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Discussion Starter #1
I am sorry in advance for so many questions ... does anyone happen to know what the temp diff should avg between the inlet and outlet of a 1986 alfa quad radiator ..or to put it simply...how much of a drop should a clean radiator give you at idle and then at operating speed....20 degrees 30 degrees etc...
v/r
chris
I do have a infrared thermometer for taking temps...just would like to get an idea what i am looking for ...
thanks again this is proven to be a fantastic resource ...sometime a little difficult to peal back all the layers in the sticky s to get to the answers at times :)
 

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You are looking for about 180 (depending on the T-Stat temp) at the inlet (top) of the rad. I can't tell you the temp drop as that would require a ton of additional info.

What is the specific problem?
 

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I just went through this with my 92 spider. My dashboard temperature gauge would sit 1 1/2 notches over 175 (202 degrees) durning driving and 2 notches over 175 (212 degrees) at idle.

Here are my results.

Coolant overflow tank idling checking with digital meat thermometer.

Dashboard Temp gauge reads: 212

Digital thermometer actual temp 180 degrees

The coolant overflow tank temperature increases to 185 degrees and then the electric fans start up, and the temperature decreases to 180 degrees again.


Radiator temperature idling checking with an infared heat gun. (dash gauge still reads previous temps)

185 degrees at idle

increases to 190 degrees and electric fans start up, then drags the temperature down to 165 degrees with in seconds. Mind you, this is with the hood open, I am not sure how the open hood vs. a closed hood alters the real life scenario.

From what I find, there is a 5 degree difference between the radiator and coolant overflow bottle.

I feel comfortable my operating temperatures are within range.

I hope this gives you some comparative information.

Kevin
 

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Discussion Starter #5
yes that is sort of what i was looking for i will take readings tomorrow and post results...looking more to see if you can see a drop in efficiency in the radiator, ie to flush or not to flush...
by the by i hope i am not missing something the 86 quad has a constant on fan with the secondary fan comes on when you turn the AC on ...unless i am really mistaken ...NOOB that i am :)
thanks for the help all ..
rog on instrumentation,looking for a baseline to correlate real vs what shows.
 

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That's correct.

Should you ever be sitting in traffic and it seems things are heating up, there's a sensor in the mechanical fan's shroud that if functioning properly will kick on that electric fan even if the AC is off.

It also has the capacity to run after the engine is shut down and the key turned off.
And will do so until the sensor indicates things have cooled sufficently.

See the FAQ for pix and location of the sensor.
 

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Discussion Starter #9 (Edited)
ok think the issue is in the idiot light sensor and the gauge pick up sensor. These are the readings and locations ,
1986 Alfa Spider Quad.

Gauge Radiator Inlet Outlet Thermo Light Thermo Gauge Expan TK

Cold 0 77 73 65 86 70

Idle 100 77 80 68 70 71

Idle+10Min

175 136 102 138 124 77

Idle+20Min

189 133 98 164 126 78

Driving 3000 to 3500 RPM's

10min

225 164 122 167 158 91

50Min est ( total 1 hour est)

225 174 130 191 176 102



Thoughts comments ?
V/R
chris
 
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