Hey all,

My coolant temp gauge has been acting up lately. When it sits overnight and I start in the morning it's at the far left and won't move until the car is driven for 15 mins or so then it wakes up and gives a good reading. Sometimes after it wakes up it'll fall back asleep and drop back to the far left (160/0). Put in a new sensor last weekend, bled coolant etc and it still does the same thing? WTF?

Today I started it up, it worked immediately and moved up to nearly 210, then driving on the hway it dies and goes back dead to 160. Stopped for gas, started the car back up and it awakes at 210??

 

When your running your car and you shut it off it always heats up slightly then when you start it it goes back down.

Now that iv said that and im sure that is not your problem, I have no idea wtf is up with your gauge sorry.

 

could be a bad gauge or wirirng

 

I know how you feel my temp gauge has been acting up also. It will jump up and down until it gets to like 160 or 180 (I forget what the first mark is) and then it reads just fine. I also have that low coolant light problem that people tend to have with these cars, but i don't think they could be related. I just thought it was a sender but maybe we can get some more ideas here.
P.S. sorry i don't have a answer for you

 

What do you mean it drops dead to 160? My car takes the same amount of time to heat up, thats normal. Then as I drive the temp will raise usually all the way up to 225. It goes up and down in stop and go traffic but once im moving over 50 it usually sits right at 160 or just under/over. Only takes about 10 seconds to drop the temp from 210 to 160 when your moving quickly.

 

dead to 160 means 160 is the lowest number on my gauge (all the way to the left) it just falls back there from time to time.

someone mentioned a faulty gauge? is that replaceable? looks like it's all one piece on the instrument cluster? wiring? dunno...nothing in that part of the car was ever touched...seems unlikely that all of sudden a wire would go out??

 

My temp gauge does the same thing. I replaced the sender about a year ago and it worked fine for awhile then it started acting up again. I can fiddle with it and it will work for a while and then stop again. Must be a loose connection or something. I dont really know. Also, my low coolant light stays on but that is not related. As for the gauge though, it beats the hell outta me as to why they are so sh*tty.

 

Check the connector on the end of the wire going to the sending unit. If it's been unplugged and plugged back in quite a few times the contacts on the inside of the connector can get bent out and will stop making good contact with the pins of the sending unit. Pull off the connector, bend the pins in slightly and try it then. It should clear up.

 

Very easy to damage the wire/connector to the temp sensor. The sensor is located between spark plug 2 and 4 on the driver's side head. The wire/connector gets abused by both your exhaust heat and your hands everytime you change plugs.

 

Are you sure you bleed the system completely? I had similiar issues but it was because I had air pockets that would cause it to jump around. When you started it and it jumped up to 210 was that a cold start or hot start?

 

yeah uuhh that wire isn't that sensitive... it constantly rubs on my header and never had a problem...

it sounds like you have air in your system... air pockets are extremely hot..

 

the re start was a hot start. the car was driven for 45 mins and it sat at zero. stopped, filled up gas, re start it woke up and went to 210. i'm pretty sure i bled it completely. spent a good 20-30 mins...ran clear for at least a minute? is this a probable cause? should i re-bleed?

 

i'll try that too, but plugs have only been changed once since factory, and that was 5 yrs/10,000 miles ago. it only started doing this last few months and no one has touched anything in that part of the car.

 

Ehhh...if no one has touched them they might not be it then...can't hurt to look though. I would bleed the system again anyway like others mentioned.

 

thanks for the replies guys. i'll try the suggestions mentioned.