Temp Fluctations

[sierraspider]

My 82 FI is all over the map as far as temp. Typically if I'm out cruising it seems to run cold (150-160) according to the gauge, but once I get into stop and go situations it really starts to climb until the fan kicks in. I've tested thermo with candy thermometer and it worked perfectly. Radiator was recently refurbed and has new water pump. Any ideas?

Thanks all
Dab

[divace73]

if it's not overheating it's not such a bad thing, the only thing I can think is that your thermostat may be stuck open??

[wizard124]

I'm glad you posted this....

I have noticed my car acts pretty much the same way. I didn't know if this is normal for these cars or not Mine has never overheated since I've owned it. The fan kicks on when needed. During my very limited highway driving (old tires), the temperature holds steady. In the city, it runs up to 190+.

Normal? I'd like others to chime in.....

[majicwrench]

Sounds basicly normal to me.

[toplessexpat]

This sounds pretty much normal to me.

Something that has puzzled me for a while (until a much wiser man than me gave what sounds like a sane explanation), is why does the temperature climb when you put the heat on? I've grown up with (on fairly poorly maintained cars caused by low cash levels during student years) the idea that as you overheat, you crank on the heat to dispel some of that excess temperature. That the wee beastie's temperature goes UP whenever the heat is on did puzzle (although it didn't overheat).

Transpires (and this is what sounds like a sane explanation to me) that when you engage the heat, the increased length of circulation path through the heater matrix leads to a drop in the quantity of water in the engine itself, and that leads to an increase in overall engine temperature.

Heck - it seems to make sense to me!

Andy

[GeorgeT]

It sounds like your thermostat is stuck in the open position. Also, check your radiator cap.

[kilrwail]

The behaviour of your temperature gauge is normal, especially if you live in a hot ciimate. The slower the traffic jam and the hotter the ambient temperature, the higher the gauge will read, until the fan comes on. That's the reason it has a fan!

Moral of the story - stay out of traffic jams and drive!

[narfire]

Yeup, Peter is spot on. Mine does exactly the same. When it hits 190 in the Tim's drive through, fan comes on and temp drops. This am took the Fiat to work for the first time of the season and temp did not get above 120 or so as the air temp was just above freezing.(20+ deg C later in the day) Again in the Tim's line up it started to climb but got my tea and was out of there before it went to 190.
Chris

[azruss]

for years i ran the fiat using the heater to drop the temp. It would allow the car to run 10 degress cooler with the heater on.

[TX82FIAT]

Yep, completely normal to have a cooler engine while fresh air is circulating because car is moving. Normal for the temps to climb at a stop light. All FIAT owners have a fixed eye on the coolant temp gauge when stopped at a light on a hot day. Trained ears are listening for the fan to come on right around the 190 mark. On my current car the fan will sometimes stay off for an entire day of driving only to kick on for a few minutes when i pull her into the garage and shut her down. I have an air temperature gauge and the car is inhaling under hood air at 78 to 105 on the highway. When i stop and the airflow is greatly decreased the air temp gauge rises as does the coolant temp. I have also used the heater to help cool down the car on other spiders owned. If you have a properly bled coolant system and you turn the heater on you are not taking any coolant away from the engine. You are moving a higher volume of coolant through smaller hoses and pathways. If your car gets hotter with the heater on i would suspect there is a problem at some point in the heating portion of the cooling system.

[toplessexpat]

Really?
Hmmm...... I need to go "a fiddling" then?

A

[dmwhiteoak]

Andy, Don't go to fiddling with it too much. It's running pretty good now.

[TX82FIAT]

My grandfather Pasquale Puliti from Abruzzo (family calls it Abruzzi) has a great saying that applies to FIAT Spiders. "If it aint broke, don't fix it." Then again, that man never changed the oil on his cars. He would just add oil and sell his car every three years.

[toplessexpat]

Andy, Don't go to fiddling with it too much. It's running pretty good now.

More noise doesn't necessarily equal better.....

[wizard124]

Transpires (and this is what sounds like a sane explanation to me) that when you engage the heat, the increased length of circulation path through the heater matrix leads to a drop in the quantity of water in the engine itself, and that leads to an increase in overall engine temperature.

Andy

The heater core acts as a second heat exchanger. The coolant quantity does not change. Opening the valve merely allows the coolant to circulate through the heater core.

When running hard up-hill on a hot day with the temp gauge climbing, turning on the heat will aid in keeping the coolant temperature under control.