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.

 

[95fwdtsi18psi]

You shouldn't have problems with heat with your setup. You may have something else wrong. Try checking your thermostat, you could try running some water wetter or something and see if your temp drops.

 

[KGB Pilot125]

could try turning the fans off at speed and see if that helps they could be a restriction. one other thing I know it will sound stupid but check to make sure that both fans are pulling and they are not hooked up backwards.

 

[eeeewidner]

Some food for thought. Run a log, see if you are running lean......As stated above. You shouldn't have any cooling issues....

 

[95fwdtsi18psi]

could try turning the fans off at speed and see if that helps they could be a restriction. one other thing I know it will sound stupid but check to make sure that both fans are pulling and they are not hooked up backwards.

I made that mistake on my Camaro when I added my slims! Lol I felt so stupid putting the fans on backwards!

 

[bpe121212]

I had the same problem as you and tried all that you have tried to remedy the heat issue with no success! I finally tried the setrab oil cooler radiator upgrade and that did the trick!

I am running a Garrett BB 50 trim and use the car for daily driving and weekend road racing and the heat is now not a problem.

I have recently sent in my FP exhaust mani, O2 housing, turbo hot side, and down pipe to HPC for coating and plan on installing everything next weekend. I will let you know if this helps in any way.

Best of luck to you


PE

 

[4g63-pwr]

You shouldn't have problems with heat with your setup. You may have something else wrong. Try checking your thermostat, you could try running some water wetter or something and see if your temp drops.

Thermostat is fine. It is about 5 days old and I even tested it before installing

could try turning the fans off at speed and see if that helps they could be a restriction. one other thing I know it will sound stupid but check to make sure that both fans are pulling and they are not hooked up backwards.

Turning the fans off makes it run hotter. Even turning just one fan off makes a fairly significant difference

Some food for thought. Run a log, see if you are running lean......As stated above. You shouldn't have any cooling issues....

I don't have a datalogging capability on this car. It shouldn't be running lean though, it's virtually stock aside from simple bolt-ons.


I'm out of ideas here. I'm about to the point of taking the FMIC out. Removing the A/C isn't really an option in Houston. I just don't get why it's running so hot. My GSX never has cooling issues even at open track days in the summer heat, but I can't make this car just drive down the freeway to get me to work.

 

[95fwdtsi18psi]

Is your water pump working properly, it could be flowing a lower amount then what is should. Check everything related to your cooling, sensors/fuses and all. I know people that bolt up a big FMIC and do nothing and have no problems with cooling. You should have ice on your motor with your setup!

 

[4g63-pwr]

Is your water pump working properly, it could be flowing a lower amount then what is should. Check everything related to your cooling, sensors/fuses and all. I know people that bolt up a big FMIC and do nothing and have no problems with cooling. You should have ice on your motor with your setup!

The water pump was replaced along with the timing belt about 9 months ago and shows no signs of leaking. The coolant sensor and fan relays all work fine.

I am about to add some water wetter and fabricate some extra ducting and see if that helps. Not sure what else I can do.

 

[4g63-pwr]

I improved my design on my air diverter and the sheet metal enclosing the radiator to make it more efficient and added some Redline Water Wetter. No luck, still starts to run hot even on my 4 mile trip to work

 

[93blacktsi]

my 1g with a big fmic does this on the highway after about 1hr still cant get it to stop

 

[4g63-pwr]

my 1g with a big fmic does this on the highway after about 1hr still cant get it to stop

I would love it if my car would last an hour. I can get in my GST in the morning, start it for the first time, drive away immediately with it ice cold with both fans on and the coolant temperature gauge will start to creep up after about 2 miles.

It's highly irritating considering the amount of people who run the same or even bigger intercoolers with less cooling efforts and no problems. My GSX doesn't run warm at all no matter what I do to it and it has a Spearco core that's about the same size. I just can't figure out why my GST is being a pain.

The GSX has a Fluidyne radiator, FAL fan setup and a Spearco core. Those parts can't those parts really be that much better than the PR core, Mishimoto Radiator and Mishimoto fans that are on the GST. But yet the GSX has twice the HP and gets driven ten times harder and the temps never move.

 

[UnsafeAtAnySpd]

I'm not sure I saw this mentioned, but are you sure your gauge is working properly?

 

[4g63-pwr]

Hey, my GST fits your username. ^ It is "UnSafeAtAnySpeed"

Anyway, yes, the gauge is working properly.

 

[4g63-pwr]

I guess I'm just going to have to buy a nice side-mount and ditch the FMIC. It's the only thing left I can think of to make it run cool (aside from removing the a/c which isn't going to happen since it's daily driver in South Texas).

That's not really what I wanted to do though since it will look retarded with my bumper trimmed for a FMIC. I guess I'll just have to get me a new bumper eventually too. I've thrown away a bit of money (and WAY too much time) trying to make this core work. I'm about to just chalk it up as a loss I suppose. I love the fact that I essentially bought an intercooler, just to ruin my bumper. Now I still need an intercooler and now a new bumper.

 

[fergulus]

I'm one of those people that installed a big FMIC and had absolutely no cooling issues (besides the bad thermostat that opened at 220) that sprang up because of it.

Have you ever turned your fans on and put your hand in front of the FMIC to test for airflow THROUGH the intercooler? I don't have proof (because I have only owned one front mount), but I think that heating issues might arrise because certain intercooler's fins dont allow for enough air to go through. The stock fans should be able to suck enough air through the intercooler to hold up a sheet of paper.

I'm a native of Houston temporarily relocated by the Army to Georgia, so I understand your pain. That A/C just can't get gutted down there.

 

[4g63-pwr]

No, I haven't done that but I'm sure it's moving plenty of air. These fans I have now sound like a hurricane under my hood. I can hear them moving a ton of air even from inside the car. They do keep the car cooler than the stock fans did. Everything I've done so far has helped to some degree (no pun intended ), but it's still not enough. The temperature gauge will just go up almost 3/4 of the way (stock gauge) and stay there. It's doesn't get any hotter, but definitely not ideal.

 

[Lofer]

This may sound stupid, but are you sure you dont have any air trapped your coolant system. Ive never seen it on a dsm, but if air is trapped in your coolant system it will never stop overheating til you get the air out. I would try bleeding your coolant system, just run it for awhile with the cap off and massage your coolant hoses a little, easier if you have a spill-free funnel for radiators.

 

[95fwdtsi18psi]

This may sound stupid, but are you sure you dont have any air trapped your coolant system. Ive never seen it on a dsm, but if air is trapped in your coolant system it will never stop overheating til you get the air out. I would try bleeding your coolant system, just run it for awhile with the cap off and massage your coolant hoses a little, easier if you have a spill-free funnel for radiators.

It's hard for trapped air to stay trapped in our cooling systems.

 

[lacroixdp]

Try propping up the rear of your hood. Use some washers to raise the rear of it up... it will help some heat escape from your engine bay.

 

[fergulus]

Even easier than adding washers is to just pull up the rubber gasket that the back of the hood sits on. It wont make the hood look broken by having the ass end forced up. Did you replace/upgrade everything else before or after the front mount install?

 

[Lofer]

It's hard for trapped air to stay trapped in our cooling systems.

Yeah i didnt think these did that but i used to be into vw's and have countless hours getting air out of my coolant system. sry.

 

[4g63-pwr]

This may sound stupid, but are you sure you dont have any air trapped your coolant system.

I completelety flushed and bled the system when I switched to pure distilled water w/ Redline Water Wetter

Even easier than adding washers is to just pull up the rubber gasket that the back of the hood sits on. It wont make the hood look broken by having the ass end forced up. Did you replace/upgrade everything else before or after the front mount install?

I already tried removing that seal.

Some of these things have been upgraded happened before I installed it. I already had the aluminum radiator, new cap, new exhaust gaskets and the heat shield. I also did the timing belt and water pump before installing it. I've since switched to lower temp thermostat, Mishimoto fan and shroud, fabbed the air diverter, removed the rear hood seal, enclosed the radiator, DPDT fan override switch and switched coolant.

It was initially undriveable. Now after doing all of that, I can drive it, but I don't want to because it still runs on the hot side.

 

[knochgoon24]

Even easier than adding washers is to just pull up the rubber gasket that the back of the hood sits on. It wont make the hood look broken by having the ass end forced up.

I already tried removing that seal.

While that theory works on some cars, it doesn't on ours. The back edge of the hood is a high pressure zone. That's one reason why the vents are there for your car's HVAC.

By lifting the hood, you can actually increase the air pressure in the engine bay, leading to even more cooling problems.

Have you tried ducting yet? Several members on here have had success with it. I'm going to give it a try sometime this week. Maybe even this evening. The sheet metal is sitting in my room now.

 

[4g63-pwr]

Have you tried ducting yet?

Yes, it's been mentioned in about 4 of my posts. I have an air diverter that catches air passing underneath the car and forces it up behind the FMIC into the radiator. I also used sheetmetal to enclose the areas between the intercooler and radiator to keep air going through it instead of around it.