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2.0 Redline overheating

7K views 56 replies 10 participants last post by  Need4Speed2 
#1 ·
Beginning of March I had my car overheat and when I got it home after a few hours. I had replaced the thermostat again and bled the system out several times. So I then replaced the water pump thinking it was it and the old one looked really bad so glad I did it. After putting everything back together, I poured the coolant in and used a pump to pump it through to get a lot of the air out. After all of that, I turned the car on everything running fine and went to drive around. The car is still running a bit hot and heater is still blowing cold and the fans highest speed didn’t turn on until 223 to 225 degrees. I ran the car again after I let it cool down and now the temperature got to 232 degrees. I ran the car one last time after a few hours later and I took off on the car to see how it would do on higher speed and after I did it once the car popped after letting off through the exhaust and it blew a little bit of white smoke. Keep in mind that the car was dirty sooo I cleaned it out and it was probably that when the catalytic converters was off the car when I did the water pump. Well after I did that the cars Coolant reservoir tank over filled like it over heated and when I look at the temperature it is still at 205 - 210 degrees. The temperature doesn’t build up fast like when I first over heated the very first time, so it is taking its time like it suppose to but still overheating. Can someone help me with this to see what I am looking at next? Thank you in advance.
 
#3 ·
205-210 is pretty common. A thermostat isn't rocket science...in fact it's very primative by today's technology (truly am surprised we haven't gone electronic on these yet!!). My car always ran 200....replaced my tstat and now it runs 175-180 and very rarely get above 200, but my fan comes on at 195 because of my tune. Many here though are consistent at 200+. Keep in mind that your car will always run 5-10 degrees warmer with the heater on as well. The theory is that the temp sensor is close to the heater box. But my theory is the car retards the timing a bit to build up heat when you switch on the heater.
 
#4 ·
I am not aware of any connection between the HVAC system and the ECM except for the full-throttle AC cutoff, and have never seen any kind of mention of any timing changes to generate more heat. Neither of my cars consistently indicate a higher temperature with the heat "on", but do vary between about 180 and 210 during the normal course of driving, especially when power demands and speeds change significantly.
 
#5 ·
Mine has always varied by 8-10 degrees with heat on....even in 10 degree weather. My fan comes on full at 198 per my tune. In the winter with the heat running, my fan will run continuously as the heat easily climbs to 200-205 and is steady at that point until I shut off the heat. Then it falls to 190-195 in 10 degree weather and if I do the DFC in gear, it'll get as cool as 175, but only if the call for heat is off, otherwise it stays above the 190 range in DFC. In 90 degree weather my car won't go above 198 unless my AC is on. But I don't drive mine in the winter anymore.
 
#6 ·
Okay guys that hat only happened the last time and I am mentioning this because the reservoir tank overfilled like it was over heating but before I ran it that time it was over heating up to 232 degrees and the heater still blowing cold instead of hot, I have already replaced the water pump and thermostat and aired out the bubbles from the system. What should I do?
 
#7 ·
In general I would say that if the heater is blowing cold when the engine is hot, you are still airlocked, although you could have a heater control problem. The combination of 232 degrees and no heat from the heater points very strongly toward air. There have been reports of people going through the purge process several times before getting the air out of the system.
 
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#9 ·
If the t-stat is good and the fan controller is working, then just get the vacuum fill system for the coolant. It's about $75 and saves you ripping out your hair, cutting into the system, and from all the half-functional bleeding tricks. $75 and ten minutes and you're done.
 
#10 ·
This is what I used when I did the turbo upgrade on my car and a buddy's. Zero hassle. Zero problems.
 
#12 ·
Comes with directions. It's pretty simple to use, though you do need compressed air to create the vacuum.

It removes all the air from the coolant system, then you close the valve from the vacuum pump and open one to a coolant line. The vacuum draws the coolant in and because there is no air in the system, there can't be an air pocket left: The system is quickly filled with coolant and only coolant.
 
#14 ·
I did not use the OEM AC Delco but that one I replaced last year and it worked well until the car overheated again this year and replaced the thermostat to be on the safe side and it was still overheating sooo decided to replace the water pump and good thing I did cause it was bad but didn't fix the issue. I may still have a lot of air pockets in the system cause it doesn't heat up like it suppose to when it is overheating but it still overheats if that makes sense.
 
#15 · (Edited)
The reason I mention it is because DDM Dave has chimed in before and has stated that he has changed many thermostats but the only one that has been reliable is the OEM stat. Many times he's put one in from Advanced Auto Parts and ended up in the end changing it again for the OEM one. He now only uses the OEM stat.

With the hole you drilled in the thermostat when you installed it, the air should be easy to get out.
 
#20 ·
OK, I got my "water wetter" and I am going to drain the system, and refill with only water and "water wetter." I dont need antifreeze here and the "water wetter" has the additives I need. Sooooo where is the lowest point in the system where I can drain it to get the most of the Dexcool out?
 
#21 ·
I have a 2009 Saturn Sky 2.0L Redline. My car started to overheat at the end of February this year. I had replaced the thermostat that I replaced last year thinking it was it and aired out the system and thought it was fixed and overheated again but up to 234 degrees. The Heater blows cold and overheats, I was told it was a water pump so replaced that but I have not replaced the thermostat(it's not the oem one) at all and aired out the system after adding coolant. The car still overheats with heater blowing cold and when I drive the car it overflows the overflow tank. I had a friend do a compression test after and the compression is fine. When we running the car in the garage, he lifted the overflow tank and it was overfilling when I was doing about 1500 rpms and looks like coolant is getting into the overflow like it has a lot of airbubbles, the fan does come on at the right time. I don't know what it is and need help figuring it out. DDMWorks told to me to check the if the fan is blowing cold or hot to check between the belts and fan and it is blowing cold which he said that it should be that the thermostat isn't opening cause of all of the air in the system or could be a bad thermostat. I hope y'all can help me on this. Thank you!
 
#25 ·
Then you either aren't using the correct nipple with the tool at the coolant reservoir and it's allowing air in there, or you have a leak in the system. I did two Big Wheel swaps last year and used that tool to refill coolant in both cars with zero problems in the process or result.
 
#34 ·
A stuck-shut thermostat will cause overheating, but will not prevent heat from the heater. A stuck open thermostat will hinder the engine from getting to temperature and severely reduce heat from the heater in cold weather. Overheating and no heat from the heater is generally and air lock (bubble) or a non-functional water pump, ie: something that keeps water from circulating.

A compression test or (better) a cylinder leak-down test will give you a good idea about whether you have a blown head gasket.
 
#35 ·
Even if the car is running fine? Also, I had already replaced the Water Pump and replaced the Thermostat wayyy before the Water Pump. What do I use for a Cylinder leak-down test? How will I know where it is leaking from? I've done a compression test and it's perfect.
 
#39 ·
If the coolant system can't be evacuated using the vacuum tool, there is an air leak in it somewhere. It's never going to work correctly as long as that's the case. No matter what you do it will end up vapor locked, the heater will blow cold, and the car will overheat.
 
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