Vette_Fan

Tired of the high temps for a while, I knew I needed a Radiator flush at some point, was being lazy... So finally did it today.

Super easy but took about a couple of hours though.

1. Drained the old fluid by opening the bottom plastic drain plug. (petcock plug), located at the passenger side/bottom by the radiator.
2. Hand tightened the plug and filled the reservoir with Distilled water only, let the car idle 10 minutes or so and heater full blast.
3. Repeated step 1 & 2 - twice.
4. Finally filled the reservoir with Distilled water ONLY. Will run the car for a couple of days for short trip to town; since it's summer and CA if pretty hot, no freezing here anytime soon.

In a couple of days will drain water, and refill with 30/70 mix Dexcool/Distilled water, or 40/60 mix (maybe); + add 1 bottle Redline's Water Wetter and be Done!

Your feedback/comments?

Sunnyvale Dave

What did you do with the old fluid?

Vette_Fan

Hahaha... This early in the morning (or night I shall say)... and this is what you wanted to know? Lol.
Bottled it, of course.

Not So Fast

Sounds like what I did minus the filling with water and driving for a few days, it took 4 drains to come out clear so that was about 3 hours time frame, then I just added the undiluted coolant and then water, SLOWLY I might add and have had no problems with air gaps or bubbles in the last year.
NSF

Landru

Nice DYI project, left this to a dealer since disposal inconvenient for me.

One thing happened I'll share, just had heads/cam/tune done on my '08 Z06 w/ 60K.
Owned it since new, never seen anything but casual use, never raced/tracked.
To do cam all 3 coolers had to be removed.
Shop sup sent pics of what all 3 looked like on their rear sides.
Totally caked w/ crap, cost a hour shop time to clean.

Blew my mind since I'd often hosed off any debris I could see on front of radiator.
Never thought of the other 2 and never occurred to me backs of any w/could get filthy.
C5 I get but I mean HTH w/could it happen on a front breather C6? Nawww, but it sure did.

It isn't easy to do but somehow get an eyeball on the rears of the coolers, especially Z51/Z06/ZR1 cars w/ extra coolers.
Guessing a lift would be ideal, use a flashlight however they're observed.
If there's ever been a cooling issue for those living in hot climates, cat tends to run hot?
Check coolers, because as C6 ages this weird stuff will happen regardless how or where its driven.

stingray71

No freezing during the summer, but what about boiling? It boils at 212 degrees (and lower temperature based on altitude)

1bdvet

Don't bother with Water Wetter, don't waste your money, others will say something different, but not recommended for daily drivers, or weekend fun car!

Mostly used for racing, with straight water, can be used with antifreeze but don't see any benefit, cause you antifreeze is enough to keep car cool.

Vette_Fan

I already bought Water Wetter, so might as well use it, even if it saves only 2-3 degrees.



Yeah, I am concerned with air bubbles too. Anyone knows the method to remove them? I just squeeze the upper rad hose to allow it to pump fluid into the rad, hoping it will release air.

Water itself should be fine for short distance drives.

Sox-Fan

It'll boil much higher than that, it is under pressure.

brokenblinker

Hey Vette Fan! I'm also in SF Bay area.

I picked up my 2007 base Corvette a month or two ago. I noticed today while really ragging on it for the first time up page mill (Super twisty, <50 mph at all times road) that my oil temperature is getting into the mid 250s. This seems kind of high to me, but I don't have much experience with this car. I've previously been very into motorcycles, and this is a common occurrence for high-performance bikes. As soon as I got onto a road that had higher speeds and more airflow, it lowered pretty quickly.

How high was yours getting that you noticed it?

Sox-Fan

250 oil temp is not a problem if you're using synthetic and have been pushing the car hard.

brokenblinker

Now that I think about it, i think I saw 261 once, but most of the time during that 15 minute run, it was in the mid 250s. This road is constant corners/braking/acceleration uphill at low speed. Seems reasonable and I believe its using the synthetic oil from its last dealer oil change.

Vette_Fan

Possibly, but my personal choice is much lower than that. 250-260 is on the high side for me. I'd take measures to keep it cooler, if I was pushing the car like that on regular basis.

That's what I thought. It's been said water alone is a better cooler than any additives (or water alone with Water Wetter). Antifreeze (coolant) helps from freezing the water. It hardly does anything for the heat.

If it's dealer changed oil, then it is synthetic oil. Personally, having it's synthetic oil isn't enough for me, I'd still take measures to keep the temps down (but that's just me).

Vette_Fan

Mine was coming clear on the 1st water run. Not sure why it took you 4 drains to get clear water. Then again, mine was light Pink - I am guessing it wasn't even Dexcool, probably just water and Water Wetter. Then again, I got the car from Oklahoma, where it freezes. So I'm just guessing things...

Sox-Fan

Water under pressure has great cooling properties, but it has no lubricants or corrosion inhibitors. Distilled water helps, but I do run a little dexcool just for the added properties.

brokenblinker

Yeah, I don't love it either. I'm not used to seeing oil temperatures that far above coolant temperatures. I know I was ragging on it, but it still seems a bit high. Coolant overflow seems very clean and clear, so I'm not quite sure what the next steps are.

I have seen others with similar temps be told that there was something wrong, but they were seeing those temps during highway driving. I see more like 230 when completely warm on highway, this was just during an extreme session.

victorf

When I changed out the OEM radiator with Dewitt, took me two days repeated with 18 gallons of distilled water to flush, even than, visually it still was not 100% clear.

My original fill was not neglected, coolant was done twice before Dewitt, but to get it 100%, it takes time.

cgladish

I haven't done a radiator flush in years ( not personally, but have had shops do it ). I recently had a new pump installed.
prior to this, the freeway temps were right around 198° F. it might get to 210°F in traffic. afterwards, it's been running around 207°-209°F, pushing 220°F in traffic. initially, it took a while to bleed the air. took it back this weekend and, their confident there's not air in the system. the overflow cap seemed a bit deteriorated. will put a new one soon. I've seen the oil temp into the low 260°'s.
to be continued...