2G Thermostat and coolant temps

[LiquidX]

You can start by understanding my cooling setup before making comments that would otherwise become known and understood.
http://www.dsmtuners.com/forums/blogs/liquidx/2834-attacking-my-cooling-problem-part-2.html


For a while now, my engine bay has become dreadfully hot. Too hot to touch the valve cover, timing belt, intake manifold, and even my IC pipes. Water has dripped onto the head and it instantly boiled like it would do on the exhaust manifold. The upper coolant hose became rock hard and extremely hot while the lower hose is more pliable and pretty cool to the touch.

My exhaust manifold and external o2 housing are wrapped and so is my upper down pipe.


I came to 2 conclusions, either I have a blockage in my cooling system or my thermostat has become null-and-void. So today I went to do some testing to see if either would help.

I started off by doing a coolant flush using a tee adapter placed in the upper heater core hose and hooked up my garden hose to it. I also completely removed my thermostat prior to doing this. I opened up the radiator drain, turned on the hose and flushed it out until it came out clear. Tightened everything up, got the air out, added a little bit of actual coolant.

On my drive my temps got back up to where they were before and everything is still extremely hot under the bay and my coolant temps were hot enough (no actual data). Very displeased with this. Began to read up on how the system needs some back pressure so I installed a modified thermostat. Basically the spring section is cut out so you still have the plate to install.

Put that in and filled up with 90/10 water/coolant. I now have actual data.

This is with coolant offset on ECMLink v3 at +20*. Fans switched on via link.

Idle with fans on: 165*
Cruise with fans on: 180* max
Cruise with fans off: 190*ish

Coolant offset to 0* and fans switched off via link

Cruise: 210* and fans turn on and temps do not lower

Shut off the car, temps went up as they should, I turned on the fans and monitored my IAT. IAT temperature reached about 133* and the sensor is placed right after the FMIC. I know that the IAT temps will raise as well with a fan blowing on them but that is quite a bit of an increase.


Here is the question, does anyone have any insight to this? Could my water pump not be working as well anymore, could I still have a "clog" somewhere? I'll be taking out my AC condenser sometime in the next couple weeks and I'll try re flushing the system again.

I'm putting in a Mishimoto 143* thermostat Monday and if nothing else works, I'm going to consider putting in a colder fan switch and just bypass the ECU for the fans. I also have to do my timing belt soon and will grab a new water pump as well.


So please, any help would be good.

 

[gofer]

I think there is more to this overheating issue Scott, there almost has to be. My cooling setup on my car is poor man caveman engineering and I have 203* in traffic coolant temps.

- 50/50 mix
- (1) bottle of WaterWetter
- 180* ValuCraft AutoZone special t-stat
- Mishimotor Radiator
- (1) SPAL 12" 1630cfm push fan ziptied on the passenger side of the radiator where the A/C condenser would be.​

I've done no ducting between the back of my FMIC to the radiator either, theres about 3" of space between the two. It pushes air directly into the turbo/j-pipe/exhaust manifold area when it kicks on and you can damn near just grab the j-pipe with a barehand after a 15 minute drive.

 

[LiquidX]

I'll have to pick up some WW and make sure all of the air is out of the system. I'll have to see what else it could be. I am wondering about the water pump still.

 

[phunny]

I think there is more to this overheating issue Scott, there almost has to be. My cooling setup on my car is poor man caveman engineering and I have 203* in traffic coolant temps.

- 50/50 mix
- (1) bottle of WaterWetter
- 180* ValuCraft AutoZone special t-stat
- Mishimotor Radiator
- (1) SPAL 12" 1630cfm push fan ziptied on the passenger side of the radiator where the A/C condenser would be.​

I've done no ducting between the back of my FMIC to the radiator either, theres about 3" of space between the two. It pushes air directly into the turbo/j-pipe/exhaust manifold area when it kicks on and you can damn near just grab the j-pipe with a barehand after a 15 minute drive.

I've been thinking that same thing. Something is failing, and the only thing it can be, besides a HG is his coolant flow.

 

[definitiveno]

Any updates?

 

[LiquidX]

None yet. I cannot afford to do anything with the car any time soon.

 

[GSXSixteenG]

I used Hy-per Lubes Super Co0lant (same as Water Wetter) dropped my temps pretty drastically, I have not done much driving around as the car is off the road. But just a few cruises around the block (with dealer plates) for tuning dropped netted a drop in coolant temps by approximately 10*.

Cooling System Additives - Turbo and High-Tech Performance Magazine

 

[95talongirl]

If you've ruled everything cooling system related out; I think it's time for a leakdown test... You may have a hairline crack in the cylinder head; head gasket problem, or even some warpage.

The white car would run stupid hot on the freeway; (~237ish) After trying to baby it with the fans on all the time, water wetter and such... it still would run hot. Eventually; like a year or so later, it would overheat. I was thinking head gasket or cracked head, but what it ended up being was the block was slightly warped. This means the guy who previous rebuilt this engine did not check it out and slapped it back together.

A healthy car should be able to keep its temperatures between 190-210-ish depending on the tstat and such... if it is having issues, then there is an underlying problem. But this could change depending on how modified the car is, as well... (i.e. bigger turbo.. more heat..) It still should be able to regulate it better that what you are experiencing, tho.

I also agree.. 50/50 is the optimal mixture for coolant to work properly...

 

[LiquidX]

In due time I'll be replacing the MLS HG with a composite gasket, changing the water pump, re doing my timing, adjusting my cams to 0*. I just cant afford any of it right now.

Regardless, with the temps outside now, I don't really see over 190* but that's with the fans coming on at 174* by using the coolant offset feature. I know having a vented hood will help immensely but that's more money to spend and I don't want to chop up a good hood.

 

[Ppayer38]

With my cooling setup my car idles at 184-187 screens cruise and will idle at that for 30mins...
Cruising temps are 178-180 and when I get on it I never see 190 on 100deg days...

Evo rain guard installed in factory hood (huge difference)
Koyo 1g radiator (not as wide as factory 2g radiator and has a huge dent in the bottom haha)
SSAC FMIC
No AC
SPAL 12" 1630 cfm pusher fan mount on passenger side with zip ties
170 t-stat from advance auto
Duct under the car mounted to radiator support to pull air to radiator
Non sealed or ducted system
50/50 mix
1 bottle of water wetter
2gb talon bumper cover
Coated and wrapped tubular manifold and downpipe
IAT's from stock MAF read 5-10deg above ambiant while cruising (no duct work is ran to it just using eBay pipe and kn filter)
Fan comes on at 180 while idling and 190 while cruising VIA ECUFlash

I did find I had a bubble in the thermostat housing that I couldn't get rid of no matter what I did until I replaced the thermostat and flushed the block and radiator then temps dropped right down from 210-220 idle and cruising!

I suggest a leak down test and maybe the duct on the radiator support to pull air directly to the radiator from under the car as cheap fixes for now... If you any good at or have an idea of how to do body work install the Evo rain guard into the factory hood and it helps a ton and is also cheap...

 

[turboglenn]

Man, im' not sure i'd have much helpfull input, but is there anyway you can fit the stock main fan back on the car? I have dealt with tons of overheating issues and that solved most of them.

The other part was solved (and i wrote a tech article about it here on tuners) when i did a flow test and found that the parts store water pump wasn't flowing near the amount of water it needed to be in order to cool properly (i then went to an OEM mitsu pump and it has been perfect since running all stock fans, 180* t-stat and plain 50/50 mix )

Running too cold a t-stat can make you over heat as well, because once it opens the coolant usually doesnt' stop circulating to sit in the radiator long enough to get cooled down to the temp at which the t-stat should close again. The system should actually open and close consistantly after tthe car is up to temp, but if the t-stat is at too cold a temp and the coolant can't stay in the radiator long enough for air to extract heat from it it becomes as bad as running without a t-stat to begin with.

you might want to look at my tech article about testing the flow of the water pump, the parts store reman'ed ones tend to have a different impeller than came in the pump OEM and from what i've found they barely move any thing at idle and then at 2000+ RPM still aren't as effective as OEM

My car using only the cooling system i described above went from fghting the same battle as you to now i can run my AC on a 100* F ambient day and my coolant temps will be ablout 184-186* on the itnerstate, about 190 - 192 in traffic, but no longer do i break 200* and i haven't done any ducting, no foam between condensor and radiator and i have a FMIC blocking cool air from them both. I tried every slim fan there was to be had (that would fit the radiator anyway) and none of them worked like the big stock fan on speed #3. Then with OEM fans on i was doing much better but when i still had issues when i turned the AC on i began searching every where and found an article on testing the pump flow (which is what i do a walkthrough of in the tech article) and once i did that i found my last and final issue, now any overheating is a thing of the past and who would have guessed a new parets store water pump would be to blame.

 

[gofer]

I suggest a leak down test and maybe the duct on the radiator support to pull air directly to the radiator from under the car as cheap fixes for now... If you any good at or have an idea of how to do body work install the Evo rain guard into the factory hood and it helps a ton and is also cheap...

Can you provide some pictures of the duct work and the Evo rain guard fabrication work you've done? I, as well as a few others, would GREATLY appreciate it.

 

[ChillinGST]

I'm having the same type of issue. One way to check your water pump is flowing is to leave the cap off, as if your bleeding the system, and once it gets to operating temps hold the throttle up either by throttle body or someone in the car. You should see the coolant flowing through like a flash flood.

 

[dsmornothing]

Have you ever though maybe your heater core is the problem? The core is used to return the coolant back through the system. If it cant flow fee it obviously backs up and would cause these sort of issues. Also are you running a water cooled turbo?

 

[turboglenn]

Here's a link to the test procedure for the cooling issue i was talkinjg about in my last post, give it a read, mightbe something that will help

http://www.dsmtuners.com/forums/art...ng-cause-thats-rarely-mentioned-how-test.html

 

[Ppayer38]

Can you provide some pictures of the duct work and the Evo rain guard fabrication work you've done? I, as well as a few others, would GREATLY appreciate it.

Rainguard/Hood vent

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Duct or Air dam

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It's the black piece attached to the radiator support with self drilling screws and then ran a piece of tape across the screws/tabs to seal it to the support and it sticks down about 1" above the downpipe so it will not scrape but is plenty below the intercooler to grab air along with being angled forward...

 

[LiquidX]

Thanks for all of the input.

I don't have any tools to perform a leak down test and again, I cannot afford to put money towards the car at this time. I'm still planning on switching out the HG regardless.

Glenn, the only reason I can think of that the OEM fan would be better in my case is it has a shroud that covers half of the radiator. I have more than enough airflow with the fans alone being at 28xx CFM when they come on. As for the thermostat, the same issue was going on with a 170*.

As for checking the water pump, I don't know about the rest of you, but as liquid heats up, it expands. I need to keep a funnel at the inlet so I'm not spilling everywhere. The funnel will fill up about half way when it's at operating temperature. If I remove the fluid from the funnel and shut the car down I'll be low on fluid in the lines.

I also have performed multiple back flushes on the system using a garden hose and the Preston flush kit.

 

[turboglenn]

you don't need a funnel for the method in my tech article, mainly need a couple pieces of hose to hook into your heater core lines and a 2 liter bottle that's empty, it's real simple in the basic terms you'r just splicing the heater core hose and putting the 2 ends into a clear bottle you can see though, and by using the one off the water pipe you can really see how well the pump pulls and pushes water and see if there is a problem with how well it's moving it at id;e and other RPM's.. the really nice thing about this setup is it's able to run full temps and circulate in the bottle where you can burp every last bit of air out of the system as well.. Believe me there's a few advantages to doing this way over just pullin gthe cap off and watching the circulation at the t-stat (as well as this method being better for getting the last bit of qair out of the system) if it hadn't been for this check i would probably still be overheating

As for the fan, I think most of it is to do with thr shrouding, but the fan really moves a lot of air in comparison to the slims i had on there when i would just have my hand behind it feeling how well it was blowing the OEM unit was the most kick ass one i had, i went through spal, slim-line and many other aftermarket fans before just giving up on them and going back to OEM and i'm glad i did go back because i have full reliability in my cooling system with air conditioning and a front mount and the nebraska summers are HOT

 

[LiquidX]

you don't need a funnel for the method in my tech article, mainly need a couple pieces of hose to hook into your heater core lines and a 2 liter bottle that's empty, it's real simple in the basic terms you'r just splicing the heater core hose and putting the 2 ends into a clear bottle you can see though, and by using the one off the water pipe you can really see how well the pump pulls and pushes water and see if there is a problem with how well it's moving it at id;e and other RPM's.. the really nice thing about this setup is it's able to run full temps and circulate in the bottle where you can burp every last bit of air out of the system as well.. Believe me there's a few advantages to doing this way over just pullin gthe cap off and watching the circulation at the t-stat (as well as this method being better for getting the last bit of qair out of the system) if it hadn't been for this check i would probably still be overheating

You you have a picture or video of this procedure. I understand the cutting part, but what bottle are you using and I assume it's staying there permanently. How are you guaranteeing that all of the air is out of the system along with being sure you are able to get it all out?

 

[olmytsi]

I've been running a 160 degree thermostat, only the stock passenger side fan, on all the time, and my car runs below operating temp most of the time and I live in HOT Miami...I know every car is different but it shows that these cars can run COOL without all those mods ppl do...and I have a HUGE FMIC...I did remove the a/c and the condensor.

 

[turboglenn]

You you have a picture or video of this procedure. I understand the cutting part, but what bottle are you using and I assume it's staying there permanently. How are you guaranteeing that all of the air is out of the system along with being sure you are able to get it all out?

I'm sorry i don't have video, the bottle is only in place for the test and the test is only done while stationary in the driveway. I used a clear empty 2 liter pepsi bottle, threw it away after the test was done.

The best thing to do is get a double end connector so you can split the heater core hose from the water pipe (using this line allows you to get air bubbles that can't be burped out through the t-stat housing)

The 2 lines you get from splitting the line from the back of the water pipe are the ones you'll be putting into the bottle. You can use another double end connector and some extra hose to make the line longer and easier to route out of the engine bay and into the empty 2 liter bottle. I guess as far as knowing 100% that every last bit of air is out of the system is impossible just as it is with burping it at the t-stat housing.

But this way will help you get more of it than you can get from the t-stat area. Once you've finished and are about to put everything back to normal having the lines with the but connector ready to go so you can hook them up fast without loosing much coolant is helpfull to keep from getting any more air back into the system

 

[Car Cannibal]

I've got a lot of experience with cooling issues from old hot rods to 80's EFI to our Talons, I'd start here.

1) Compression Test
2) NEW Radiator Cap (unless old ones tests 100%)
3) 80/20 Coolant is just enough for high temp boiling and water cools better
4) RMI is a much better additive vs Water Wetter and RMI eats away corrosion
5) Add timing to your idle and cruise, 22 to 46 (total) will do wonders to EGT and cooling
6) Dual fans with a shroud are key but you seem to have this already
7) Any venting of under hood heat is a bonus

I have two cars with WAY more cubes that stay under 170 degrees in the Summer heat, the above works.

 

[ZenkaiRacerDsM]

Whats RMI?

 

[Artago]

Whats RMI?

Let me google that for you

 

[LambdaJoker]

Here's a link to the test procedure for the cooling issue i was talkinjg about in my last post, give it a read, mightbe something that will help

http://www.dsmtuners.com/forums/art...ng-cause-thats-rarely-mentioned-how-test.html

Some pics or a video would be helpful to understand how this test is done. I'm confused at the part that says, "you need to take BOTH heater core hoses off and run them outside the car with some extension tubing from autozone.."
If you take both heater hoses off, wouldn't you get one great big air bubble in the heater core since no water is running to it?
As far as the rainguard mod, that looks nice. I might look into doing that to my extra hood I have. A DIY tech article for this would be great.
Do any parts stores sell rmi25? I dont think I've ever come across it at a parts store.

 

[97gst_spyder]

Any updates on your coolant temp issues? I'm having the same issues. 210+ at idle/city. 2 OEM fans, factory solid copper radiator, 180* thermostat, 50/50 mix, and ducted just like yours.