Here we go again-temp issues

[sierraspider]

It's crazy hot here in Calif. My 82 FI spider has no temp issues if I'm rolling along, but traffic causes it to overheat. Checked thermostat with candy thermometer in pan about 6 months ago(Drilled small hole as others have done to help burp). Was fine. Checked temp gauge with thermometer at top of radiator, readings the same. Installed new fan sensor doesn't work until around 215, so I put in manual switch, but even with fan on early (at 140-150 or so) eventually it gets hot in traffic or slow uphill running. Radiator was completely refurbed and new cap. So back to basics. How can I tell if thermostat is opening and if air is completely out of system or anything else I'm sure I overlooked. I'm sure there are a few posts about this but I didn't find the one that seemed to address my issues. Thanks again


Dan

[toplessexpat]

Do you jack up the front when you top up the coolant, or have a T in the top of the heater hose?

[majicwrench]

Define overheat> Guage pegs?? Coolant pisses out everywhere?? What problem are you having??

As you know, fan switch should come on about 200. So right there you have a problem. Why doesn't it come on till 215??

Again, what is your version of "hot"??

[TX82FIAT]

Dan, other than the temp gauge inside the car, are there other signs of overheating. you said you checked the top of rad and readings were consistent with the bottom. That is a good sign indicating you have good flow through the radiator. what was the temp reading at that time of the rad? You can tell if your thermostate is opening by feeling the hoses leading into and out of the thermostat. A cold hose indicates the thermosta has not opened. Is the overflow tank full when you shut her down after running 215 degrees. I'm wondering if your issue is electrical where 215 is really 190. If it is an overheating issue it would overheat parked in your driveway in the same manner it does in slow traffic. This gives you an opportunity to run it through some fan cycles and check the temperature at various spots top/bottom of rad, head, block.

It can take a few cycles to get air out of the system. Do you have a coolant T installed between the head and the heater pipe. The coolant T for a couple dollars at any autoparts store creates an easy high point in the system. Have you had to add coolant to the system?

[sierraspider]

Thanks for the quick responses. I'll see if I can be more specific. Car will get hot sitting or slow uphill (not pissing out water but according to temp gauge which I checked by putting candy therm in top of rad). Haven't checked lower hose for temp to see if it is cooler (therm opening). Bought a Beck Arnley fan temp switch never seemed to work right (temp too high, so I put in manual switch) Overflow bottle stays at same level, and I haven't had to add coolant/water. Bought generic rad cap (mistake?) Don't want to just randomly toss $ at problem so I'm looking for logical diagnostic steps. I always had feeling car was never burped fully. So if anyone has steps to diagnose I'd be grateful.
Thanks again for everyone's time

[majicwrench]

"Car will get hot" how hot is hot??

[sierraspider]

It would probably go into the red if I let it, but I stop short of that.

[So Cal Mark]

low speed overheating is a sign of too little airflow. The fan should come on at 195 and drop the temp to 185, then it will cycle off. I'd suggest getting an infrared temp gun and measuring the temps across the radiator. If it cools properly at speed, it should cool at idle if there is enough air flow through the radiator

[RRoller123]

Just my 2 cents. Mine has a fan overide switch too, installed by a PO because they couldn't get the system to cool. (I left it installed, in parallel with the correct system). All it needed was a proper burping. So I would go and burp it again. Jack the front end up as high as you can get it and make sure the heater system is on. Also disconnect the throttle plate heater and fill that and the hoses it connects to and you should be pretty comfortable that the air is out.

If it still overheats it is likely that you have a clogged radiator or a faulty t-stat.

Could also have your restrictor on the front of the engine installed backwards. It is possible to put them in backwards. The restricted (smaller hole) side faces the T-stat, the more open side faces the radiator.





Did you say that the fan comes on automatically, but not until 215F gauge? If so, I would throw another fan temp switch in there. They are not expensive. Auto Ricambi US and the other vendors all carry them. Fan should come on at about 195F gauge.

Good luck!

Pete

[4uall]

I have never lifted the front end nor do I have any fill modes

For what its worth this might help

http://forum.fiatspider.com/f08/viewtop ... verheating

[racydave]

Couple observations and questions. Like Mark said, the thermal guns are way cool, and cheap. It could be possible the gauge is off a little, but hard to tell since you get freaked when it goes up. I am always anxious on hot days in traffic too. Now a question, is the vacuum advance supposed to work at idle, or just off of idle with ported vacuum? I could see that it might run a little hot if the timing was a little too advanced. I have also heard that the lower cover is a help, but I run without one and do not have a problem. But, it is possible you really do not have a problem, and the gauge is a little off. Happy trails!

[azruss]

Your gage can vary depending on the quality of ground. My car reads 10 degrees high when the lights are on. If your water pump is old and tired it can cause overheating at idle. I rebuilt my entire cooling system with new radiator, stat, pump, cap. I also added a fill port in the upper heater line. I made sure the system was leak and air free as well as the overflow tank at the proper level. I am using the factory fan set up for an 80 fi. At idle and slow traffic in 110 degree Arizona heat, it doesnt show any higher than 200-210 on the gage and the fan is generally on all the time. You should be able to tell if the thermostat is working just by watching the gage. If it gets hot and then suddenly drops, that means the stat just opened. I agree with the others in that is sounds like your stat is opening ok and your issue is not enough cool air making it out of the radiator. This is due to air in the system, dirty radiator, bad cap, sticky stat, weak pump.

[bradartigue]

One way to make sure it isn't the pump is to let it get up to the 200 or so point and rev up the motor when at rest, if the temp goes down then the pump isn't working right at low speeds (get a new pump). But it sounds like you have circulation...

I recently received a bad fan sensor, maybe you have one as well.

[sierraspider]

Thanks everyone
I put in a "T", burped it properly and got rid of the AC stuff in front of the radiator. (AC not hooked up). Runs @ 190 on 100 degree days in stop and go traffic. FINALLY,YES !!! On to the next bit of fiddling..... Thanks again everyone, I've been able to get my spider really well sorted with a lot of help.

Thanks

Dan

[4uall]

WHOO HOO

https://www.youtube.com/watch?v=3GwjfUFyY6M