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TFI module: use dielectric compound or heat-sink compound

16K views 34 replies 15 participants last post by  cevtv 
#1 ·
The Advance Auto guy said I should use silicone dielectric compound on the connectors and the flat metal surface of the TFI module. He pulled a TFI module from the shelf and it comes only with silicone dilelectric compound, which is clear. The two times I've removed a TFI module if had a white compound on it that looks similar to heat-sink compound used for heat generating electronic components.

Isn't the purpose of the large metal-to-metal area to provide heat dissipation for the TFI module? If so, does silicone dilectric compound transfer heat as well as heat-sink compound?

Regardless, does anyone know what I should use on the flat metal surface of the TFI module where it contacts the metal body of the distributor?
 
#2 ·
White heat-sink compound.
 
#3 ·
The Ford manuals say to use silicone dielectric compound, but thermal paste would also work fine. Guess it doesn't matter all that much
 
#5 ·
Either will do.....
 
#8 ·
I am going to Radio Shack to get their heat sink compound. Thanks for the responses.
 
#9 ·
You use heat sink compound. Its amazing how many manuals have it wrong.

Delectric grease is just for electrical connections. Keeps them from corroding.

Im really not sure who was the moron who started telling everyone to use dilectric grease on modules. But that has got to be one of the biggest myths in the auto maint industry :rofl:
 
#10 ·
I always thought it was supposed to be thermal compound as well, but my factory Ford manuals say dielectric grease. I guess they revised that at some point, these are 85 and 86 manuals after all.
 
#11 · (Edited)
I always thought it was supposed to be thermal compound as well
Nope. :) They are used for very different reasons. Using Dielectric grease instead of thermal compound is just plain wrong. Dielectric grease can boil, run, "evaporate", etc. Thermal compound stays through out temperature cycles and doesn't "boil" off (unless the parts light on fire :)).

With the above said, when working on a car, I've used Dielectric grease when I should have used thermal compound because I have Dielectric grease handy in my tool box (small tube). And, having "some" protection for the metal (from oxidation. rust, etc) is better than nothing.

But, for the TFI, using Dielectric grease is not a good idea at all. The TFI gets too hot. The Dielectric grease *will* "go away". Plus, it "could" then even leave a film on the heat-sink which would reduce it's ability to transfer heat to the distributor.

Also, for a PC's CPU's heat-sink, using Dielectric Grease instead of Thermal Compound is another way of saying "I want to buy another CPU soon". :)

Joe
MS Elec Engr /Comp Engr
semi-Mech Engr
 
#15 ·
I tried searching the AutoZone website and couldn't find this part number.

Also, where can I find artic silver thermal paste? I've seen this product mentioned in other threads.
 
#14 ·
And the answer is .......

Thermal compound.

Artic Silver Thermal paste is a good example. The entire purpose of putting some thing on the back of the TFI module is to disapate heat and keep thre TFI from burning up. If I'm not mistaken Ford changed where they mounted the TFI to keep engine heat away from the circuit inside.
 
#18 ·
Last question, I promise.......



I checked the Radio Shack site and found two Arctic Silver products listed:

Arctic Silver - Silver 5 for $9.99 (Radio Shack # 28-1099)
Arctic Silver - Ceramique for $6.99 (Radio Shack # 28-1098)

Which one are you guys using?
 
#19 ·
Either one will work

Either one will work

Arctic Silver - Silver 5 for $9.99 (Radio Shack # 28-1099)
Arctic Silver - Ceramique for $6.99 (Radio Shack # 28-1098)

Ceramique has some properties that might be of benefit to sophisticated electronics components but for our application, a TFI bolted to a distributor, both are equal.
 
#20 ·
Thanks for all of the informative responses.
 
#22 ·
Thats not a bad price..Plus you dont need as much as you think..I have a 3 ounce tube that has lasted me thru 6 computers and my TFI module with some left over..
 
#24 ·
#35 ·
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