ditz]

are you sure its a problem?
without being disrespectful you seem to worry about an awful lot that dosn't really need worrying about.

so you say it gets half way up the gauge, stays there for a while them comes down by a line or so then back up after a while?

is it hot where you are? maybe the fan cuts in brings them temp down, cuts out and the temp rises again?

 

[Wiking]

I'm not professional mechanic but I can see when something wrong.
Since I replaced the coolant sensor everything was fine until today. It just started to play like before. There isn't so hot here in IL (about 22 degrees C) so it is not the fan come in and out.I know how the fan work but the temp gauge never moves because of the fan. I really can't understand it. It not affected by my acceleration or whatever just plays without any reason.

 

[ditz]

checked the engine earths?

 

[Wiking]

Ok, Just checked again - It plays just like month ago.

What do you mean engine earths ? where are them ? can you put some pic or how to find them ?

Also, clearly can hear the canister valve ticking (not like before).:S

 

[lemonnobby]

I wouldnt have thought engine earths mate. make sure system is bleed properly. Its a weak thermostat i suspect like i said in my PM.

Canister valve isnt connected to this problem.

 

[Wiking]

Ok, Update:
Took it to dealers garage and after found nothing at CLIP, the mechanic took the coolant sensor's connector and twisted the female connection inside the connector (I'm not sure what exactly but you get the point) and after that everything is fine. He said that by time it become poor connection that makes the gauge to behave like crazy frog.
So for now cloi is fine.
Now I think that replacing the sensor was a mistake after all. Will know for future.
For future members - before replacing the sensor, try to fix the conector first because as I see now, it poor like the TDC one.
French monkeys, would they ever will make decent electric in the car ?