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.

 

[pur97tsifwd]

A few things you could check is make sure you dont have alot of bugs leaves stuff like that in your radiator and condensor. Make sure you fins on both are not all bent up. If you are on stock radiator it could be clogged up from age of coolant and if it is i dont know if water house pressure would be enough to blow it out. You could try making you a better shroud since you have a fmic to help your radiator with airflow.

I think your best option is get a new radiator like a mishimoto and make you a better shroud setup.

Also make sure you use distilled water when mixing if you dont tap water will destroy freeze plugs and cause corrosion.

 

[pur97tsifwd]

Also you could get you one of those guns that tell you the heat of where it is aimed and shoot in alot of different spots on the radiator this could help you find where it might be clogged.

 

[LiquidX]

Duct work is basically 100% sealed and it's a Mishimoto radiator I have and it's clean. With the fans on, a thick piece of cardboard can be sucked up from the bumper lip and stick to the FMIC.

 

[gofer]

A 90/10 (water/coolant) mix is actually bad, do a 50/50 and put in a bottle of Redline WaterWetter too.

Putting in a colder fan switch is going to create more work than anything else Scott, I don't think that would be any different than changing your coolant offset 20* in Link. I'm not familiar with running a t-stat with a cut spring, what advantage does that serve over the typical 180* t-stat right out of the box?

You could also try getting an actual Mitsubishi brand t-stat from the stealership, its a bit more expensive but its not made in a sweat shop. MD315301

Leak down test?

 

[LiquidX]

Corey, the cut thermostat is basically just cutting the center section out so the springs are removed. All you are left with is just the outside ring.

I know water pulls more heat than the coolant however coolant provides lubrication and increases the boiling point. So I don't know. I'll try the WW which I've used in the past after input the new tstat in.

 

[9!'clipseDOHC]

I don't really think a 143* thermostat would help at all. If you are already overheating (and your thermostat is working properly), a lower thermostat won't lower your temps, regardless of when it opens it will still overheat. I would go with the OEM 180* like Corey suggested.

I switched from a 50/50 mix to 75/25 with a bottle of water wetter and it helped lower my temps a lot. I can't say it was all the mixture though because I did several things all at once. I think another large part was the ducting (which you've already done) and just bleeding the system very well. Make sure you have the heat on (to get the air out of the heater core and heater hoses) and keep squeezing the radiator hoses to get all the air out.

 

[talon187]

you gave me a good idea to mount a fan on the front of my new rad for my mirage thanks. you could run a 165 t stat advanced auto sells them i have to get a new one myself. im wondering how im going to do with a 3 row honda half sized with a shroud and moto ran. how big is the fan on the firewall side? whats that push ? are you running one or two on that side? i know its alittle much but you could run 3 fans

 

[LiquidX]

Nate I see where tou are coming from but the only thing keeping temps down is having the fans on at all times. The whole turn the heat on doesn't do anything for out car as the coolant travels to the heater core constantly. Turning the heat on just turns the blower motor on to allow the air to go through the vents.

From what I've now gathered, I'm getting knock from temperatures at or over 190* which is why I need lower coolant temperatures.

 

[9!'clipseDOHC]

I hadn't heard that about the DSM heater core. It seemed to help mine.

For a 2g the ECU pulls 1* of timing if the coolant temps reach 206* and 2* at 224*. It will also pull 1* with IAT's over 100*, 2* over 132*, and 3* over 185*.

For comparison, 1gs don't pull any timing based on coolant temps but they pull 1* at IAT's over 132* and 3* at temps over 185*.

 

[gofer]

Interesting I've never of that technique/modification to the t-stat before Scott, I've always just drilled a hole in the t-stat creating a weep hole.

 

[dsmpat95]

I'm going to say your thermostat is null and void.

 

[LiquidX]

People, please read before posting. I appreciate the help but it doest help when what you ask has already been talked about.

Corey, is there some other way to flush the system, mainly the block side?

 

[talon187]

this may seem stupid but would a vented hood help? it would let all the heat go up and out of the engine bay keeping things cooler wouldnt it ?

 

[LiquidX]

Yes it would help but I currently do not have the funds for one. It is on my list for things to get. I've been contemplating cutting the stock hood.

 

[NightRider97]

I'm going to keep an eye on this thread because my car has been doing the same exact thing lately. Only with my car I think I've let it get hot enough to over pressurize the radiator cap and it blows half or more of the coolant out on the ground causing it to over heat more.
I didn't notice it doing this until, very oddly, after I installed a Fluidyne radiator and cleaned out the AC condenser. First weekend cruise after that it over heated to 237* with less than 2 gallons of water left in the system. I replaced my crappy parts store 195* Tstat with a OEM 180* one but its still over heating by several degrees. Not to mention, turn the AC on and within a minute its going over 215*.
My fans are locked on same as yours, and my intake temps idle at 133*. It just blows my mind. I'm almost wondering if my head gasket is blown, or for some reason no water is going into the cylinder head.

 

[Sandman817]

check your upper and lower radiator lines to make sure your thermostat is working properly. Also, make sure that you do not have air trapped in your cooling system, this will cause your engine to run hotter. a 50/50 mix with water wetter and a 10* cooler thermostat should work out great.

 

[gofer]

Corey, is there some other way to flush the system, mainly the block side?

For some reason I remember there being a block drain for the coolant system, problem is I'm 99% sure its on the backside of the motor just under the intake manifold and damn near un-accessible.

In the past I just pulled the t-stat and opened the butterfly valve on the bottom of the radiator, then shoved a garden hose in there and let it push water through the system until it came out clear.

You may also try replacing your radiator cap, if that things weak you'll notice strange overheating issues too.

 

[LiquidX]

Ah ok, that was my only other thought for pushing water through the system. I'll give it a try later just through the hoses first fit any potential blockage and then see what the block does.

The thermostat is newer and it's a 1.1 bar from Autozone. I have noticed that I am getting a lot of hot heat from the vents at the full temperature range from the selector knob. Cold and hot are the same heat and it doesn't make a difference if I select outside air or cabin circulation.

On a side note Corey, all of that knock I discussed with you before is pretty much non existent at temperature under 180*. I also just flushed my oil as well for a just in case. I'm starting to consider taking out the MLS gasket and switching to a composite for another "just in case". The coolant doesn't bubble or smell like combustion gasses but there isn't much left to check.

 

[talon187]

I know im in the same boat with the hood deal. im thinking of geting another stock one and cutting it myself i think i can pick one up for like $50

 

[gofer]

After a casual drive around the city and then let it sit, does the upper radiator hose still feel hard after its cooled? I ask because I blew my HG awhile back and it wasn't overheating but my turbo was also pressurizing the coolant system, I popped my heater core because of it.

 

[LiquidX]

Ill have to check that after today. I'll be putting in the new thermostat and re flushing the system. Hopefully my new fan comes in today so I'll be able to pull out the condenser as well.


Edit:
No, the upper pipe stays as pliable as the lower one right now with the lower temperature. When it gets up to "operating" temps of 200, it feels rock hard and everything in the bay is scorching hot. Wire loom melting into puddles off of the power steering pump.

Even at the cooler temps, my timing belt is almost untouchable.

 

[LiquidX]

Just installed the 143* tstat, removed evaperater, 12" 1230cfm pusher fan, 100% sealed ducting (rad to FMIC, bumper to FMIC). I'll get some updates tomorrow on temps

 

[phunny]

Hey, since we're both working on setting up the best possible cooling setup I have some thoughts on yours, especially the 9" fan.

Here's my thinking; we all know that air is going to take the path of least resistance right. I'm thinking the with duct work the fans are going to pull the engine air through the radiator instead of pulling through the thick fmic and then it will use that air to actually heat up or at the very least not cool very efficiently. Thoughts?

Check this out, just found it http://www.youtube.com/watch?v=uDTSdYE3AJQ

 

[LiquidX]

Without a shroud setup, I can slightly see that occurring. I think it would be more with a puller fan than a pusher as the air getting sucked in could very well come in from an area outside of the blown air and kinda cycle around.

On my first setup I put a barrier strip of foam between the condenser and radiator straight down the middle. My theory was that without it, air being pulled in from the puller would actually grab air from the pusher on the other side and become less effective. Blocking it would prevent that from happening.

It may work better for you as well as you still have your condenser and a 12 fan would only have some small corners to get sucked in from. You have to remember that there is a lot of turbulence from the blown air that would hinder engine bay air siphoning.

I could also see that having a closed stock style hood would improve those odds as well since hot rises and doesn't like to travel low.

In my opinion, the chances of this theory you have lessens when you have air flow on both halves effectively pushing air away.