Heatmaker

Alright I've been having some trouble with my ICM and heat soak, ever since my car over heated one day. When I trouble shooted with the unit I unbolted it from the coil bracket, and wraped heat tape around it and strapped it to the rubber part of my intake. WHen I ran the car for a while I thought I was ok, then it shut off. I went to check the module, and it was burining hot, So I went and decide well maybe the hot air got to it. So I got some wires, and relocated the module to the front of the car near the fuse box. I ran the car, and I noticed that the module would heat up. Even when it wasn't attached to the coil. IT would get burning hot, and then shut off. Okay maybe just a bad module. So I went and swapped it on a warranty at autozone, and hooked the new one up in the same remote location. This time I hooked it back up to it's original Bracketry, and smeared the White heat goop on the back of it. I start he car up, and this one two started heating up, and shut the car off when it got boiling hot. Even when it was far away from any heat source. Just what in the hell can this be? and why is it heating up like that? What might be causing this? IS the normal?

Kevin Blown 95 TA

You know the finned aluminum thingy?- That is a heat sink. It needs to dissipate heat somehow - into the air and some other metal. Best to mount it to some metal bracket off of the head, then it will live it's life as the GM Gods intended. Don't just tape it to the intake. JFC!

joeSS97

What he said.^ And WOW.

Heatmaker

So how does the ICM work? and why does it heat up liek that?

Kevin Blown 95 TA

You really want a lecture on ESR (semiconductor resistance)? Basically, the computer tells the ICM, which is an electronic switch, when to fire the coil, but the switch is imperfect, and creates heat as it conducts, so you got to get the heat away from it so it can continue to function in a super bad-*** F-body mode with a limit of 125C or so, Now you can see it needs heat transfer much like your engine need a radiator to take away heat from the heads & block.

Heatmaker

never new that. so how does the ICM spacer work. If the ICM is heating up, and it's spaced away from the heat shield, how does it transfer the heat properly?

TobyZ28

I've always wondered the same thing about the washer mod with the ICM. To me it always seemed like spacing the ICM would make it harder for the ICM to dissipate the heat into the block...

wrd1972

Uh huh,
The head will be a given temperature, the ICM will not raise or lower the head temperature. I saw in a post way back that someone measured the temp of the heat sink and it was around 160F when spaced out. The head will be a bit warmer than this , therefore the ICM temp will be raised if it is directly attached like stock. The ICM will also remain hotter longer after the engine is turned off if it it directly attached to the head due to the entire head taking longer to cool off. The spacers separate the main surface area that joins the head to the ICM.

If you want you can rig up additional heat sinks to the ICM, this should help to lower the ICM a bit. There are many people that swear by this mod.

Honda Hunter

As long as the washer can disapate heat it's still serving the same purpose correct?

96arcticwhite

http://shbox.com/1/4th_gen_tech2.html#ICM_cooling
If anybody is interested.

I'm doing this one too because I noticed that the coil gets hot also. If you're crafty with aluminum then you could make copies of the steel brackets but with some more area to dissipate more. I'm just going to washer it and see what happens. Or extend the harness and coil wire and stuff the whole works up near the CAI!

wrd1972

I would think so. You might even try non metallic spacers like a high temp safe plastic. I am going to snag some junk heat sinks from work and play around with them. If you want to really play around I don't see a reason you could not install a 12v heat sink fan down there. Every little bit will lower the ICM temp.

Also make real sure you have an ample amount of the temp conducting grease on the back side of the ICM.

Heatmaker

I just attached the ICM with heat sink to the front of the fram near the Intake... will that work?

Dave89IROC

as long as there is some airflow, it should

nodnarb481

Im going to do this mod just like shoebox says to in his sight. but what kind of termal grease should i get? and where exactly do i put it?

wrd1972

It goes directly under the ICM module. What kind of grease is it? I will differ on that one.