While traveling at the end of a 200 mile trip in my '05 STR with 86K on it Thursday, I noticed that the "Restricted Performance" message had come on along with the amber warning light as well as the check engine light. I had not noticed any change in engine speed, acceleration, nor did I feel or hear misfire or other strange noises but immediately checked other gauges to see if something else was happening and then noticed that my temp gauge was flat-line dead. I was very close to my destination so I forged on and then parked the vehicle.


The next morning I started it up and all was good; no error message, temp gauge working fine. After about 40 miles of highway travel, the same chit happened, again with no seeming performance change. When I got back home and after a hour of rest and cooling down, and with just local city traffic, it is not having any more message or gauge issues. Does anyone have any insight as to what might be causing this intermittent problem?


It may or may not be meaningful but the outside temperature was somewhere around 3 degrees with a wind chill factor of -12 degrees.
I suspect that when driving at 65-70 miles an hour for several hours the wind chill ratio for any exposed mechanical and electronic pieces would be more like -40 degrees.

 

Stop driving it! You risk a catastrophe.

For goodness sake read the codes and look 'em up in the free downloads (JTIS / codes pdf) or post them.

People drive in much worse temps and get zero problems.

 

Sounds to me like your coolant might be weak and you are getting a frozen radiator.

 

Paul-

I think you're a brave man for driving with a dead engine temp gauge and the RP warning illuminated. I'd immediately check the coolant level and it's freezing point. It's possible that the coolant level is so low that the temp sensor was no longer submerged. If that's OK, I'd start reading codes to see if there is a fault with the coolant temp circuit.

As an aside, note also that the 'wind chill factor' does not apply to anything except humans. It's intended as a reference calculation of how quickly heat is removed from exposed skin by the effects of moving air, and reflects an equivalent (not actual) static air temperature.

If exposed skin at a static air temp of 3*F is subjected to 10 mph winds that render a wind chill factor of -12 as in your example, the skin will go no colder than 3 degrees no matter how long it is exposed.

Similarly, a lump of inanimate metal or plastic cannot become colder than the air that surrounds it, in other words it will be at 3 degrees no matter how fast the wind is moving.

 

Simply not true. If that were true, there would not be any reason for a radiator cooling fan. The air around the radiator is cooler than the radiator, right?


Air movement increases heat loss and for that reason, any residual heat will be lost by moving air.


I would recommend rethinking your answer.

 

No, re-think yours!

 

I'm not surprised by our friend's answer above. Many people do not understand and cannot grasp the concept behind the so-called wind chill factor. I had a colleague many years ago that was convinced it was called the 'windshield factor' and always parked his car with the nose facing down wind to stop the engine from freezing.

 

Knowing that heat (energy) flows from hot to cold in wind (moving air) helps a lot.

To get to a colder-than-the-air temperature requires more than just some moving air since otherwise energy is just not going to go from the colder item to a hotter one.

I suppose thermodynamics is the sophisticated term.

 

Exactly. Heat will be lost from an object or fluid until its sensible heat content is equal to its enviornment,( ambient temperature), provided that enviornment has less heat ( "colder") than the object/fluid.

To obtain less heat than the ambient temperature, a mechanical means of removing heat must be used such as the refrigeration system, ie: air con, refrigeration, absorption cycle, etc.

The radiator cannot reject the heat fast enough from the coolant versus the amount of heat the coolant is removing from the engine so radiator fan(s) help by accelerating that heat removal by moving the ambient air through the radiator.

I don't mean to insult anyone's intelligence, just elaborating on JagV8's reply.

Mikey is spot on with the wind chill explanation, btw.

 

Please let us know if you have enough coolant and if it was freezing in the radiator or not?

Might be a good time to just swap the coolant out along with a new thermostat. Of course I would wait until it warmed up a bit first!!
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Fluid levels were Ok when checked and was hard to tell if there was freezing in the radiator. The vehicle only exhibited the problems after being driven 50-ish miles or more at a time.......not when normal daily-driving distances to and from my home and business. There is the distinct possibility that some incorrect anti-freeze was mixed with the specified type by the PO. By this time tomorrow there will have been a new water bridge, thermostat and fresh fluid installed. To my understanding there was a typical crack in the water bridge. We shall see if that is all I have to worry about other than replacing the dreaded hose under the supercharger.

 

I hear you on the SC hose but I have done a lot of reading and searching and have come to the conclusion that the hose is not guaranteed to fail.

Several guys have gone as long as 167K miles with the original hose. I don't like it but I have prepared by getting all the parts (Mainly gaskets as the hose is only about $25).

Kind of like bringing an umbrella. It won't rain unless you forget that umbrella!!
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