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Coolant temp

7K views 31 replies 13 participants last post by  Need4Speed2 
#1 ·
Hey guys. Just wanna be sure I'm not missing something and be sure. Yes I have checked as many old threads as I care to. Here it is. Water pump replaced 8,000 miles ago. No leaks. Normally the sky 2.4 runs 190° to 200°> Live in Florida. Today was about 97 in the sun and in traffic, AC on, stop and go it climbs to 219 over time. I stop at a store for 7 min, get in and start it and it reads 225° which quickly dropped to about 210° when I got moving. My mechanic is certified and has worked at several dealerships for a long time. He says that General motors built these cars to run between 200 and 230 And I should not worry about this. What are your thoughts?
 
#3 ·
I appreciate the come back. I have a decent amount invested in this car to bring it up to snuff after years of apparent neglect and heaven knows what so, if nothing else I want to protect my investment. Its my DD and I love it and being able to tap into the knowledge here is priceless. Thank you.
 
#4 ·
Today was about 97 in the sun and in traffic, AC on, stop and go it climbs to 219 over time. I stop at a store for 7 min, get in and start it and it reads 225° which quickly dropped to about 210° when I got moving. My mechanic is certified and has worked at several dealerships for a long time. He says that General motors built these cars to run between 200 and 230 And I should not worry about this.
Totally normal and I believe him. The reason you see that spike up to 225 is because where the sensor is in the car. It's in the thermostat housing at the back of the engine. When you park the car, excess heat moves from the engine to the coolant tube and thermostat housing which runs directly under the exhaust manifold to the rear of the engine. Since the car isn't moving, the temp at the coolant temp sensor rises because it can't remove the heat from that location since it is no longer circulating.

When you get back in the car, the coolant starts moving again and now the temp sensor will see the coolant that had been hanging out in the radiator, getting heat removed from it, and the temp drops down to a temp lower than what you had seen while driving.

I am no sure it is quite that high, but the fan does not run at full speed until the temp reaches 220. I have seen temperatures right at 219 in SoCal when temps are nearing the 100 degree area. I would not worry about it much sir.
When we were going up S6 at Palomar last year with the San Diego group, I don't think one car was running below 230...15 cars, NA and Turbo, mid 90s and no one had their AC on going up that steep grade with some gusto. LOL
 
#5 ·
Mine fluctuates quite a lot too it seems.......I'm not sure that reading is accurate (on mine) ....it dances QUICKLY between 190 to 197 to 205, back to 190, etc.
As long as it does not stay over 200 for an extended period I will not worry.
 
#6 ·
At freeway speeds or a good clip it hangs about 190-195. Now this is in summer in Florida. When I get into stop and go and its 90° to 95° with AC going it will crawl up to 113-120. If I cut the AC it drops but thats brutal in the heat. Not tryin to be a fraid-e-cat but I would not want to burn anything or ruin something from overheating. I have never had a car that I have had to worry about that but the Sky. Is the car just built that cheap or wrong or just odd?
 
#8 ·
Analog. So It was not as accurate. I don't mean to make a bigger deal out of this than it is. This is one of the coolest cars I have ever owned and I would like to keep it for many years. I was reading some of the earlier posts talking about engine coolant temperature and it seemed they were running between 190 and 205. Some of the guys say there's car very rarely gets above 205 maybe 210. Probably being overcautious but that is where I am right now.
 
#10 · (Edited)
Nah... you're ok there MB. Yes it is a concern when we as owners see the temp rise, that odd noise or shake from our cars.
Better to be safe than sorry, or in some cases left stranded on the road side, hood up, steam rising from your engine bay.
No cell phone service, not a soul on the road for miles, and in your case there MB, the odd Gator strolling across the roadway 20 yards from where your stranded. Sucks to be you!

While it is true our cars do tend to run, a little hotter than some/most cars past or present is still can be a shock to see the temp gauge rise. The expense for high temps, from the WP replacement, thermostat, radiator, fluid, hoses $$$ to other issues that
could cause.. motor damage.

For me, seeing it rise to 214 in the DIC came as a shock. However when considering the outside temps, the up hill grade I was on, after about 3 minute idle down/cool down at the top with no air flow, it was back to normal at 195.
Any change to the fan speed, and or the climate control, one or two clicks results in 2 degree temp change in the DIC sometimes in my car. Your results may vary.

The day I bought my Sky was hot 97 degrees, humidity off the charts. So while driving the 100 miles to get the Sky in my HHR, sitting in early morning traffic, the temp rose to 217. Sound familiar? GM designed the coolant/radiator in the HHR had me worry some. In the Sky on the return trip home,... top up, A/C going the temp during the hwy cruise home, no temp increase. When I got home.. things were different. 205..207..209 wth? 2 minutes later 195 sitting still. No air flow is no air flow, and imo our cars needs the air flow.

In the Turbo version, it creates more heat in the engine bay with little to no relief with exhaust for this heat to remove it's self.
The hood on our cars has those fake vents, which could help this out. Some of our owners have " altered " these vents to let heat
out of the engine bay. The fake side vents again here could be used for air flow through the engine bay. They designed it to be there, IF the owner wanted this later on, but during production the cost for making these vents work was not in the cards or price. Even in the bottom feeder radiator on our cars this would not be a problem. With the turbo model, with the IC in the way, less air flow to the radiator is still a question. 214 is my highest temp in the Sky.

IF... your having/seeing higher than normal temps in the DIC, how fast does it return to normal in the DIC with no air flow? With in 2 minutes? More? How long does the fan run on after shut down? 30 seconds? 3 minutes? Is there any sign in the expansion tank of a change in the fluid level? How much? IF these change drastically for you in a short period of time 2 weeks maybe here, then I'd worry some. Changes in the DIC temps not so much worry for me anymore. Your fear is warranted here over your investment in your joy. We all have that same feeling when something on our baby isn't to our liking.

LAC
 
#12 · (Edited)
I don't like my temps going up to 230 and in the heat of the So Cal desert in summer (we can see 114 degrees in stop and go traffic) it can still climb from there.

I have a dual pass radiator going into mine from PAW and a cooler thermostat to try and keep those temps down. 170-190 is where I want her with the new turbo setup so we'll see how it does but anything under 200 in 114 degree heat and in traffic will be a win.

I have both functional hood and fender vents. It takes longer for her to heat up in traffic and it sheds heat very quickly when you start moving but sitting still they can't do much.
 
#13 ·
These discussions have been really helpful...I'm a new owner of a 2007 base in Florida...( I live in Ohio most of the time so I've been like a kid who knows what they're getting for Christmas but has to wait to get it )

anyway mine got up to about to about 213 one day and I was getting concerned.... so I've been reading up on eveyone's experiences..

I just changed the antifreeze and installed a bleed valve in the line....I think I've got the air out but will give it another test when I'm there in two weeks.
 
#14 ·
Before I changed the coolant with fresh Dexcool, it would run 208-215 all the time. This was in 50 degree weather on up. After changing the coolant, it is 205-210. Occasionally it'll drop to 203 for a couple of seconds and return back up.

I am going to replace the thermostat with a new 180 and a drilled hole. Wondering if I should change the sensor also? Could it be the sensor that is the problem for the wide range that people are seeing? I would love for mine to get down another 10 degrees for the norm.
 
#21 ·
But these motors produce more power and run more efficiently around the 185-210 temp range.... why would you want to run that cold other then KR and you're afraid of pushing too much hot air with the turbo?
 
#24 ·
Because when I autocross or do hard mountain drives in 115 degree weather it's really easy to get the temps well above that range. I'm hoping that when I'm pushing the car like that the temps will settle more in the 200-210 range than the 225-235 range they start getting into now. I'll see how it works out. After all, swapping a t-stat isn't horrible in these cars...just not the easiest.

Also, getting a larger bang in the cylinder (more air = more fuel = more power = more heat) means cylinder temps can rise with the larger turbo as well. While aluminum is a far better conductor of heat that iron, getting that heat out of the aluminum is important too in order to keep cylinder temps where you want them.

I haven't seen any data on using different t-stats on these engines and have seen the benefits on using them with older technology engines under forced induction.

Finally I run a Hahn LNF intercooler which, up until now, has kept intake charges where they should be temp wise. It should handle a lot more than what I have been throwing at it. We'll see what it does with this setup.

Where did you find a 160 t-stat?
I believe I found mine on eBay but it's an AC Delco part.
 
#22 ·
I have a red line and live in Tucson AZ my temps use to hang around 198 to 205 in the summer months . I thought that that was running to hot . I did something that I dont think anyone else has tried. I ran hoses to both sides of the engine block comming from the brake cooling ducks. After after installing the flexible hoses and home made brackets to hold them in place the temperature now runs between 192 and 200 I dont know why someone else hasn't tried this since the brakes dont need to be cooled if your just driving on the street
 
#25 · (Edited)
Interesting. Never heard or seen that before here duct work to cool the engine block. Hey if it works, why not? Tucson AZ hot as hell, it was when I was there at least. Photos if you can?

Hotter summer temps we all want our cars to run a bit cooler. Sometimes this is not possible. Keep track of your temps on a regular basis during these hot summer months. Any change from your normal range 190-210, find out why? Low coolant in the expansion tank? Any sign of leaks under your car?
I just cleaned my IC and Radiator with a hose/brush/sponge. Dirty they were, but not now. Lot cleaner, maybe it will help some then again, maybe not?
Lot of loose grime washed away in this most recent process. Years worth maybe.
I did this wash/clean right after I bought my Sky. 6 years later it was back on my list. Box checked off for now.

I had commented on another thread here, a new owner with seats different than the original set up with no power seat height adjustment switch.
After his inspection under the driver seat, no evidence that the car had this option installed.
Then looking under the passenger seat he finds an old I-Pad with Honolulu time on the clock.

You just never know until you look, close. Loose bolts here, a tear in the weather strip there, uneven tire wear, a
chip monk on your intake manifold, could be anything. Ahhh it's ok, I'll check it later. Famous last words.

LAC
 
#26 ·
So, I am sitting in a conference call that I don't need to be in, but can't get out of, and decided to analyze this temperature thing, but need more information.

@Robotech : What radiator and/or oil cooler are you running? And, what horsepower do you want to be able to develop, for how long, without exceeding 210 F?
 
#28 ·
@Robotech : What radiator and/or oil cooler are you running? And, what horsepower do you want to be able to develop, for how long, without exceeding 210 F?
Running the PAW dual pass radiator (so a lot more coolant hanging out in the radiator for a longer period of time) and no additional oil cooler...yet...will be installing an oil temp gauge at some point in the future to keep an eye on that (along with oil and fuel pressure gauges in the cockpit since I already have a fuel pressure gauge under the hood).

Peak HP is 450-500 (450 on 91, 500 on E85...these are targets but I suspect it will be lower knowing my luck). However, I won't know my power curve until the engine is in and dyno'd. I run a dyno of sorts on HP Tuners that dyno'd the car at 249 whp when it dyno'd 251 whp on a real dyno under the exact same conditions telling me it's pretty dang close so if I use this HPT dyno on the track I'll have a better idea of what the powerband looks like on track.

The issue is on the Autocross course, we are constantly accelerating in low gears running through the powerband. We do this for a minute then set for a while. Thus we're heating the coolant in the engine not going over 60 mph (and usually only a handful of seconds at over 40) then sitting for 5-10 minutes in the staging area with no air moving over the radiator/IC. We do this 3-4 times back to back.

This and sitting on the freeway in bumper to bumper traffic is what heats up the car the most. Otherwise, it's not so bad. Cruising on the freeway I'll probably be in the 180-195 temp range as now I'm usually in the 200-215 range when cruising. Also I figure the temps will be more stable due to the larger radiator.

Very true. Just because you run a 160 t-stat doesn't mean you run that cold, only that it opens earlier.

I have the 180 t-stat in there now. I can't get below 205 normally. Usually 208-210 is where it runs. So with a 160 t-stat, I'm assuming I'd see the same shift. 185-200 coolant temps.

That would be perfect, IMHO. Plenty hot enough.
The ECM considers 155 coolant temp (along with a minimum run time that is far less than what is required to get from 110 and lower to 155) as "warmed up" and at coolant temps above this range the engine logic has no limitations placed on it due to coolant temp.

Like I said, should be interesting to see what happens and worst case scenario, I go back to a 180.
 
#29 ·
Does PAW give you any performance values for the radiator? Their website is a little sparse. Something like rated horsepower, or heat flow would be really nice.

Your autocross scenario is quite a bit different than a canyon carving scenario, in just the way you describe. In autocross you are putting heat into the engine in short bursts, not unlike a drag racer except that they may not do runs quite so close together. I would think that you would get some cooling between runs either with a fan pulling air through the radiator or with the hood open. Either way, sub-cooling the engine will provide some help since the entire system will be a sink for the heat that the radiator cannot disperse.

The heat load while canyon carving is of much longer duration, and starting at a lower temperature isn't going to help for very long. Trying to run at a lower temperature will actually make it harder to maintain that temperature since you will have a smaller delta-T for the radiator to work with. The two main reasons that I understand for manufacturers to have increased operating temperatures are efficiency and the ability to run smaller radiators, although you have evaded the smaller radiator issue and probably don't much care about efficiency.
 
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