I installed a new fan shroud and the Mishimoto aluminum radiator, flushed the coolant and replaced it with Mishimoto's Chill coolant. Before this the car ran around 194 idle and slightly hotter while driving. Pretty much always around 194 F. On my test drive after the install the car got up to 221 F which is the hottest I ever seen it so I shut it down, waited 20 mins and drove back. Why do you think the coolant temp is getting so hot? It should be around 194.

Another thing is when the fan does come on, you should feel air blowing between the fans and the engine blow, meaning that its pulling air threw the radiator, instead of pushing air threw the radiator and air coming out of the grill correct? Any way to force the fans to come on or change the temp at which they come on? Could a sensor have been disconnected or something perhaps?


Solved: Read Post #8

 

i know in my SS/SC if i have my AC on the car will maintain 180f (180 thermostat) but if my ac is off, at idle it will get to be around 210-220 and the fan doesnt come on til almost 220.

are you driving it around at 221? or just sitting still? while moving- the air hitting the radiator should cool it down close to your thermostat temp. if youre driving and its that high- might have air in the system still.

the only way to change when the fans come on is to get a reflash with custom fan settings, or wire up a manual fan. but i think youve got nothing to worry about unless it gets hotter than that.

 

Why is it running way hotter than usual? It was always 194F now its 20F hotter. Doesn't make any since.

 

all i can think if is there might be air in the system. also you changed coolant- could not work as well as the standard coolant. let it run idle with the ac on full, see what the temps level out at.

the couple of times i flushed my coolant, it took a couple days for all the bubbles to get out doing standard driving

 

Alright so I just went and replaced the thermostat (180F), the old one wasn't opening up at all. Still have the same issue afterwards. The hose going from the block to the radiator (top left) gets hot, but the radiator and the (middle right) hose stay cool. I'm in the process of seeing what it would be like to run the car without the thermostat in place.

 

Air in the system.

 

put in dexcool like the manual says

 

I noticed that feeling the coolant entrance hose (top left of the radiator) to the radiator was hot while the radiator itself and the coolant exit hose (middle right of the radiator) were cold.

So what I ended up doing was removing the thermostat, coolant reservoir cap and turned the heat on low, ran the vehicle for a few mins to remove the air that was in the system. Put the thermostat back in and bled the system again and it was working like new.

In case you like pictures, this is the thermostat housing without the thermostat.


The thermostat itself.


The thermostat in the housing.


Also I had to purchase a new thermostat because the original one would no longer open when it reached its 180 degree mark.

 

Ah, classic air bubbles.

The tstat needs to be open for it to bleed, which is why some people drill a hole it in to help bleeding.

I don't understand why most new cars have the coolant reservoir set up such that the overflow tube is open to air in the reservoir rather than using a tube to the coolant, but whatever. That also makes it difficult to bleed.

Something that helps is to squeeze the rad lines. That'll push the bubbles out of the lines and rad and into the reservoir.

The method that works best for me is start the car with the cap OFF, heater ON. Run to >180°F, watch coolant level and fill accordingly. Once the level doesn't change, squeeze upper line (WITH GLOVES), watch coolant level and fill accordingly. Watch more. Fill and close reservoir (while hot). Check it at least daily for a few days. Done.

Don't let the system cool off before closing the reservoir. You'll end up sucking in another annoying air bubble.

This isn't necessarily for OP because looks like you got yours solved

Also, I have an LNF so I don't need to remove the upper rad line and fill through it but it's not a bad idea anyways.

 

When I flushed my LNF I filled the system as best as I could with new coolant. pulled off the overflow line, pointed the left half into a bucket, and pressurized the other side which runs to the overflow tank with air just below where the cap started screaming. Worked great for filling.

Plugged the overflow line back in and let it idle with the cap open, kept it filled to the line. Ran it around the block and just kept an eye on the coolant level every drive and kept topping it up. No new coolant needed after day 1.

 

Thanks for picking up our radiator! We are a bit late in helping diagnose the issue you were having. Sounds like the thermostat replacement and air purge did the trick. Air entry in the system is quite common when replacing cooling system components.

Enjoy the radiator!

Thanks
-John

 

Yep everything has been running great. Thanks!

 

I have had the mother of all problems with coolant issues on my 09 SS/TC, should somehow make the Guinness book of records, posted several threads on it and have fought this most of last year, car wants to run warmer in cooler weather and temp is seldom stable, climbing from 214-230 after several miles then back to around 214, this is usually in outside temps are in the 20's and 30's. Not so bad when temps are in the 50's. Changed radiator, thermostat with hole, purged everyway imaginable, finally took to dealership they said water pump which LDK had new pump on it, long story short that didn't fix it, they refunded money. Car temp was usually 194-198 until LNF block cracked, started having these problems after low coolant which I assumed air in system, never got any better after new engine and parts, dealership even did vac and fill several times.

 

You said you got a new engine after all that happened? I'm no expert on cooling systems, but do you have tune at all? Also, my eureka moment was when the car was above the 180 degree thermostat point and I felt the enter and exit coolant tubes and noticed the exit tube and radiator was cold.

 

My problem started after LNF cracked, 6K previous miles no problem,194-198, I am sure I got air in my system when coolant tank ran low but wasn't to worried since engine was trash. Car does have a tune, could not contact previous owner but 25-26 lbs boost, runs great. My lower radiator hose is cold likewise. I still think air in system but I have tried and GM has tried with no luck, what is strange is the colder the outside air temp the more unstable the engine temps are with higher peaks. Didn't mean to hijack your thread.

 

Haha no problem. My issue is solved with this thread anyway. The only thing that I can really think of is doing what I did a few posts back and maybe checking to see if there is something blocking the entrance to the radiator if no coolant is flowing. I'm assuming the entrance tube is hot after the car has been running for a while.