I just bought a 1994 Town Car Sig Series with 116k. My problem: The Temp reading on the dash fluctuates by 2 bars but stays in the normal range.
There is plenty of antifreeze.
Question.

1) Will this trigger a check engine light if out of acceptable range?
2) Should I replace the thermastat or the sending units?

Anyone experience this type of problem?

I've only seen it when there's air caught in the system. I really wouldn't worry about it if its only fluctuating a little. I don't think the dummy light triggers on cars with the gauge but I may be wrong. It won't throw a CE light though.

I've only seen it when there's air caught in the system. I really wouldn't worry about it if its only fluctuating a little. I don't think the dummy light triggers on cars with the gauge but I may be wrong. It won't throw a CE light though.
Thanks for the insight. If there is air in the system, I assume it goes away? I Do not want to tear up anything.

Thanks again!

Thanks for the insight. If there is air in the system, I assume it goes away? I Do not want to tear up anything.

Thanks again!
It may go away by itself but not always. I would just suggest getting the system flushed before winter sets in.

It may go away by itself but not always. I would just suggest getting the system flushed before winter sets in.
Thanks for the suggestion. I will have it flushed....Appreciate the help!

Jibit is right. Its a vaporlock kinda thing where air gets trapped in the system.

MAKE SURE they read the instructions before they flush it. The cooling system is a closed, pressurized system, and they have to refill it correctly or it wont be full an you'll have the same problem.

Jibit is right.
Stop saying that or I might start to get an ego problem.....too late!:N

Jibit is right. Its a vaporlock kinda thing where air gets trapped in the system.

MAKE SURE they read the instructions before they flush it. The cooling system is a closed, pressurized system, and they have to refill it correctly or it wont be full an you'll have the same problem.

I was going to flush it myself. I was unaware this is a sealed system. Any suggestions how to do this correctly so it does not mess up anything?

I was going to flush it myself. I was unaware this is a sealed system. Any suggestions how to do this correctly so it does not mess up anything?

There should be instructions on a label on the fender well ---- or the owners manual ---- the key is where you fill it.


You cant flush it yourself, that requires a machine. Flushing is different then changing ----

There should be instructions on a label on the fender well ---- or the owners manual ---- the key is where you fill it.


You cant flush it yourself, that requires a machine. Flushing is different then changing ----
I have a flush tool with air. I have done this several times.... Thanks for the hint. With more research, I found out there are air release valves.... The location is not yet know...... :biggrin: