I tried buying thermal paste at Autozone and Advance Auto and the guys look at me like I have two heads. They all pull out dielectric grease or bulb grease. I explained tha they are not the same but they insists that that's all there is. I show them the little tube of white thermal paste that comes with the new ignition module but they all say thermal paste is the same as dielectric grease.

My neighbor found a little tube of thermal past at Radio Shack. I'll head over there to get some. I'll post the stock number when I get it.

polydimethylsiloxane

I went through this last week and you enter the land of Chemistry language. I think the stuff that comes with the ICM was called:

polymethyldisiloxane...

I don't know if that is a typo or if there really is a huge difference...

[This message has been edited by Gall757 (edited 08-07-2011).]

yes Radio Shack always carries it or any good electronic part store will have it. Most electronic shop will know it a Heat sink grease.

Funny how this topic comes up all the time..

[This message has been edited by Dodgerunner (edited 08-07-2011).]

Building computers, I use a product called Arctic Silver and it is made with 99% real silver to transfer heat. It has a peak operating temp of 180 degrees. I have no idea how hot the module gets but the silver content would really help heat transfer.
http://www.arcticsilver.com/as5.htm

My take on the ICM failures is that many of them are caused by high resistance in the secondary arcing back to the primary. Just a guess but it seems like certain people just have had horrendous problems with repeat ICM failures. Perhaps the problems were always with a high resistance secondary causing this arcing.

Yes I do believe they can fail thermally also. Yes for sure use thermal paste under the ICM.

It seems like many ICM run for decades without failing. And it seems like once they fail, the next failure for many is not that long away. Yes it could be blamed on poor aftermarket parts too.

I think whenever an ICM fails, even us cheap Fiero owners should ohm out our spark plug wires and/or replace them. And I think the Ignition Coil should be replaced anytime an ICM fails. Compare the cost of an ignition coil to the cost of an ICM and a tow.

Also - it has been said before but here it is again. Never have a spark plug wire disconnected when the engine is turning. The extremely high voltage that results in the coil can blast new holes through it's insulation and cause troubles in the future. If you want to determine which cylinder is not firing, GROUND the spark plug wire, not disconnect it.

[This message has been edited by phonedawgz (edited 08-07-2011).]

quote Originally posted by IMSA GT: Building computers, I use a product called Arctic Silver and it is made with 99% real silver to transfer heat. It has a peak operating temp of 180 degrees. I have no idea how hot the module gets but the silver content would really help heat transfer. http://www.arcticsilver.com/as5.htm

This is what I have underneath my ICM- been holding up for the last 3-4k miles.

No kidding. It's getting really difficult to get good parts anymore. I asked for and insisted on a genuine Delphi fuel pump, not some made in China crapper, and got one made in Mexico. The Mexican made stuff has treated me far better than China. I've had faulty brand new parts far too often for it to be an anomily. Throttle position sensors, fuel pumps, even a couple of dead spark plugs. Plug wires that light up in the dark, junk distributor caps, three tries to get a good starter for a Nissan, and on and on. I bought an alternator that had a necessary threaded hole, and the hole was cast so large their tap barely made an impression. I had to take it up a bolt size to use it. Don't get me started............

quote Originally posted by Hudini:

See, part of that picture is what concerns me....the words "silicone based". A lot of the top manufacturers of heat sink paste pride themselves on NOT being silicone based (Like my link above). I don't know if that creates a slight breakdown in the products ability to remove heat.

If you can't get to a Radio Shack, NAPA Parts stores carry little single serve blister packs of the clear heat sink or thermal grease. A little expensive compared to the Radio Shack product, but when nothing else is available------

Any computer shop will have the good stuff as well. (Tiger Direct / Comp USA for instance) Same stuff as used for mounting the CPU on your motherboard.

After some digging on Wikipedia....

The base goop is usually silicone....or polydimethylsiloxane...the stuff they make silly putty out of. It is also called di-electric grease.....and is used because it is not a conductor of electricity.

In order for it to be considered 'Thermal Grease' some filler must be added to transfer heat. Silver or Aluminum or Carbon....

What I saw at Advanced Auto in the box with the ICM was di-electric grease....so here is another area where aftermarket parts may be giving us trouble. It appears that some ICMs are being packaged with di-electric grease.

[This message has been edited by Gall757 (edited 08-07-2011).]

Stupid question....does Google search automatically link to the threads title? I have seen this in a few threads now:

quote Originally posted by IMSA GT: Stupid question....does Google search automatically link to the threads title? I have seen this in a few threads now:

That's not a stupid question at all....the internet salesmen have been working on this for years......in order to increase advertising revenue...looks like it is finally here....

quote Originally posted by IMSA GT: Stupid question....does Google search automatically link to the threads title? I have seen this in a few threads now:

Not quite. Google AdSense uses the content on the page, to determine what ads get shown. So if the thread title was one thing, and the conversation quickly devolved into some argument about a different thing, the alternative would show up more in ad results, than the thread title. I bet the ads in Totally O/T are weird.

Looking at the relatively high cost of ICMs, it would seem we would want the best heat sink compound available, They all seem to have have similar thermal conductivity coefficients, the largest difference is their abilty to withstand higher enviromental temperatures. That being said, Dow Cornings's DC-340 seems to take the lead - a little pricey up front, but considering most other compounds have short term temperature exposure limits only as high as 50ºC (122ºF) (which is about the normal operating temperature of many PC CPU and other electronic components). It would make sense that we consider the temperature extremes the ICM is exposed to in the Fieros' engine compartment. DOW 340 resists changes in consistency at temperatures up to approximately 350ºF (177ºC) and has a maximum operating temperature of 392ºF. It heat is indeed the culprit for repeated ICM failures, it would be less costly to give this compound a try, it could prove to be money well spent.

[This message has been edited by 86gt2.85 (edited 08-07-2011).]

Don't overlook the mounting screws. The ICM grounds through the mounting screws to the base of the distributor. Make sure they aren't rusted or corroded so you get a good ground.
I use thermal paste for computers and it works well. Pick whatever brand you prefer.

quote Originally posted by fierofool: If you can't get to a Radio Shack, NAPA Parts stores carry little single serve blister packs of the clear heat sink or thermal grease. A little expensive compared to the Radio Shack product, but when nothing else is available------

Thermal paste is never clear. If it's clear it will NOT work and is not the right stuff.

go to radio shack and buy part number 276-1372 http://www.radioshack.com/p...sp?productId=2102858 from them and use that. It's perfectly good stuff and will work well.

Most important aspect is the mounting surface is clean and flat. you need to sand where the module sits lightly with 1000 grit then smear a very thin coating of the heat sink grease across the module and attach it. a lot of grease will cause it to fail, the grease is only there to fill in the gaps between the two surfaces.

Honestly, I dont understand why modules do not come with a small tube of it, It's so cheap and you need a dab a little smaller than your pinky nail.

[This message has been edited by timgray (edited 08-07-2011).]

quote Originally posted by timgray: Honestly, I dont understand why modules do not come with a small tube of it, It's so cheap and you need a dab a little smaller than your pinky nail.

All the ones I've bought, come with it. But if you are rebuilding the distributor, you probably will need more, when you are re-assembling everything.

quote Originally posted by Carrolles: I tried buying thermal paste at Autozone and Advance Auto and the guys look at me like I have two heads. They all pull out dielectric grease or bulb grease. I explained tha they are not the same but they insists that that's all there is. I show them the little tube of white thermal paste that comes with the new ignition module but they all say thermal paste is the same as dielectric grease. My neighbor found a little tube of thermal past at Radio Shack. I'll head over there to get some. I'll post the stock number when I get it.

The point Carolles is making here is that you have to watch out when you go to the chain auto parts stores. Even the grease packaged with the ICMs they sell is wrong.....it's clear grease....di-electric. They have little packets that they sell at the register and that is wrong too.

The paste that came with the GM ignition module I bought from the chevrolet dealer was white and very dense. Is the white possibly titanium oxide to give the heat transfer properties?

[This message has been edited by Carrolles (edited 08-08-2011).]

The clear stuff won't work WELL, but it IS better than nothing. Since it's a grease, it will conduct heat better than air, but not as well as the white stuff (thermal compound).

Speaking of getting the wrong stuff at parts stores, one time I went into an Advance Auto looking for grease for the brake caliper sliders. They tried to sell me disk brake quiet stuff, which is the opposite of a lubricant, and I couldn't convince the idiot there otherwise.

I had bought an ICM the other day and installed it with the stuff that came with it, but it was clear.
I went to Radio Shack today and got the item suggested above.
I remounted the ICM and I`ll see how it works.
Mike

I happent to work for Autozone and if you ask for thermal paste and they can't find it it's in the engin management ignition plan o gram with the icms. It's in a small box with two packets inside

i worked for what is now called oreillys for over a year and there are soo many uninformed people working for these part stores its rediculous. i had 5 years of backyard mechanics before i worked there, so i knew my way around cars a little bit. after i learned the system i was able to help alot of people that couldnt get it elsewhere. a good example is this:

guy comes in pissed off and slamms his old ford fender mounted starter solenoid on the table. he states that he was at autozone, and another of our stores and no one could find this part for him. So my first question is what did it come out of, since you have to put in the year/ make/ model/ engine size etc to start to find parts. he says its off his RV with a 454 bbc. i told him that his part came off a ford starting system. within 30 seconds i had pulled out 5 different soleniods for him to choose from, one of which was a HD unit cheaper than the rest with a lifetime warrentee from BWD.

you dont have to know anything about cars to work at a parts store, and thats the problem. i went into my old store the other day for something and i saw a long time employee telling this guy with a newer chevy P/U to use the house brand green coolant. then i had to spend 10 minutes informing her and the customer about organic acid technology, and how it can eat through water pump impellers if you mix the wrong coolants together.... sigh.. im not saying everyone who works at the chain stores are ignorant, because there are alot of good ones out there. its just finding them thats the problem lol

/end rant