2006 C6Z overheating issue

[NORTY]

Ok, I've owned my car since new (Feb. 2006) my coolant temp has run around 192F to a max of 204F (after some sitting in traffic on a hot day in Hemet, Ca.) Anyway, my car has begun to heat up to 240F now. I looked from underneath for something obstructing the radiator, but only found the A/C condensor and engine oil cooler that have been there the whole time. I got under the car yesterday and blew out the impacted crud (dirt/sand grains/leaves) from the radiator and condensor, but I don't feel like I got enough material to make this marked difference in temperatures. Checking the coolant resevior, it is up to the safe range. (About 1.5" from the top when stone cold.)

Now, before I go any further, the car was tuned November of 2009 (37,000 miles) and the fans were adjusted to come on a little earlier. I had no problem with the tune last summer, so I ruled that out. I hear the fan turning when I shutdown all the time. So I know it's working. I have TR-6 plugs installed which are 1 step colder than stock, to keep head temps down. (I was getting a slight ping on the dyno during tuning.) I now have 48,000 miles on the car with the orig coolant. (Yes, it's almost 6 years old.) Due to change in year 7.

I noticed a lot of stuff embedded in the A/C condensor, but I don't know how to get @ the back of it with compressed air to blow out the crud. There's tons of little sticks and granules that I'd like to get out. How do I separate the 2 radiators without disconnecting the lines to the A/C or engine oil cooler? There's just no room to get a blower between them. The plastic shroud is very defiant. They should call it "the plastic shroud from Hell!"
I tried squirting water from the underside between the fan blades on the rad fins but all I got was wet. (TIP: wear a rainsuit!)

[c4c5specialist]

HI there,

There is probably too much sand and debris in the radiator fins to effectively flush out that way.

Try a tool from THEXTON, part number 467E and attach it to a hose.

Flush out your radiator and condenser.

Allthebest, c4c5

[NORTY]

Thanks Paul, I'll look for that tool.

I took the car off the ramps and decided to take the car for a shakedown drive, just to see if what I had already done, had made a difference. I was skeptical because the debris flushed out of the radiator ( sand granules, a million grasshoppers with wings, rubber granules, leaves (small)) didn't seem like enough material to increase the coolant temp 40F, but it was.

Now my coolant is running 192-202F, like it used to. I was in the mountain twistys for my evaluation.

In talking with other C6 drivers, this appears to be a common problem. (Not just Z cars either)
Some remove the fan and shoot water/air into the fins forward (this, I did.)
Some shoot water down the front of the radiator, and the back of the condensor (this, I did.)
I haven't found an easy way to remove the "Shroud of Turin" yet to clean the front of the A/C condensor. I almost cut the plastic from hell with a soldering tip. I know how soft the condensor metal is if I used a blade. Then, I'd just plastic weld it back up when done. I'd still have that small gap between rads to contend with but right now, it's fixed!

To all you C6 drivers, if you find your coolant temp rising all of a sudden, you might want to look for bags/paper or other stuff blocking your airway. If you find nothing blocking your radiators, then blow it out (towards the front of the car.) It's easiest from underneath.

It's a small wonder why our cars don't overheat when new, with 3 radiators inline...and the last one is for the engine!

[froggy47]

Originally Posted by NORTY

It's a small wonder why our cars don't overheat when new, with 3 radiators inline...and the last one is for the engine!

My thoughts also.

:)