2G running hot at idle STUMPED

[cumpersgsx]

I'm having trouble getting temps down to normal. This all started last season and i still haven't been able to figure out this nightmare. Temp at idle will reach 210*, the fans turn on and are pushing/pulling correctly. The only way to get temps down is to turn the heat on full blast along with the rad fans going. That gets the temps down to 200* at best. I've searched the threads for ideas and can't seem to figure it out. My values are being monitored by dsmlink. I've tried keeping the fans turned on and never seem to change the temp. The only thing I can think of is to get another thermostat and double check it with boiling water and possibly drill a hole in it.

things i've tried:
bleeding(burping) the system
verified there was no heat soak from the ex mani
new full size aluminum rad
new rad cap
new thermostat x2
new sensors
new fluid
new water pump
new head gasket
adding fans
switched to a half rad

 

[renovatdkitchen]

You could try yet another rad cap if everything fails.

There's a guy on my local forum who bought a new rad cap to try to fix his overheating issue, turns out the new rad cap he bought was defective and after replacing it again, his temps were fine.

Have you taken it to a shop with a coolant system tester?
Are you running very lean at idle?

 

[cumpersgsx]

my afr is spot on at idle 14.4-14.7. I am going to grab a coolant system pressure tester from work tomorrow. The last thing I want to do is take it to a shop and have them go thru all the steps I've already done. My labor is cheap .

 

[gst-turbo]

My temp were at 220 all the time after fmic and i changed my thermost to stant 14077 and flushed my system good. Put 50/50 coolant/antifreeze and a bottle of water wetter and my temps are at 190 with ac full blast at idle and on freeway they go to 185

 

[cumpersgsx]

Looks like I'll try another cap and stat. I'll have an update later today.

 

[renovatdkitchen]

I had a stant thermostat in my 2g and I never overheated with an aluminum rad, two slim fans and a FMIC. Used distilled water and redline water wetter for coolant.

 

[NHerron]

How is the airflow to the fans/radiator. There should be no gaps on any sides or it's just recirculating the hot air. Try to perfectly funnel the air to each core, if there is a lack-of ducting between a FMIC and radiator it's just recirculating hot air..

 

[Jakes 93GSX]

My brother had a OEM radiator in his car and put a brand new aluminium radiator in it and it started over heating. Did basicly the same steps as you and still over heated. Swapped back to OEM radiator and it fixed it.
See if u have a fellow dsmer that will let u swap a known OEM radiator into the car and see if it fixes it.

 

[renovatdkitchen]

Huh. What brand? I've had great luck with a fluidlyne and a mishimoto rad.

 

[ACWgraphics]

try removing the a/c condenser, it is a huge restriction for air flow to the radiator.

 

[cumpersgsx]

Ac condenser is removed already.

Bought the stat. Put it in boiling water and it works. Worked at 180ish . Now to install.

 

[cumpersgsx]

Gst-turbo!!! I owe you a case of beer and a handshake. I used a stant thermostat 14077 and got a new cap and I can control my idle temp now!

 

[ceedawg]

Displaced about 32oz of antifreeze, put in entire bottle of water wetter,added water to replace some of the antifreeze that I took out then I put in 185 degree stat and new pressure relief cap car will still run up 220 to a first time 228 degrees at idle then will go to 182 when driving.

Only stays below 200degrees at idle when I set the ecm link to keep both fans full on all the time.

Other issue:

Not sure if I have a defective 1g (cars a 2g)coolant temp sensor or not but the fan cuts on and off erratically and the temp while logging on the link the numbers run erratically too. This does not happen all the time but it will more often tan not.
Put fans full on, link #'s are stable as are both fans with the car running cool at 185 to 190 degrees at idle and when driving.

Go figure!
Have ETS 4" fmic
Have no ducting
Have condenser
Aftermarket fans pull push
Fluidyne radiator

Any suggestions?

 

[NHerron]

No ducting, added core and questionable fans...

What is your fan setup. Brand, spec, amps, mods, etc

 

[ceedawg]

No ducting, added core and questionable fans...

What is your fan setup. Brand, spec, amps, mods, etc

Can't confirm the fan make. I know the puller fan has curved blades and the pusher fan has straight blades.
Motor is built on top of the fore mentioned mods. But not sure what that would have to do with suggestions.

Displaced about 32oz of antifreeze, put in entire bottle of water wetter,added water to replace some of the antifreeze that I took out then I put in 185 degree stat and new pressure relief cap car will still run up 220 to a first time 228 degrees at idle then will go to 182 when driving.

Only stays below 200degrees at idle when I set the ecm link to keep both fans full on all the time.

Other issue:

Not sure if I have a defective 1g (cars a 2g)coolant temp sensor or not but the fan cuts on and off erratically and the temp while logging on the link the numbers run erratically too. This does not happen all the time but it will more often tan not.
Put fans full on, link #'s are stable as are both fans with the car running cool at 185 to 190 degrees at idle and when driving.

Go figure!
Have ETS 4" fmic
Have no ducting
Have condenser
Aftermarket fans pull push
Fluidyne radiator

Any suggestions?

No ducting, added core and questionable fans...

What is your fan setup. Brand, spec, amps, mods, etc

Not sure of the fan brand but mods are listed in my post other than built 2.0l. Push pull setup with 2 fans.these were installed early 2k

 

[NHerron]

Mods I meant pertaining to cooling fans. Like any cutting to fit, weird wiring, idk.

Anyway your setup could use some intervention IMO. Since they are aftermarket (possibly ebay?) fans I would check em out... Can you check amp draw? Rule thumb via Spal is 10amps per 1000cfm. I don't know stock fan cfm, but I know their amp draw, wrote down somewhere...

And ducting is a big deal. Otherwise it recirculates hot air, ya know, path of least resistance blah blah blah. Imagine a giant air tunnel. Now throw your radiator down there. Air totally bypasses it. Now make a giant sealed wall but punch out a spot for the rad to fit snug. All airflow must pass through rad now. Simple I know but seriously, people don't get it sometimes. A piece of paper should easily stick to the furthest-from-fan core.

Push pull setup, all fans spinning in correct direction in relation to airflow? I know you said early 2k, so I'm sure that's not a problem...

Here's a good link
http://www.hotrod.com/how-to/engine/ccrp-0707-high-performance-cooling-system/

 

[ceedawg]

Yes Im going to do the ducting for sure,there was no cutting to fit or weird wiring done it is just weird that the fan that normally functions will work erratically and when logging you see the coolant temp log show the #'s moving erratically. Anywho I'm going to go with a 1g coolant sensor, have some spal fans on order, Ducting and see how it goes. Thanks for the link going to read it now.

 

[oren hughbanks]

X2 on the cheap eBay fans. All they are good for is a desk fan. Had similar issues, constantly changed out cheap fans, radiator caps, thermostats etc. Finally got my hands on a OEM passenger side fan, ditched the ac condenser, and problem solved. Rarely see over 200, usually sits at 195

 

[NHerron]

Someone correct me here but

The fans on a 1g are controlled directly from the sensor and relays, no computer involved. On a 2g however the computer does everything- watches temps via two wire sensor and commands relays on/off. Maybe the 2g computer doesn't like the 1g sensor. Plus 1g sensor is located in rad correct? 2g is thermostat housing. Two wire sensor is for computer, one wire sensor- directly to dash gauge and if you have CALI emissions, a two nipple vacuum switch... Something to do with cancer I'm sure.

 

[GST Jeremy]

I had the same issue on my 2g did the stat put in a 16psi rad cap still nothing bought a dual core with slim fans and full shroud still ran hot... I had air in my system in the end I had to bleed it out for almost a whole day. jack the front end way up in the air and get a coolant bleeder

 

[NHerron]

+1 air.

Engine cold, take rad cap off then runer' till just about boiling. Pressure test afterwards and pressure check cap, still amazes me new caps can be off 2psi+...

To rule out core airflow issues, idle car until starts overheat, then spray down rad with garden hose etc.. Off top my head. There's better diagnoses I'm sure.

How exactly is 1g temp sensor and 2g car wired, what's your setup? The sensors could be different ohm vs temp spec so maybe you're not even overheating...

 

[NHerron]

Another thing, I believe the thermostat has a little air bleed device that must face a certain way... Along with correct side up. Some people drill a hole instead...

 

[99bluegst]

Let the car idle on till you rich 203f*, check the lower hose you thermostat should be open by now, if the lower pipe is not hot it mean water is not flowing throw the radiator, revving up the engine when you'll notice the temp dropping cause the water pump is forcing more water throw the hole system, check you radiator I bet is clod

 

[keltalon]

Huh. What brand? I've had great luck with a fluidlyne and a mishimoto rad.

Good question! I have found that a lot of the ebay aluminum radiators are single core units that don't cool worth a flip. You have to get a good dual or triple core aluminum unit to effectively do the job cooling at idle. Also a lot of people crap out on getting a good cooling slim fan, ebay units will not get the job done they are made of cheap plastic that when exposed to any type of heat, the fan blades flattens out. You when looking at them you have to get one that move a good volume of air to be able to push or pull through a dual or triple core radiator. I been down this road before and ended up getting a good triple core radiator and mounting two high velocity fan purchased from summit racing and have never looked back despite the temperature rising over 100 degree sometime here in ga. What type of fans are you running? Do you know the core count of the radiator? Very good suggestion stated above switch back to stock radiator and stock fans to see if this helps.

 

[ceedawg]

Spal fans came in. Going to order a 2g coolant sensor. Gotta make time to install them will be a challenge with having to remove my dual wastegate setup to take it out. Oh yeah and my fmic so I can get access to the fan on the front of the condenser. Before putting it all back I will seal between the radiator condenser and fmic.

The hottest I have seen the car go from stop and go traffic is 227degrees. Driving it goes down to 185-190 degrees. I doubt if there is an issue with the radiator or the antifreeze flow.. Likely suspects wold be fans ,or something with this 1g sensor and how it is controlling the fan. When I program the fans to stay on both then come on and she stays at 195 to 200 at idle and in stop and go traffic. The coolant temp number' s also run steady as does the fan when logging. Weird.