I have a 1989 i6 and the idle fluctuates after it warms up. Also the coolant temp gauge does not work. What is causing this and how do I fix it? I posted a video of it on youtube to help show the problem.




thanks, you have to listen to hear the engine, but you can see the needle moving

 

sounds like iac but could be a vaccume leak causeing the comp to send a signal to open or close the throtle but as far as the temp prob prob the sending unit is shot if not then the gauge it self

Tom

 

Seldom the gauge, It's the sender, or the wire has become disconnected. If you find the wire, and ground it to the engine, the gauge will sweep all the way to the right. The surge is usually Vac leak related.

 

So your saying the temp gauge is not working due to a loose wire or bad connection?

 

ya,at the sender. or the sender itself is bad.

 

!!!

 

Thanks for the info when I get home Ill do some troubleshooting with sender and wiring.

 

How much do you think a new sender will set me back?

 

They're cheap, probably under $10.

 

WHere is the sender located