With the car running, take off the radiator car and squeeze the upper radiator hose until all bubbles are out then put more fluid and repeat.

When does it overheat? At idle, on the highway, or both? What fans do you have (size, brand, say which is pushing/pulling), are they shrouded, and where are they placed on the radiator?

what are your compression numbers looking like then you can rule out any head gasket issues. just check it once more wouldn't hurt.

Car over heats at idle. New waterpump kept cruising temp down. I did burb system. Mishimoto is shroud and their fans I do believe 12 inch. That pulls and 10 pushes. Right now its a distilled water btw. I will do compression check. It has maybe 10k on forged internals. Also I used oem headgasket with arp headstuds torqued to 90 foot pounds

You shouldn't have air in the system if your thermostat is in correctly or if the head gasket didn't blow. The thermostat has a jiggle pin that should be installed at 12 o'clock position . You might want to do a leak down test to rule out the head gasket . Another thing is with this new radiator are you using the stock main fan or aftermarket . Also are you running a stock exhaust manifold or a header . The fan should come on at 212 and go off at 200 . I had temps rise when i installed an external waste gate .To fix that i wired the fan to go on at high speed , installed a colder thermostat and wrapped the external wast gate.

• Why did you change your head gasket?
• When it was changed, were the head and block checked for flatness?
• Do you have an fmic installed?
• If you have an fmic installed, is the area between the radiator and fmic sealed/ducted?
• Have you tried using the stock primary fan?

Like others have said, you may want to check compression and leak down test. Pressure testing the cooling system would be beneficial as well.

I hope running water only is very temporary as coolant lubricates the system, prevents corrosion, prevents electrolysis, and raises boiling temps.

I was running the 1G Mishimoto dual 12" shrouded fan setup at one time. I had issues with it causing the car to overheat both at idle and at high speed. I found that the crappy shroud design allowed the air to stagnate, rather than move smoothly through the front air dam and out of the fan cutouts. This is one of the reasons the stock puller fan works so well, because of its extremely efficient shroud design.

Here's what I used to do: Go drive you car and get it nice and hot (at least to operating temp). Then, park it in your driveway, and let it idle. Monitor the temperature and wait for the car to start overheating. When you see the temp start to creep up, pop the hood and leave it open with the car running. At that point, your fans should be able to pull the temp back down eventually. I used this as a test to gauge how well my fans were performing. If the fans could pull the temp back down with the hood open, I knew the heat soak combined with the fans not moving enough air was causing the overheat. With the Mishimoto shroud, the fans wouldn't pull the temp down even with the hood open. I determined the whole fan setup was an issue at that point, and I removed it.

I feel your struggle. I've been fighting with my Galant to get it to cool at idle for a long time. I just recently figured out a fan setup that will get the job done. I posted some info regarding my current setup here: http://www.dsmtuners.com/threads/efficient-electric-fan-setup.496791/#post-153541631

The radiator and shroud are both mishimoto. I got stant thermostat 180 degree. I didn't see the jiggle pin. I have fp manifold with a blanket on it. I have bottom intercooler piping wrapped with relector tape. I didn't drive it much since replacing waterpump. I thought I fixed the issue I was seeing 206 but when I did a pull saw 216 but cooled back down. Drove it home and let it idle and seen it creep to 216. External dump is recirculated.

Reason I did headgasket was I lifted the head and started to over heat. I checked everything with a piece of glass to make sure it was true. This is why I started to double check other peoples work because the headstuds weren't torqued to spec or in sequence.
There is coolant in the system just not that much. I flushed the radiator and all my lines to make sure not clogged. I will do leak down test later. I have 3 12inch mishimoto fans and 10 inch mishimoto fan.
Even when the car is at idle with hood open and both fans running on full car will not cool down.
No ducting yet but car is not over hearing while driving. I am going to make duct work.
Car has fmic and had no issues before or I never noticed car overheating with stock radiator

How do you have 4 fans set up? If you have fans in front of other fans, they are just blocking airflow. You should only need 2 fans, set up in the most efficient configuration your setup will allow (typically, both pulling).

No I don't have 4 at once. Just saying I have 4 of them. 12 inch mishimoto is in the shroud and 1 10 is pushing on the ac condenser.

Ahh, gotcha. You might want to try removing the shroud. It may or may not fix your issue.

What was your fan setup like while you were running the stock radiator?

Just 1 12 inch fan. That's what I did but I started to over heat so I bought the shroud to see if that will fix the issue

If you have room for the stock primary fan, try that as a single fan instead of all the others.

Talon64 said:

No I don't have 4 at once. Just saying I have 4 of them. 12 inch mishimoto is in the shroud and 1 10 is pushing on the ac condenser.

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I think the shrouds are not actually tested and proven. I've never needed shrouds and I run Oreillys slim fans with a big VR front mount and condenser. I suggest taking it off and see what happens like others have suggested.

I have a stant thermostat and it did have a jiggle pin . I would take the thermostat back out and check . My wast gate is also recirculated and creates a lot of heat so that's why i wrapped it . I also mentioned about the fans which are 2 speeds . What i did was to wire it up so it runs on high speed only .

Thermostat stant 14077 has no jiggle pin. Waiting for push clips for the fan install

Put the stock fan back in. It is better than that aftermarket unit.

I was gonna say the stock cooling fan on these cars are awesome and the shroud forces all the air across the radiator. The factory plastic air duct in the front of the car also is designed very well to force the air across the radiator while moving.

Also the ethylene glycol raises the boiling point of the coolant, while the glycol does not allow the heat to be extracted. So running pure water will allow better heat extraction the fact that the water may be boiling might be part of your problem. I would mix coolant according to your geographic location and add redline water wetter. Water wetter allows the coolant at a molecular level to get closer to the radiator allowing better heat extraction.

OK adding some coolant and double checked thermostat. Driving car was 190ish. Today was only 80 degrees. At idle coolant temperature was coming up. Put both fans on and coolant stayed at 216. I do believe fan shroud doesn't work for me. Will change over to stock or just 12 inch slim fan

There is a reason why Mitsubishi engineers put that jiggle pin there . I would get a thermostat that has a jiggle pin . Back in the 1980s chrysler was building there 4 cylinder engines without that pin and we used to have overheating problems especially on first start up . To solve the problem we used to drill a small hole on the thermostat and face it straight up and that would solve the problem. Now all are thermostats have that pin to bleed off any air .

If you are gonna run after market fans. i have found good way to help if you are running a fmic. i put them on front of rad and push.

Just make sure you get a good fan. Most of the Ebay-like fans (Mishimoto included) don't move nearly enough air. You'd be best off with the stock puller, or a good fan like a FAL or SPAL.

My conquest would overheat in traffic really bad. Thru trial and error I found that pure distilled water didn't work because the water boiled, running without a thermostat over circulated the coolant and wouldn't allow the heat to be extracted. To solve the problem I mixed coolant 50/50 for my area, added water wetter, and drilled an 1/8" hole in the thermostat.