Coolant Temp/Heat issues

[4g63-pwr]

I installed a PR FMIC on my '99 GST and have been having heat issues on the freeway ever since. It is fine at idle but obviously not getting enough air at speed under load. My cooling solutions as of now are:

- Mishimoto Aluminum Radiator
- Mishimoto Fans and Shroud
- Lower temp thermostat
- Pure distilled water
- The mouth of the front bumper has been trimmed and opened up
- Custom air diverter that catches air passing under the car and forces it up behind the FMIC, into the radiator
- JM Fabrication heat shield
- New radiator cap
- All new under hood exhaust gaskets (no leaks)
- Also used some sheet metal to encase the the radiator to keep air from flowing around it
- I've also done the DPDT Fan switch mod (as covered by luv2rallye here http://www.dsmtuners.com/forums/151319397-post11.html)
- Compression test numbers are solid as well

The car still runs hot at speeds with both fans running full blast via DPDT fan switch override even after doing all of this. The water pump was replaced with another OEM unit about 9 months ago. Is it possible that the has crapped out on me already? I'm running out of ideas to keep this thing cool. If anyone has any suggestions they would be greatly appreciated. I'm on the brink of just throwing this FMIC out and getting a SMIC.

I'm getting really tired of my GSX track slut car being WAY more reliable than my POS GS-T daily driver.

 

[lacroixdp]

new radiator cap, new thermostat and water wetter in my car. its full when i park her at night and by the morning its down a little but not a lot...should i just do a HG? 175k....

Is there a puddle of coolant underneath your car? Watch it for a few minutes after you run it hard and see if it leaks any coolant out.

 

[4g63-pwr]

Mine never quit running hot, till this morning. My alternator crapped out again at which point the coolant temps leveled off and was actually running just below middle on the gauge. WTF

I did not think of the crank pulley for some reason, I'll check that when I yank the alternator again. There has to be something hampering the flow of the system. My airflow through the radiator should not be a problem

 

[4g63-pwr]

So does anyone have a theory to why my alternator crapped out and caused the car started running perfectly?

It runs nice and cool and pulls strong now. The only thing that has changed is the alternator died. I saw it happen.... the car was running just a little warm, then the a/c slowed down and the engine idled up, battery and brake light came on and then the coolant temperature leveled off and has not budged since. WTF

I will be replacing the alternator this week so I guess we'll see if the coolant temperatures to go back up. I can't see how those would be related but it is obvious it was/is.

 

[mikyrc]

Hey guys, does anybody have an idea of why does my car have hard time to turn off the rad fan at iddle?
It seems the temp (logger) stay at 200ºF forever when outside temps are around 90ºF.

Once i'm driving the car at regular speed, the temp can go as low as 185ºF sometimes(I run a 180ºF thermostat)

My setup is an Evo8 FMIc, stock A/C radiator still installed, mishimoto coolant radiator, stock radiator fans (checked that they work), 180ºF thermostat, 17.5% coolant mixture + 3/4 bottle of watter wetter. I also removed the plastic front airduct to be able to install the fmic.

It seems that when outside temps are hot the car has har times to cool enough to make the fan turn off at iddle. When driving with the A/C on, sometimes the temp can climb at 208ªF. Although the stock temp gauge never has moved more than the middle position.
Water on the reservoir never boils or overflows or lowers it's level. Althoug over time I can see a little bit of what looks like mud on the bottom of the coolant bottle, not much, just a thin layer.

Any ideas?
Is that normal when using a fmic?
Should I rewire the fans to work both at same time instead of only when using A/C?

 

[nek]

Sorry to bring a thread back, but did you fix it? And what do you mean installing a thermostat backwards? I just replaced mine and Id like to make sure I did it right.

 

[4g63-pwr]

Sorry to bring a thread back, but did you fix it? And what do you mean installing a thermostat backwards? I just replaced mine and Id like to make sure I did it right.

I'm not sure who that was directed at, but no, I never fixed the heat issue. The answer to my problem came through a different solution. I parked the car, removed the battery, drained all the gas out and bought a Lexus IS350 to daily drive. Problem solved!

I just came back to this thread to re-grasp where I am at with this damn thing, because I haven't touched the car in a year and I'm about to go to work on it tomorrow. I got tired of screwing with it, obviously. I guess my anger and hate has suceded enough over the last year to motivate me to work on it some more. Plus I miss driving the car and I hate that it's just been sitting.

 

[Misterbeechy]

try removing ## bumper and drive it.. see what happens then

 

[4g63-pwr]

I can't really see that doing much. After thinking back on all of this, I don't think it is airflow related. It did run fine for a month or two with the bumper barely trimmed, then one day it just decided to run hot. Then I did a ton of things to help it and it never made much of a difference. I don't know why I forgot that it ran perfectly fine for a while before it started this crap. I guess being so irritated with the thing, it just slipped right out of my mind. But thinking of that now, it can't possibly be airflow related or it would have started this crap from the first day I installed the FMIC.

I'm putting my bets that either the crank pully/harmonic balancer crapped out. Either that or my new'ish water pump bit the bullet.

 

[tsi87889095]

Do you have a mechanical temp gauge. It could be the stock gauge messing up. I think you have a clog in the motor or the radiator. Or it could be a head gasket. I have a stock radiator and on the hottest day in NC in traffic it runs 195. I would think if it boils that it would be evaporating and there for you would run low on coolant over time. If you have ran water out of your fawcett before for a long time then there could be calcium deposits that build up in the head or radiator that can cause poor flow or blockage. Make sure there is nothing in the fins of the inter cooler or the radiator.

 

[nek]

Well Im stuck in the same boat now. I bought a real oem rad cap, upper n lower hose, 2nd new tstat.
I dont overheat at idle, its when I start moving that I overheat. Almost possitive its my hg. Im gonna take my car to a shop next week to have a leak down test.
I did a compression test and it was 180+ across the board.
Maybe I should go buy that local 93 tt rx7 to fix the problem

 

[JFZERO ECLIPSE]

200 degrees really isn't that bad I think...I would drain some of the coolant/water mix and instead of a crappy 50/50 mix try to get somewhere along the lines of 75/25 or 80/20 mix....Less coolant more water...
Add some water wetter to improve the waters effiency to dissapate heat....The coolant is there to help lube up your cooling system and keep it from freezing...Theres no reason to have a crap load of coolant unless you live in the north and drive round in the winter....otherwise you can add antifreeze to your system then...

For 2g's the ecu enters learn mode at 180*F
The Main passenger side fan kicks on at either 210-211*F The secondary fan kicks on somewhere around 225-226*F

 

[L0ckett]

I've been in this same boat for a good 2 weeks now. I had a brand new head gasket, rad cap, thermostat installed and I'm running at 229 degrees with both fans wired to constantly run. When the car starts to overheat does the coolant boil? If you have tried everything else, including a new head gasket, there is a chance that there could be a crack in the block somewhere, which I think may be my issue. Just some food for thought.

 

[4g63-pwr]

Do you have a mechanical temp gauge. It could be the stock gauge messing up. I think you have a clog in the motor or the radiator. Or it could be a head gasket. I have a stock radiator and on the hottest day in NC in traffic it runs 195. I would think if it boils that it would be evaporating and there for you would run low on coolant over time. If you have ran water out of your fawcett before for a long time then there could be calcium deposits that build up in the head or radiator that can cause poor flow or blockage. Make sure there is nothing in the fins of the inter cooler or the radiator.

Obviously didn't bother to read the thread. I can answer every question via quote

- Mishimoto Aluminum Radiator
- Pure distilled water
- Compression test numbers are solid as well

The coolant sensor and fan relays all work fine.

yes, the gauge is working properly

The radiator is fairly new. It's maybe 6 months old and is spotless inside. The hoses are not collapsing either, they are pressurized as normal

No blockage, no flow problems, no pressure problems, no loss of coolant. Everything is functioning properly.