crazy temp gauge

[geospider]

stomach in my throat. Temp has been great. suddenly tonight, I looked down and it was bouncing all around; mostly very high: liked PEGGED.
Shut the motor off, but also had to get home and was so closed. Admittedly I thought the bouncing was weird enough to not be too worried. restarted, got closer to home, the needle then stayed mostly pegged. coasted again, turned the key to on, but not start and it was then nicely at 190. stated and it stayed there. Go figure.

so, lesson learned: the gauges can get a bit crazy, but gotta still respect them.

Geo

[GeorgeT]

There are two temp sensors in the head: one for actual temperature and one that pegs the needle when a certain temp is reached. Check the connection to the second one to see if it's grounding out.

[geospider]

yep, know about the 2 and was going to check the connections.
thanks

[kgfiske]

That is a typical symptom of having an air bubble in your coolant passages. When the hot air hits the sender, they go crazy. You may want to check the coolant level and bleed it off.

[geospider]

Loose wire. That front wire can be quite a stretch. prob nudged it when doing other things. Sure is a freaky feeling to see normally good temp #s hit 250.
Now if only my clock would work. Thinking of changing out to an oil pressure gauge.

[maluminse]

That is a typical symptom of having an air bubble in your coolant passages. When the hot air hits the sender, they go crazy. You may want to check the coolant level and bleed it off.

How do you bleed it off? Saw on Jay Lenos Garage his lambo has bleed screw. Same? 124 have one?

Also mine stays at 180 for awhile. Then after a bit of driving it will climb to 220 and stop. Rarely goes higher. Yesterday it did a bit but Im going to ignore it b/c it was once.

From what I can tell thermostat 180, fan at 220. Is this right? 220 annoys me.

[18Fiatsandcounting]

220 oF is a bit on the hot side, but I wouldn't be too alarmed, especially if it was a hot day, you drove up some long hills, drove more aggressively, etc. Generally, IF your overall cooling system is operating up to snuff, the car will run pretty close to what the thermostat spec is, although if you put a really cool thermostat in (170 oF for example), the cooling system may be hard pressed to keep it at that temperature.

Keep in mind your temperature sensor and/or gauge may not be accurate. If you see steam escaping into the coolant expansion tank, definitely too hot.

In answer to your first questions, there are two straightforward ways to totally fill up the cooling system with coolant:
1) Raise the front of the car a foot or so, so that the radiator fill cap is the highest point on the engine and then fill with coolant, or
2) purchase a T-connection and install in the coolant hose from the back of the cylinder head to the connection on the firewall. Fill the radiator with coolant, and also add some coolant through this T connection. These T-connectors are commonly available at just about any store that has a decent automotive section.

-Bryan

[18Fiatsandcounting]

PS: Forgot to mention: If your "full tilt" temperature sensor* on the cylinder head is going bad, it can cause the main temperature sensor to read high, in addition to giving erratic readings up and down to full scale.

*the one that sends the gauge to full scale once it reaches its set point.

-Bryan

[samakijoe]

This is the gadget you need to install. Works every time.

http://www.vickauto.com/newstore/index. ... ts_id=1959

[geospider]

+1 on this. they work great. then no need to get front of the car higher. fill radiator, then finish it off with this.
Vick's and I believe AR also has a tech area that explains the "burping " of these. the process has not failed me yet.

[NSFIAT]

Mine started to jump around (reading both high and low) but I didn’t suspect any actual issues with temperature as the system had been burped,
Etc. I ended up pulling both sensors and cleaning them before reinstalling in the head. The next step was to replace the wiring between the sensors and the gauge in the dash, making sure they followed the factory routing. Problem solved - the readings have never been more steady on the gauge.

[maluminse]

Driving in traffic...

Wasnt driving hard. It toes the red occassionally which is bugging me. I want the burper but I think I have another issue.

Possibly the fan switch is late. It consistently, I believe, comes on at 220. Temp rises to 180, stays a while, then rises to 220 and stays around there.

Saw high performance fans on ricambi. May get one of those and maybe a switch. 220 is too late. Its a new temperature gauge.

[geospider]

Mine was a broken connection at the front sensor on the head.
220 is too high. Mine was around 200 in stop and go at 90+ degrees.
Fan switch is at bottom of radiator, so needs to be burped and make sure T stat opens. run at idle and get an idea at what temp the fan goes on. If you think the gauge is crazy, a bunch of folks get an infrared temp gauge to see what is really happening. I've been lucky with burping; hopefully not pressing that luck.

Geo