267K miles, original owner. Garage replaced thermostat 1,000 miles ago when temp went to 260 and had percolating sound. Happened again yesterday and told I have a warped head, but there has been there has not been any smoking from exhaust, loss of compression,engine misfire,coolant or oil loss, or coolant mixed w/ oil, all of which I would associate w/ gasket or warped head. I'm not a mechanic, but these would appear to be some signs if that was the case.

Prior to yesterday, temp would rise to 230 when idling, but drop to 218-220 when moving. It has been extremely hot in Atlanta and felt that may have contributed to some of the higher operating temp?

Any help would be appreciated,thanks

 

First,
Congrats on a long term relationship with this car ! There are so few people that can keep a nice car that long...getting close to 300K is something to be damn proud of !

next, I'd call the mechanic and tell him that he is a LIAR and a THIEF or just simple. His choice. A warped head? I'd love to hear the logic that led him to that conclusion.

You are absolutely correct... a warped head comes with some other symptoms..like water loss, mixing, misfiring etc...

that shop is attempting to CREATE some work.

Take your radiator top shroud off and clean out the trash thats trapped inside. The shroud MUST come off. No other way to see or remove the debris.

At that milage, there is a lawn bag full of crap in there. It blocks the air flow. Car over heats.

Then I'd seriously consider having the radiator replaced. Servicing these throw-away plastic radiators cost as much as a replacement. Less than $100 to replace a stock radiator. A bigger, all aluminum unit that cools better cost as little as $200...and does so much more.

Your problem is far too common and way too easy to deal with. Don;t fall victim to crooked shops and mechanics that have never had ANY training on Corvettes, and will throw parts at your car (wallet) until it either works or you go broke.

...warped head? how do they figure? just because it overheats?
That knee-jerk diagnosis is supposed to justify an expensive "shop repair" ? uh-huh...couple thousand $$ worth.....

are the fans coming on at the right time? 228 is when the main fan starts,..or when a/c is turned on. The car should go down to the 200 area when traveling at freeway speeds. Yes, Ambient temps DO effect how hot the car gets..but they usually only make cooling take longer. A 100 degree day with hi humidity will drive the operating temp up to 230+ in traffic....but it will drop to <200 after cruising at 60 mph for a few minutes. The car MUST be moving to cool efficiently. The fan is just a substitute for movement. The engine needs fresh air and it comes from motion.

This car is what is called a "bottom feeder" because it sucks all of its cooling air and engine air from below...like the mouth on a cat-fish. This also lets it vacuum up everything off the street...so you get trash blocking air flow. You CANNOT see the trash where it collects unless you pull the top shroud off the car.

If you ask, I'll tell you how I really feel about rip-off mechanics, crooked shops and con artist that take advantage of people that walk in front of them....

Get yourself a FSM. A REAL set of manuals cost approx $100...less if you shop around. They will tell you how to do alot of this work yourself but the most important thing is that they will educate you so that you are a step ahead of any shop that tries to dance around and create work thats not necessary...or appropiate.

Good luck !

 

Thank you very much for your input and appreciate the qick reply. I'll go with your suggestions this week end

 

Leesvet covered everything important. Saw you are in Marietta. I'm in Norcross and just replaced the radiator on my 85. It's not hard, even for an idiot like me. I only have 100k on my odo and the space between the radiator and condensor was half filled with leaves and garbage. My radiator had given out completely. Napa had the stock replacement in stock and it was only $120~. If you still have problems, call Versatile Automotive in Marietta and ask for Andy Mullins. Tell him Mike sent you. He's my mechanic / speed shop. He does EXCELLENT work, stands behind his work, and will beat damn near any price you find anywhere. Used him for over 3 years now. Great guy! PM me if you need the number or more details.

Good luck!

 

Same thing happened to me. It was my rad that was gummed up inside. New rad, and problem gone.
P.S the rad looked clean when i looked in it but it was not.

 

To amend and complete my previous post....
I want to give you everything that you need to know in order to do this and be successful!

Taking the shroud off is not difficult...you need a 10mm socket, extensions, 1/4" drive preferable....then a 4 or 5mm socket? I forget that one...its for the row of small bolts along the front edge of the shroud under the air cleaner box.

You have to remove the top 2 bolts from the main fan X brace.
Remove all the 10mm bolts on 3 sides of the shroud. Look down along the lower sections where the top meets the lower shroud. There will be a bolt at and around every bend or corner where the top meets the bottom shroud.

Look at the a/c dryer. It has a couple bolts in the mounting bracket. You may need some long tie-wire to pull the dryer up and hold it up out of the way to pull the shroud.

There is a small bolt thats hard to see/find thats on the passenger side front of the shroud on the 45 degree angle of the rt side of the shroud. Reach down and feel the flat surface of the shroud to find this well hidden bolt.
You'll need to drain some coolant off...might be a good time to change & flush. D/C the top hose.
IIRC you will also have to d/c the trans cooler lines (the first time you do this).
Remove the air cleaner ( actually the first thing you do)..remove the duct so there is nothing over the top shroud.

It takes some wiggling around and manipulation but it comes straight up and off.
Look between the radiator and condensor...and you will see what we're talkin about !

I've found dead birds...wads of fur, hair. Plastic bags, coffee cups...leaves & rocks. All this junk blocks fresh air flow and prevents heat exchange.

Pick out all the trash and then wash out the area. Now, if you were to drop in a new radiator it would be near done IF you had one sitting there...D/C the lower hose and it lifts up and out.
Whatever you decide on the radiator, since you know how you can do that later if the clean out does not help.
Here's the BIG trick...

Take your top shroud and LOOK closely at the ends where hoses fit thru the openings and look at the things that had to be disconnected to get the shroud off.
Now get the hack-saw or dremmel and cut a path for the hoses and lines to fit thru so future removals can be done without having to disconnect anything. This can be done without loosing or interferring with any of the mounting tabs, bolt holes or anything else. Just study the part well before hacking away...once cut its that way forever.
Now you can reinstall or remove without hassle. I can take the air cleaner off (2 thumb screws), remove 2 big hose clamps on air ducts, then use a cordless driver to get the 10mm bolts and the 6 smaller bolts and have that shroud off in 4 minutes.

When you reassemble make sure the rubber mounting blocks for the rad and condensor are seated and everything lines up as it should. Once you see inside you will understand all...

The condensor can be partially lifted up to help with washing out trash and crumbs...be careful..its aluminum, tubing that bends real easy and its full of freon under pressure, so don;t push your luck bending it around too much. I use bungees to hold the condensor and rad up off the floor of the lower shroud so I can wash in there. Now, I pull the shroud every few months just to keep the trash from getting too thick.

Be careful when washing & working in there to avoid bending over the fins on the radiator or condensor. Those are fragile and very easy to fold over and darn difficult to get folded up again... I wash backwards thru the radiator to help rinse out dirt and loose stuff. Sometimes I'll soap it or use a wheel wash ton clean the aluminum...but again, don;t rub or spray TOO hard against the soft aluminum fins..

If I've missed anything in the proceedure...I'm sure someone will jump in and add whatever I forgot...(happens a lot lately).
The first time...its an hour to pull the shroud. Locating all the bolts is the hardest part. next time, its 15 minutes without a cordless driver. My cordless with the socket adaptor has got to be one of the handiest tools that I ever bought to help speed up the disassembly of things like this.. A small cordless drill works as good because it has more torque and can handle the added weight of extensions and larger sockets.


Good luck and have fun! I'm sure this will improve your operating temp situation without having to get your heads machined....or replaced.

 

Thank you all very much for your help. Turned out to be bags of leaves and clogged/damged radiator and condensor. I used Andy of Versatile Automotive 1726-B Hazelwood Dr.Marietta GA, 770-789-4928 and highly reccomend him for your automotive repair needs. I was so impressed by him, I've taken my Jag XJ-8 to be serviced by him.

 

Told you Andy would take good care of you.

 

I have that disturbing faint smell of anti-freeze when the engine is hot. no signs of leaks on the floor EVER. Temps run in the normal range. It is an 86. I have put 2k on the car since I bought it with 15k on it 3 months ago. It is aluminum heads with the oil cooler and a heavy duty rad. Any of you guys know where these things start leaking first. Just working through the few problems this little jewel has.