[excruisers]

My name is Gary and we recently purchased a beautiful 2009 Passion to tow behind our motor home. She came with all the towing equipment, wiring, battery cut off switch and only has 17,000 miles on the odometer. We are in Austin right now (and way too cold) and will be driving our new Smartie back to our home in Mazatlan, Mexico in a month or so. (much warmer weather there but here for the holidays) I have saved one of the take off front tires for a spare to take along on our trip.

I have already switched out the front tires and wheels so I can now rotate tires and boy does she handle better on the highway. I ordered a 451 cruise control on Steven's black Friday SUPER sale and just got it yesterday....so it is not installed yet. About two weeks ago I received and mounted the Ultra-guage primarily for the tach and engine temp monitoring capabilities. And herein lies my question:

The car warms up slowly in this 30-40 degree weather and once it is up to temp. it seems to like 188.6 degrees. BUT, as I drive down the street the temperature readout on the Ultra-gauge varies constantly and considerable between about 172.0 degrees and 188.6 degrees. I am trying to determine if this is because of the thermostat operation letting in cooled coolant or could it possibly be an air lock situation. When the outside temperature was warmer, I saw the temperature rise to about 205 degrees as I sat and idled and then it went down when underway. I'd like to hear from any and all people using the Ultra-gauge and what they see on the temperature readout so I can put my mind at ease or search for a fix.

Thanks for any input and thanks for all the communication between everyone as I have learned plenty already.

Cheers!

 

[HGB]

Welcome Gary,

My Ultra Gauge readout hovers around 190 to 199 degrees when the engine is warmed up.
Considering that the outside temperature is usually 65 to 83 degrees in comparison to your climate. I have seen 204 degrees briefly while standing at a traffic light, yet that was not common.
I can guarantee that if you went to a dealer with such a question, you would be told that it's within specs.

 

[excruisers]

Ultra-gauge follow up.

Thanks so much for your reply and feedback on your own personal car. I tried to post the reply I received from UltraGauge regarding the temperature fluctuations I had indicated but I am unable to simply copy and paste so I will attempt to enter their message below. I'd sure like to hear from more Smart car owners and what they see on their readouts. Thanks again.

UltraGauge reads the parameters such as coolant temperature from the ECM and displays them unaltered without interpretation. It is not normal for the coolant temp to jump around more than +-1.8 degrees F. It could be a bad sensor, poor connection at the sensor or a bad connector in the wiring. It's also possible that there is a defect in the ECM which could be corrected with a firmware update.

Please make a post on this thread if you have an UltraGauge and can provide your experience on temperature readings. Thanks

 

[Stretchmobile]

The smart car only has a 1 liter engine. It works harder on hills and head wind. Generates more heat. The water temp will reflect that load. That probably where your fluctuation is coming from. An F350 with two people in it is never taxed in normal driving and it's water temp will stay with in a narrow range.

 

[b322da]

Gary,

I'm just down the road from you and my weather tends to be much the same as yours.

I drive a 2011 I bought new, and installed an UltraGauge promptly.

With temps above 40 deg F little Munchkin holds a steady 194.6 on a level highway at highway speeds. With the cold weather you and I have been experiencing lately she has some fluctuation in the water temp. running around town dodging Aggie pickup trucks, but it does not concern me a bit. I think she is just having a little difficulty settling down given my stop and go driving. If I get her up on a level highway at 75 mph, even at an ambient temp of 35-40 she again settles down at 194.6. I have concluded that this is the temp the thermostat holds if you give it a chance.

All I can do is relate my experience, and not recommend doing something or not doing anything. As the saying was in the service, "Different ships, different long splices."

Jim

 

[jwight]

Welcome to SCoA! Our UG does the same - varies from 188 to 196 F even when it's 12 degrees out as it is now. Normal as far as I can tell.

 

[excruisers]

Thanks for the "local" information. Most helpful and I can fully understand the splicing analogy as I'm a sailing "excruiser" as my handle indicates. Best regards.

 

[excruisers]

In regards to my issue as stated at the start of this thread, I went ahead and burped the cooling system with the small hose on top of the engine. I removed it carefully, watching to see if any air escaped. Well, if there was any air I certainly didn't see it. I let it drain for about 10 seconds and it was two steady streams of coolant with no apparent air. While the reservoir was low, I added 1 oz per liter of Water Wetter. Then I topped it off with 50/50 Peak antifreeze. Upon starting up and driving it seemed to fluctuate less than before, going back and forth between 188.6 and 179.5, depending on if I was under load, coasting or idling. Not much change but a slight difference. One thing that was different was that it seemed to "favor" sitting at 183.5 for intermittent periods of time. Now let me add on thing.....today was about 59 degrees, well above the 40's we've had for quite a period of time. Perhaps this is what caused the change, I'm just not certain. I will continue to monitor as temps will be warmer in the next few days. Seems to me there really isn't an problem, just odd readings from the Ultra-gauge, unlike the standard temperature gauge on most vehicles.

Thanks for everyone who took the time to share their own experiences and ideas.