Cooler water with FMIC Project

[Tarantula]

I have read just about every thread on people having hotter running engines due to putting a big FMIC in front of the radiator. The FMIC blocks precious airflow to the radiator causing the coolant temps to rise. I have tried the wiring the dual fans together via a switch and it did help but with the 180 thermostat, temps would only fall to 206 at idle and maybe 199 on a cool day or night. On hotter days driving on the freeway (Basically 100% of my time is spent on freeways here in San Diego)would cause heat to rise. So it was not a solution. So I lowered the thermostat temp to 170. Was better but now during cruise on a cool day with fans running full time temps would fall to 183 and that would take my car out of closed loop and fuel mileage suffered. So thats not a solution. Than I wired a 3rd fan as a pusher. No solution. I then cut off 8 rows of fins from the condensor to try to make air flow easier on the bottom part of the radiator. No solution. . Found a way to make both Main and AC fans to run on high speed with no solution. All helped but nothing really changed the highest temp seen. (222-226) It just prolonged it. Than I found out why nothing worked.
The ECU on the 2G has total control of the fans. It has programed startups for the fans. After looking deep into them heres what I found.
At idle: Main fan starts 210-212 off at 199
Cruising under 40mph fan works like at idle
Over 40 fan turns on at 222 off at 217 This mode turned on both fans (Which is what I was seeing on the freeways and the big flaw in the ECU program)
At idle temps at 222 turns both fans on till 217 than ac fan shuts off while main keeps on till 199.
All of this shows that airflow is the cause. So I decided to experiment. I monitored temps. When they reached 190 (Close loop starts at 185) i waited till it hit 200. I turned on the fans. Both wired for high speed. when temps fell to 190 I shut them off. For the first time ever the car so far for the past 2 weeks I have been doing this has not reached or over 210, even up hills doing 70. It seems that if you start off cool, it remains cool. Go over 212 and its hard to go back down.
Now for the project. I want to tap and drill the water neck (Where the radiator cap is) for a thermoswitch to turn on fans when temps reach 200 and shut off when temps fall to 190. The plan involves the switch grounding the relay therfore turning on fans. As long as the temps don't fall to 190 fans will remain on after turning on at 200. This solves the closed loop operation issue with just leaving them running. Mind you to get this working so far I have to use a 170 thermostat...NOT stock 180. I also bought a spal fan to replace the ac fan to provide more airflow. What i'm doing is simulating the airflow you would normally get when the fmic was not there, but with it being automatic. This is something the ECU does not provide while moving. Also I am not interfering with the ecu and the CTS
The problem is finding a switch small enough to put in that small pipe without it restricting coolant flow too much. So far found a VW thermoswitch which turns on at 198 and shuts off at 189 but its too big at 3/4 diameter but does not hinder flow since its flat(Autozone SW533) Water neck is 1 1/4". That would be a huge hole. Than I found Napa FS158 turns on at 199 off at 189 but $46 I'm going to keep searching and post my results. Till then any suggestions that might help would be great.

 

[MitsuBoost]

hmm, i just mounted my front mount about a month ago, according to my OEM gauge my water temp use to point at exactly 1/2 without FMIC, and now with the FMIC at about 95 degree weather the gauge peaks out at 5/8 in 25mph traffic, but it drops slightly to about 9/16 when i hop on the fwy going above 60mph... The difference is so slight that i think its safe to ignore it, i also didnt notice any difference in fuel economy. My cooling system is all OEM btw. Oh and those gauge readings i mentioned are with my AC running the whole time

 

[Tarantula]

I have been running my fans for two weeks to simulate what I'm going to be doing with this project and amAzingly my fuel economy went up. I have 650's with HP 255 Walbro pump rewired. My fuel trims have always been 0% / 0%. (2G) Before the project I would get 17MPG. About 237miles to get from really full to really E (Below the E when light is steady on) Since the project I get 20MPG 279miles. All I do is turn on the fans to cool at 200F and shut them off at 190F. I already decided on going with the VW switch since its the most perfect. I plan on drilling and tapping the water neck for the 3/4 threads.

Also don't trust the guage. When my guage rose over the center it was approaching 222F and above. (Verified by the logger) That guage is in no way accurate. Remember that on freeway traffic above 40mph your fans are not doing squat. (At least for 2G's where the ECU have total control over the fans) The fans will not turn on until 224F and shut off at 217F and cycle between those temps. In traffic I do not have any issues. The fans do their job perfectly. I can be in the heaviest traffic in 101F weather (Which I have been) and perfect control over temps. Its just at speeds.

 

[slugsgomoo]

I think the biggest thing that would help you at this point is some thin aluminum sheeting, and some weatherstripping. Most heating issues can be lessened greatly simply by forcing the air that goes through the front mount to actually go through the radiator instead of under the car.

ducting is one of the best, easiest and cheapest things to try- and i've never seen an instance where it hasn't made a pretty noticeable difference.

 

[ltho98]

Eliminating the water coolant through the turbo and running an external oil cooler solved all my FMIC overheating issues.. in NEW MEXICO heat.

 

[StarDiamond]

The reason why most of us 2g guys have the over heating problems is when u look at the water passages in the block they are diffrent then a 1g. Most 1g 6 bolt blocks don't go over 190 daily drivers. Before my front mount i would see temps in the 215 range and settling in the 200 range. In my opinion that is still really hot only way to solve this. Come up with a air damper the force air through the rad. Since i attend a engineering school this has become my project. My first model is being made now out of alum. The final model i want to go with carbon. I will keep you guys posted on my results. The main killer here though is still the water passages in the 7 bolt block and the 6 bolt block are def diffrent and cause some of the heating issue.

 

[Tarantula]

I have researched this issue much more thoroughly than any of your answers can provide solutions. I am not overheating due to any problems. I don't have any problems with cooling my engine. What my problem is is airflow! In stop and go, ok it cycles between 213-199. 101 weather no problem. Parking lots or a million stop lights, a-ok. Drive over 50 and the fans shut off. I have a Green led providing me with the info on the fans operation and it clearly shows that the fans are not running when over 50 and under 222F. When it does hit 222F the fans turn on but shut off at 217. My car cools off really easily under 50 like as in 45 miles per hour. Non of your solutions will work. Thats because I have already figured it out with my research. I have done it all. Flushed 6 times filled up with all combos of Distilled water and the glycol. Ran water wetter . All does nothing over 50. Like I said my car does not have an issue with overheating.
I have been doing my airflow project now for almost 3 weeks and it works perfectly.Check this out and you will learn a few things that I learned and which has helped me see the real problem.
http://www.gmtips.com/3rd-degree/dox/tips/cool/overheat-1.htm Read all the sections and you will see what I'm talking about.

My situation has changed. When the fans come on it cools down so fast. When they are off it heats up slowly but surely. An overheating problem would be in most cases like a switch. I never boil my water. I don't have exhaust fumes in my coolant. No leaks, new cap, new thermo, new water pump, new watter wetter new coolant new sensors new senders new hoses. And finally a 2 year old all metal radiator that has been flushed over 8 times (Counting the first year I flushed it twice)

Just see it. When you have no airflow you will heat up. And one more thing.
Here are some facts. The 2G the ECU totally controls the fans
The 1Gs theres a thermoswitch.
2G's fans only turn on at the time I have stated above in my first post.
1G's fan turns on everytime the temp reaches the Thermoswitchs temp rating. Theres a huge difference, see it? With 1G the fan always provide airflow by force. The 2G the ECU is programed to think that at 50+ mph theres enough airflow.
That is why 1G do not have issues as much.
So Hakcenter try it. Hook up a fan led and you will see that your fan will turn on whether at idle, stop and go or at speeds over 50mph. The thermoswitch for the 1G is 190. My project is with a thermoswitch set at 198F. Your thermo is located on the bottom of the radiator where the coolant has cooled a little bit. Mine will be place right when the coolant exits the head before it enters the Radiator. I guess thats why the 1G's thermo is set lower in temps. cause the 190 water temp that the thermo is set to stop cooling is right when it enters the block. Closed loop starts at 185F
I will be getting the same thing. I got the idea from a combinations of things and one of them being from the First generation DSM's

 

[Maglin]

Ok if your problem is the ECU controling your Fans just take it out of the loop. Get a new fan relay and wiring kit. It comes is a new thermo switch but you can just get one for your radiator that comes on at say 195 and shuts off at like 185. They are very easy to install. I've done it to a few cars where the damn fan relay is toast and can no longer be purchased cause they don't make that relay anymore. I know I could just rewire and make any relay work but I actually prefer the self sustained fan relay. With the kit comes a thermoswitch that you push through the radiator. I wouldn't install that on my car that way but for any stock car who cares.

Anyway that's probably your best bet to get the ECU out of the fans way. But the other reply are correct. If you encased the FMIC/Condensor/Radiator so that all the air flows from one to the other then your problem would also be corrected. You really don't want to have your fans running at speed cause it will hurt your gas miliage and thus that is the reason past 50 MPH they don't turn on cause stock their is enough air flowing through their not to need them. I took my AC out even though I live in the Desert. I'm going to install a new R134 system with a R134 condensor and conpressor in the future. Then I'm going to duct it so it won't overheat. Also changing over to pusher fans on your radiator not only helps IC efficiency but they flow more as pushers then pullers. I have a 14" Ziger that flows 2500 CFM. I never overheat even on days where it's 110* outside, and I have a hugh FMIC. Although that fan pulls so much amperage that when it kicks on the alternator puts enough load on the engine to drop the idle down 250-300 rpm for a second.

 

[Tarantula]

Ok if your problem is the ECU controling your Fans just take it out of the loop. Get a new fan relay and wiring kit. It comes is a new thermo switch but you can just get one for your radiator that comes on at say 195 and shuts off at like 185. They are very easy to install. I've done it to a few cars where the damn fan relay is toast and can no longer be purchased cause they don't make that relay anymore. I know I could just rewire and make any relay work but I actually prefer the self sustained fan relay. With the kit comes a thermoswitch that you push through the radiator. I wouldn't install that on my car that way but for any stock car who cares.

Anyway that's probably your best bet to get the ECU out of the fans way. But the other reply are correct. If you encased the FMIC/Condensor/Radiator so that all the air flows from one to the other then your problem would also be corrected. You really don't want to have your fans running at speed cause it will hurt your gas miliage and thus that is the reason past 50 MPH they don't turn on cause stock their is enough air flowing through their not to need them. I took my AC out even though I live in the Desert. I'm going to install a new R134 system with a R134 condensor and conpressor in the future. Then I'm going to duct it so it won't overheat. Also changing over to pusher fans on your radiator not only helps IC efficiency but they flow more as pushers then pullers. I have a 14" Ziger that flows 2500 CFM. I never overheat even on days where it's 110* outside, and I have a hugh FMIC. Although that fan pulls so much amperage that when it kicks on the alternator puts enough load on the engine to drop the idle down 250-300 rpm for a second.

Wrong. Ok 1. Those setups you describe are not as accurate as having a thermoswitch actually touching the water, which my setup does. Although it does work its a bit tacky in my opinion. I don't want to be sticking nothing into the radiator fins and having a bunch of wires all over the place and on top of that more relays. Why add more when there are 5 fan relays that comes stock on the 2G. I can just ground one of them and wala! instant turning on of fans. Plus 185 is right at the starting of closed loop. Fuel economy can be sacrificed a tiny bit because it can go to 183F right when the fan shuts off. My Thermo shuts down at 180-190F That way when temps do fall a little bit it will still be in closed loop cause it would fall to 186F
2. I have done everything including remake a shroud to replace the original plastic one surrounding the radiator. I made the new one out of sheet metal. Air is going through the intercooler and to the radiator alright. But you are forgetting one thing. Velocity. It will be lost going through a 3" thick FMIC. Try blowing through a screen that covers the windows and put 2 more screens in front on the first one and space them 1" apart. Put your hand behind the 3rd screen and blow. The velocity hitting the first screen will not be the same speed as when it comes through the 3rd screen. Same thing applied here.
3. I have a 1400cfm pusher in addition to having the stock 2G stepper fans run off its high speed rather than the normal low speed. (Look up Stock fan has a high speed? thread) Won't do me any good even if I had a 1,000,000 cfm fan pulling due to the ECU shutting them off after 50+ mph. I don't overheat. Never do when the fans cycle like they are meant to. So it just proves to be airflow as the cause. With slow airflow hitting the last of the 3 cores its obvious temps are going to rise. By program the ecu turns on the fans at 222F and shuts them off at 217F over 50mph. I get to 222F fan turns on and within a minute temps drop to 217 and it cycles at those temps. A million red lights, at idle, in traffic at 101F weather and i can have as low as 199F and never exceeding 213F. All these conditions obviously exist below 45mph. Airflow!!!
And 4. Closed loop operation starts or kicks in at 185. During closed loop the ECU calculates fuel trims for the best fuel economy while keeping it as stioch as possible for emision purposes. My projects permist me to have the fuel economy of closed loop shutting off at 189F and turning on at 199F. Fuel economy is not sacrificed. In fact Fuel economy has increased sinced I started simulating the fans cycle manually via a switch inside the car and me monitoring the logger for accurate temps.

 

[crunchymilk]

Just for perspective I run the slowboy2g fmic kit with the stock cooling everything, and I've never overheated once. It's always at 1/2 or lower, the logs from dsmlink match up. This is in Texas heat by the way. (100+)

Guys who have overheating problems after fmic install may want to look into alternative reasons for this.

 

[Tarantula]

Please no more suggestions as I have done practically all of them. I have clearly stated that I'm no amatuer in this cooling situation. I have done my homework for several months and all the answers that ou can give I already found either from other members or on the internet or in my own car doing research. This project does not sacrifice anything and its near perfect. With all mods, another mod needs to take place. Well I'm modding the cooling system. Read that link I provided as it has mucho information. I have made my decision on this project based on research on many different cas down to the 80's and even cars of today. The ECU is programed this way on the 2G for a reason. Manufacturers set the fans to go off at 212F for emissions reasons and if you look into the even newer cars of today you will see that the temps at which the fans kick on is getting hotter. Again for Emissions. Who need to worry about emissions if we are trying to extract performance. Cooler engines provide a bit more performance than a really hot one not to mention a cooler engine usually last longer. With no mods, the car is set to handle almost all situations from the manufacturer. I modded my car. Now I have to change the way my car is designed to work from the factory to benefit me with my modifications. This is one of them and like I have stated. I have been doing this exclusively every day for the past 3 weeks. I drive my car ALL day everyday. I do 280 miles every 4 days and have driven my car in all temperatures and road conditions (ie up hills down hills) Practically 98% of all the miles I put on my car is freeway miles in excess of 70-90 miles per hour. The other 2% in stop and go redlights, parking lots etc. Everyones driving habits are different and driving your car to work will not heat the car as much. When I drive my car I drive it with enough time to heat everything, like transmission, engine bay parts, wires hoses, motor mounts etc etc etc. My work involves me driving the car from client to client all day. The longest my car rest during the eight hour work day is 4 hours. Read the link. You will see alot of things that make sense. And read all sections.
http://www.gmtips.com/3rd-degree/dox/tips/cool/overheat-1.htm

Also with dsmlink you can have it so the fans run even over 50mph. I don't have dsmlink so I have my ecu controlling the situation. Half on the guage could mean up to 219-222F dependant on car and sender used and/or condition of sending unit. I have a new one. Remember what I posted. At 222F the stock cooling system is programed to turn on fans and shut off at 217. That is enough to keep the needle at half mark. So half mark don't mean squat.
over 85F intake temps you lose one degree timing.
Over 206F coolant temps you lose 1 degree timing.

This project helps keep all that timing. Also one more thing. This project is emission check friendly. When I need to do my emisions check, I just turn off the ground to the thermoswitch and the stock fans will operate as programed. No modifications to the stock system. Even if you don't have an issue with higher coolant temps, this will prove to gain longetivity of the engine cause heat kills the engines lifespan and will give you performance due to a cooler running engine.
I will provide details of the project as I finish it. I also have more info in this THREAD

 

[Budget90GST]

How is it that you come on the forum and ask for more suggestions yet you keep telling people that respond that you have everything figured out?

Then you talked about not wanting more clutter in you engine compartment yet you're re-engineering a cooling system that seems to work for everybody else...by adding more "stuff" to it.

I'll give you my opinion on the matter although you'll probably tell me that you've figured it out already. If you know that your FMIC is blocking your radiator airflow, then why not try another FMIC....maybe the one you have is too restrictive to begin with. I'm running a cheap JohnyRacecar FMIC that I paid $215 and I don't have an "airflow" problem although I know my temperature went up a bit compared to stock (but that's to be expected with any FMIC). My point is that everybody telling you their experience with a FMIC is just trying to help. Just like I hope I am.

Finally, if you believe that your solution is the perfect one for your application, then by all means "go for it". Just post the results later so other people can benefit from it later instead of asking for more suggestions...

My 0.02 cent...

 

[Tarantula]

I guess thats why people are suggestion. But its a misunderstanding. When I asked for suggestions it was for suggestions on my project. Not suggestions on figuring out why 'm running hotter. Sorry if everyone was misleaded.
I never said anything about more clutter. I said I thought it was tacky putting something into the fins of the radiator. And why put more relays when the stock system has 5. It was more of a that thermo kit is not necessary. I am adding one thing. One thermoswitch in the engine bay and one wire which is aready there. I previously added a manual switch in the car but thats not the engine bay. And I wanted a steath look. I also have to worry about Smog check here in CA and we all know that here in CA it is the strictest of all united states. This idea keeps Mr. EPA happy while keeping me and my engine happy.

I'm sorry if everyone thought I wanted help. i though maybe one person might have a nice idea to help me with my current idea. For example. In another forum one person understood what I asked when I said suggestion. They said I could just put a pipe with the thermoswitch in the center of the radiator hose so that I don't hack up the water neck. That way if I needed to try another switch I won't have to buy another water neck. The radiator hose is cheaper to replace than the water neck. Now that was a great suggestion.
I thank all you guys for your interest in reading my idea and the suggestions so far. Just like my "Cooler air with SMIC project" I just wanted to help myself as well as others overcome a common situation. Just like the first project its just a simple modification.