Just a little info, I changed the thermostat to a 160* as part of the Chuck Cow tune. By the way I love the tune and new performance of the A6. Now this was back a couple months, Maybe mid June, anyway things were fine with the temps, constantly around 185* to 195* depending on the driving conditions and Hwy speeds. At idle or setting at lights it would run up to 207*. never over 212*.
Starting just a couple weeks ago I noticed the temps up around 218*, Maybe 223* at a signal light. But it was hot as Hell in north Texas so I thought all's good. Last night while out and it was a wonderful cool night, maybe 85* outside temps. I started seeing temps from 220* to 228*, stop for some wings and took a quick look for debris but no signs of any thing blocking the air flow and the fans were running wide open. So a couple hours later I head out to visit more friends and its back up to 228* and getting hotter by the mile. I return home and by that time temps are 235* to 237*, its never run that hot even in mid of some really hot Texas heat.

Is there any knowledge of a bad batch of thermostat form any of the vendors or has anyone experienced this before.

Where could I pickup a new thermostat and whats the PN#, Could I find one at AutoZone or O'railys, If so I could replace that first and see If that works.

Joe

 

You can get a Mr Gasket #6367 from Autozone for about $14..
Be sure to test the new one for proper operation in a pot of water..

 

I know you checked for debris, but did you look between the rad and condensor?

I have had that problem on my 00 and my 03 that caused both to run hot. I have not cleaned out my 08 yet, but plan to do it soon.

Just a thought. I'll agree it does sound more like a bad thermostat.

 

Thanks for AutoZone Part No. I'm heading that way now.

As for the space between the Rad and Cond, I've blown air through it and tap on them with a rubber hammer. There was not that much debris that fall out on the shop floor, more than I would like to see back not that much.

How else would I clean that area better?

Thanks

 

Summit Racing.... SLP thermostat..... use part #100228 for 2008 and prior models or part #100229 for 2009. Summit ships very fast. Mr Gasket t-stat is crap IMHO.

 

Let me know if ya figure it out.

 

Was this with or without the A/C on? Because the radiator fans run 100% of the time when the A/C is on but when the A/C is off, then turn on when the temp reaches 228*.

 

I took it apart the enough to pull the condensor away from the rad a bit . Before taking it apart you can lay on the floor and shine a flashlight up in between them. You will be able to see if anything was in there.

 

Just a bit of an update, I spent part of Sunday checking everything I could thank of that might be causing the overheating issue. I wasn't able to find a new thermostat locally but do have two on order now and I believe I'll change that out this weekend.

I checked the coolant reservoir and verified the fans were operating, I also washed the radiator and condenser, then blowed everything down really good. There sames to be very good air flow through the radiator when the fans are running so I feel confident there's no debris cause air flow issue's.

On my test drive, it was running 225* to 228* and as soon as the speed was below Hwy speeds it went right up 235*/ 237*. It would drop back down when the speed picked back up. Not sure how high the temps would have went If the speed wasn't picked back up and it was a beautiful day, outside temps maybe 85*.

If someone can help me to understand the air pocket issue and just whats the procedure to correct this? When I initially changed out the thermostat I filled the cooling system very slow over about a five to six hour time period. I kept a very close watch on the coolant level for days and never added a drop.

Thanks for help.

 

Hey Joe...Here's what I've seen....

When we install the stats here, we use a vacuum tool to completely remove the air from the system before the antifreeze goes in. This way there are no air bubbles.

NOT using this tool makes the antifreeze fill up much more difficult. While it's totally possible to do it right, many guys don't.

This will leave an air bubble in the system that will only grow with temperature. Eventually, the bubble or steam in the system will get so hot it ruptures the stat. causing problems like you see.

The second issue we see is the gasket/stat not seated correctly. I know it looks PAINFULLY SIMPLE and everyone out there has been working on cars since they were 15 1/2 years old, BUT it's soooo simple that many guys mess it up. It's VERY important that it's in correct.

The misaligned stat will cause a small air/coolant leak that you will never pick up.

A few points to note... It was hot out, and now it's VERY HOT OUT. Second, you might have gotten away with it early on, but...as time goes on it will get worse.

Lastly. You'll look at your coolant bottle all day and it looks like it's FULL.

I likely isn't. Just because the level in the bottle is good, does not mean it's full cause you can have an air bubble in there holding the coolant up making it look full.

Call my office and we'll send you another stat. Please return the old one.

Just be sure someone has the COOLANT VACUUM TOOL for you to use....(or a shop) to eliminate any chance of error.

It's soooooo painfully easy that a large percentage of guys mess it up.

Call me if you have questions. Don't run that thing hot any longer...You'll absolutely make more trouble.

Chuck CoW

 

I'm not sure if we are having the same problems but mine over heats of course when its hot out and city driving which is slow and higher rpms if i keep the rpms down it doesn't over heat then faster driving with lower rpms the gauge goes down slowly Does anybody think its a flow problem? My 442 455 had issues for 8 years and a fellow told me to drill 4 holes 3/16" on the perimeter of the thermostat and all my over heating disappeared!! After 2 complete over gauls of the engine !! I need input!!

 

I have a 2008 corvette c6 123000 miles it got hot when I started it up to drive it got hot quick it went up to 255 told me to shut down so it did let it cool so long story short water pump was working fine so I started checking my hoses and found I had a broke hose small house comes off over flow bottle goes to the radiator it has a plastic t in the middle the t went bad and broke and clong up the hose and radiator I replaced hose cost 110 hose 168 for radiator car is running like new again

 

That may be the problem, you have not purged it. The shop manual says that after filling the coolant you let the temps come up than you bring it up to 4000 rpms and keep it there for 2 minutes than refill. When i changed my coolant i actually had to do that 3 times, with high rpms. The last one purged all the air.

 

Forgot to add, with the coolant cap off, while running it at 4000 rpms. In my case when i backed if some coolant overflowed during the burp and purge. No big problem. Just be ready for it.

 

I would check the following --

1) plug connector ... this is a classic symptom of the fan plug connector failing. It is located on the lower passenger side of your fan housing .. disconnect it and inspect the three terminals. they tend to melt --- example shown below ( pulled to the top to take the picture )




If this is your issue you can either buy a new harness or splice around it.

2) As was previously mentioned by Chuck, air pockets are very common. use a vacuum tool to eradicate any possible air pocket

3) make sure your fan are coming on .. turn the air on high when you first start the engine--- do you hear or see them coming on?

4) check to see if the T-connector on the small hose is leaking or cracked. It runs from your fill container across the top of your engine. The T-connector is right above the power steering unit.

 

A vacuum tool is a great idea because it eliminates bubbles and air pockets and simultaneously tests the system

for leaks that can let coolant out and air in.

While it can happen anywhere in the country, I mostly see southern cars and hot climates melt the fan connector.

Also, guys that don't have 160 stats and/or fan settings set too aggressively will also melt the connector.

Air pockets are the big killer from improperly filled cooling systems.

We actually remove the FAN/HARNESS union connector and "bug" the wires together with some really

high quality "BUG" or crimp connectors....Soldering just adds insurance.

Moving the factory fan ground location also helps.

Chuck CoW