overheating need help!!!!

my 97 gst keeps overheats when i'm stuck in traffic and when the turbo spools up. once i'm on the freeway as long as the turbo isn't boosting it runs just fine. it has a greddy fmic. what could the problem be? i just bought it for $2000 and expected it to have problems but this one i just don't understand. the only mods done to it are the intercooler, a turbo timer and a boost gauge.

$2000 FOR AN INTERCOOLER??? are you insane... what a rip off, but i guess thats GREDDY/GREEDY for ya, how big is it? that is probably your problem if its overly huge and blocking the radiator! why is that one of your first mods anyways? not trying to bash you but for that $2000 you could probably be damn close to a 12 second car if you would have bought other mods besides a FMIC that basically doesnt really help much right now on a stock turbo!

I heard that huge intercoolers dont present problems when they block the radiator because the airflow cools the sytem down so much that the radiator becomes redundant, whatever that means. SO RS-T, what is the perfect size of an IC one should run with a 16G then?

Guys, I think he was saying his car was $2000 not the IC. Why dont you buy a spal or t-fal or whatever fan for your radiator? They're less than $100. Or u could get a fluidine aluminum radiator for like $350 i think. That is a strange beggining mod though. lol, tiny ass t-28 and a greddy fm. Look in your coolant resevoir or radiator and see if the coolant is at all discolored or mucky. That could cause your problem. If it is then you need to flush your system. If ur in traffic though, your temp will go up. I think just cause there's no air hitting everything. You can turn ur a/c off or turn ur heater full blast. That should help. There's a bunch or other things that could go wrong but I dont understand the many different parts of the system to help you. Maybe Kevin will help.

I dont think the T-28 should be called tiny-ass though, lol. that thing hauls ass. did u mean t-25?

Oops! yeah, t-25. I have forgotten so much stuff lately. I didnt mean it literally man. Just compared to other turbos or needing an aftermarket fmic. Not tryin to offend anyone with the stock turbo. Hell, it put me back into my seat when I test drove one.

T-25 IS a FUCKING tinny ass pussy.. it's ok .. you can say it. because it's the truth LOL i am not one of those going and braggin around how BIG my t-25 is and how powerful it is. LOL... it's FUCING SMALL lets all face it.at the same time better than nothing now.. back to the topic lol

thermalstat maybe? does your fan kick in at the right time? does it over heat according to your temp gauge or you actually pop the hood and made sure that DAMN YOU"RE HOT!

First things first, DO NOT let your coolant temp get to the red mark. I would pull over if it goes up more than 90%. You can blow the HG, or cause other severe engine damage if you drive the car past the red mark. Try to avoid driving the car altogether until the problem is solved, except to test what you've replaced.

Overheating problems can be a pain in the ass, especially if you can't figure out what is causing them right away. Your temp drops on the highway because so much air is moving through the front of your car, the cooling system, and the engine compartment itself...heck, while I was driving my overheating car I would sometimes pop the hood to the release point (not all the way up) and drive like that to get a little more air cooling the engine! Overheating problems are often solved inexpensively. However, go down this checklist, and hopefully you will solve the problem before the water-pump step...

Your stock water temp. gauge should not go above halfway up if your cooling system is working properly.

*You should pick up a Haynes manual for your car! It will tell you exactly how to do most of these steps if you are unfamiliar with the processes, and is well worth $15 at your local auto parts store!

1) Make sure radiator fans are coming on before the car overheats, with the AC OFF. If the fan(s) aren't coming on, there is a problem with one or more of them/there electrical systems.

2) Check coolant levels in your car and in the coolant reservoir bottle. If adding coolant does not work, flush the system and put in new fluid. Check for leaks under the car.

3) Replace radiator cap. This is an easy step, and a $5 part. If the cooling system is not sufficiently pressurized, it won't flow correctly.

4) Replace the thermostat. The thermostat is a little device inside one of the coolant pipes that opens when the car gets to running temperature in order to allow coolant to circulate around the block, then through the radiator, pipes etc. If the coolant is not circulating, it gets too hot around the block. This process is easy if you have a Haynes, and a new thermostat should be like $12. This was my problem with my previous overheating issue. After installing the new thermostat, you can put your old one in a pot and boil it. If the water boils before the thermostat plug opens, then your old thermostat was the problem, and coolant was not circulating properly.

5) If none of those steps has solved the problem, it is time to take the car to a mechanic, or continue on the steps yourself if you're confident. A radiator flush may be in order; this should be done at a local radiator shop. If your radiator is clogged 50% or more that could be what is causing the problem. If you notice your temp go up a bit past half way, but not rise above that, your radiator is probably clogged. If it goes up all the way to almost the red line, it is something else (that hopefully you've already replaced ;))

6) The water pump would be the next logical part to replace. It is a PITA to replace, and you must take the timing belt and all accessory belts off to change it. If an impeller has broken or bearings are bad, it could be failing. A whining noise is a sign of bearing failure. Step-by-step guide in the Haynes, or $350 with parts and labor at a mechanic.

7) As a last resort, your head gasket could be leaking exhaust gas into your coolant and raising the temp. This is rare, but possible. Soultion=HG replacement.

8) If your car is still overheating, you should take it to a mechanic, tell them what you've done so far, and see what their next suggestion would be. I'm confident you will have solved it already by this point.


Good luck and keep us posted on what the status is! :D

Good post joe. Your car might be overheating due to the FMIC, something else, or both. Solutions to a real problem are in joe's post, while you can buy better/slim fans for your radiator as well as new radiators as said above. I'm guessing it's something like a thermostat and not the FMIC.

9) Water wetter. Additive, supposed to be more effective at releasing heat. It's worth a try, a lot of people use it.

Water wetter is a great idea. Try to solve the problem before trying it, if you can. If you HAVE to drive the car to get to work or what not, put in some water wetter to make sure it doesn't overheat. But definitely try to solve the problem first, so you're just not "patching the hole with scotch tape", so to speak.

What about a coolant temp sensor (there are 2 I think)....one for the gauge and 1 for the ECU. If the one for the ECU is bad, I don't think the fans will turn on. Maybe this is the problem. :dunno: