I posted in the General about my car overheating and it happens mostly when im at lower speed as opposed to higher speeds (Havent had a problem overheating whenever I drive on the highway). One of the possibilities someone mentioned was my fmic blocking my radiator during low speeds cause increased temps. The can get really high tho sometimes.

Anyone else every have this problem? How can I make sure/rule out the FMIC as being the overheating problem? How did u guys solve this? Thanks.

heres a pic of my FMIC:

You have seen your cooling fan running, right? I had that happen, plug wasnt in all the way and it fell out. Same symptoms though, anything above like 25mph and I was fine, anything lower, I resorted to cranking my heater to try to cool everything down, in mid summer.

Sucked

Good luck
DJ

What you are experiencing is common. XtremeRS and I both had this problem with a hahn FMIC. We fixed it by wiring the AC fan to run all the time and installing cooler thermostats. That should take care of it. You FMIC is blocking to much air for your radiator.

A FMIC will hardly cause your car to overheat, at least it never happend with mine. However, my car did overheat once my fans stopped working and from the overheating the head gasket just gave up. I was leaking preassure and heat into the coolant passages. My overflow tank was always filled with boiling coolant. ALso, if I drove and kept the air comming, the car would be cool, but it is alsmot always top and go traffic. I changed the head gasket and all was fine.

yea guys something serious is wrong. Today for the first time it didnt want to be cool even on the highway. I was close to my house when the gauge read ALL THE WAY UP and so i made my way home. When i got home the coolant resevoir was bubbling a lot and it leaked all the coolant out. It spit it up out of the extra open tube coming from the resevoir and now its all ove rthe driveway. It was steaming from the resevoir too. Something big is fucked up and I dont know what. My water pump was changed and so was my radiator cap. Any BIG ideas? My rebuilt block was just put in and i picked it up 2 days ago so it cant be the headgasket. It overheated before the new block but not this bad. That may eliminate soem possibilities.

well if it's the stock radiator, it's probably not going to handle the boost pressures too well. i don't know if you've done this but you also have to change your pressure cap to the 16psi ones. the stock one is too low. when i changed, it improved. i also added water wetter to my 50/50 coolant mixture and it was way better. i did hard boosted runs and no overheating. i haven't changed my radiator as well, but i'm about to invest in one. i know once i put this new turbo on, it's going to be toasty.

Ok I'll look into changing the cap. But do you really think this is the problem? Seems a little simple for the big mess it made.

i dont think the cap is the problem. the only way the cap could be a problem is if you notice it leaking. when its leaking it will cause your res. tank to fill and overflow.

i say you check to see if your thermostat is opening all the way. take it out, boil it in water and see if it opens. if it does, good. if not, replace it.

i have my fans wired with a relay. when one fan kicks on. ive never had a problem with the hrc fmic causing the car to overheat.

you may want to check to see if your AC condensor is not overheating, causing the radiator to overheat.

I say do a leakdown test too. You have the same symptoms as I did. I replaced all hoses, thermostat, put in a C&R aluminun radiator, another rad. cap and still I would get high temps. I changed the head gasket, and even in 90 degree weather I would stay cool. Hope it helps.