Still working on my overheating problem,I am going to change both the upper and lower hoses and the water pump. My reasoning is I don't know how old these parts are. I have a flex fan that is still in the box and was wondering if it would matter if I took off the clutch fan ...car dose not  have A/C. So would it matter if I changed the fan?                       Thanks Rick

Your overheating problem could possibly be caused by a bad fan clutch...it does happen.  One way to check it is to let the engine run up to normal temperature than stop the engine.  If the fan keeps on spinning the fan clutch is bad.  A good fan clutch should stop nearly as quick as the engine.  

Im in Agreement with not using a flex fan. Ive seen the damage they can do when they let go. I would hate to see someone near it at that time. The one I know of that came apart was an aluminum blade that went thru the shroud and dented the hood. Probably come thru one of our fiberglass hoods.
Remember that the car used to cool so you know if all your components are working its a proven system. You havent done any engine work that would have changed anything? When does the engine overheat. If you want to try another fan clutch I have the one off the 72 I am not using. You can give it a shot. Also does your shroud have any breaks in it? Have you checked the actual temp? Does it push coolant out the over flow while running or when shut off? Did you try changing the thermostat? Does the lower hose collaspe while driving. Im not that far from you if you need a hand sometime.
Rodney


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What kind of shape is the radiator in?

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 I changed the clutch on the fan two years ago,when I take the car out it overheats as soon as it starts to get warm.(don't take long).The hose going into the the thermostat housing gets really hot and if you grab it you can feel the pressure on it,the strange thing is the radiator cap is cold and has no pressure on it.I've been told by a couple of people the the bottom hose has clasped or that the impeller on the water pump is bypassing. So not knowing when these three things were last worked on I decided to change them.As for the radiator I will look it over while I have everything apart.Oh I did change the thermostat and it didn't help.  As for the flex fan from your experiences I think I will stay with the factory fan setup.As soon as I find a way to move the car to a place to work on it I will change the parts and post the results.....right now I'm a little gun shy on working on anything in front of my house.

|UPDATED|11/22/2012 7:27:32 PM (AZT)|/UPDATED|

Try removing the T-stat and run it....you could have gotten a bad new one. Hose going into T-stat hot and under pressure sounds like T-stat not opening

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DanT

There may be another issue namely with your engine, check the water and make sure there is no oil in it and also check the oil on the dipstick, if the oil on the dipstick is creamy coloured, you may have done a head gasket. Advanced timing will also make the engine run at a higher temp, I had the same problem with overheating and found the distributor lock bolt had loosened and the timing advanced on it own enough to cause overheating.

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 Well I got the top hose replaced,water pump replaced then the problem  ....I couldn't find the right bottom hose. I found plenty of hoses ,but none had the spring so I called corvette america and order one. Should be here Tuesday. I want to give Rich (Yostusota) a thank you for the phone help today. Well when I'm done everything except the radiator has been changed in the cooling system so I will see if problem solved.                                     Rick

 I think gunslinger hit the nail on the head the spring on the bottom hose was shot,But instead of just doing it I decided to replace everything (no telling how old the hoses were and water pump was original.No water in the oil (thank goodness)

|UPDATED|11/23/2012 6:31:41 PM (AZT)|/UPDATED|

You guys talk about Flex Fans letting go.  The previous owner of my '73 BB had the stock clutch fan fly apart.  It took out part of the shroud and blew a large hole in the hood!  It took him 3 days on the road to get parts and get it fixed.  I never liked the sound of the fan on this engine. At higher RPM's all I can hear is the fan.  It makes me want to shift to get rid of the crappy noise.  I'm going with DeWitts dual electric fans and hopefully, they'll only come on in traffic.

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1973 BB 4-Speed Coupe Project Car

If your fan is as loud as you say then someone may have replaced the original fan clutch with an incorrect one.  That's not uncommon when they're replaced.  

Flush out that radiator while you got it apart....I mean alot!!! I flush mine 2 times every year....it looks like stalactites in there!! Or I hate to say remove it and have it cleaned.....but...flush kits are cheap and clean out the goop really good...LMK!!!!

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My first parade at Carlisle 2010

If you're flushing it twice a year and getting out lots of junk, then it sounds like there is something else wrong with the cooling system.  

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1973 BB 4-Speed Coupe Project Car

Rick, I had the same symptoms and was finally cured by a bottom hose with the spring. What was happening was the bottom hose without the spring would collapse while driving. The spring cured it - everything else on the car was new so no other gremlins.

John...the problem with my car is that the radiator is original and had little to no maintenance in its life..I may remove it this winter and get it cleaned out...hope Rick doesn't have to do that and the new hose with the spring works out.

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My first parade at Carlisle 2010

Got my new hose today from corvette America. If all go right I'll be putting it on Thursday afternoon( got a interview in the morning) ....so I will post after I try it out will let you all know if successful. Rick

|UPDATED|11/27/2012 5:56:50 PM (AZT)|/UPDATED|

Hope the new lower does the trick.  Running abit without the t-stat in place would also let you see it the radiator is indeed cooling enough.  If there is a build up of rust and/or scale in the radiator that could impede the cooling.  A fellow on the Model A club I've joined has recommended running pure vinegar in the cooling system to dissolve the crub.  He claims it cleaned everything out clean as a whistle.  I know the cooling systems between a Model A and a C3 Corvette are quite abit different but they're very similar in function.

 

Also make sure the radiator support seals are in place.  Any air slipping through the gaps between the radiator support and the radiator is air that isn't helping to cool.

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Jim Olson 

"The Toys"...!!!  Save the Wave!

Where I've been in a Corvette...!!!

Just two comments.

Good flex fans work fine & will tolerate 10K RPM. I've used them on various cars for many yrs with no problems. If your car is overheating & you have a correctly placed fan, clutch,flex or electric you have other issues. Making sure all air goes through the radiator is a real problem & will cause overheating at highway speeds on C-3's. If your bottom hose is being sucked in your radiator is probably clogged. Water wetter will really help bring the temp down 10-20 degrees & running a 25% antifreeze mixture will help too. water dissipates heat much better than antifreeze, but you need some antifreeze to control corrosion. I personally use flex fans on 2 high performance engines & they keep the engine right at 175-180 degrees in all weather. I also have one with electric  fans that also work  fine. Flex fan can be noisy , but if you exhaust is noisy you'll never notice it.  So I think it really comes down to a personal choice. Flex fans can be adjusted in & out to really get the proper air flow which is critical to coolling efficiency.

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I found this on Willcox Corvette and thought it might help.

http://willcoxcorvette.com/instructions/johns_cooling_article.pdf


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Well I got everything changed,man what a pain in the *#*.I also did a couple of small fixes. Well ran out of time so tomorrow is the big day to see of I fixed the overheating problem. If not then the only thing left is the radiator. Rick

I am another one in the no flex fans club - I race in SCCA events and they are not permitted for a darn good reason. And I have had them let go, with one in particular creating a nice hole in the hood of a classic 1969 Ford LTD.  A fan with a clutch will be as effective in cooling, if not more so, and is much safer. Check the clutch!  Other items to check that caused some heat problems with my C3:

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C3: 1979 Corvette Coupe, Auto, L-48, Red/Doeskin (my wife's fave);

Rick, if you do have to replace the radiator get the direct fit aluminum one. I got mine from Corvette America but MAM and Corvette Central sells the same one. Made an amazing difference in my car! Good luck and hope it works out!

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"Down on the Boardwalk...

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Well I let the car  running and got it up to temp....then drove it for a little the temp got to just below the 200 line and stayed there.(I have a 195 thermostat) So hopefully this solves my overheating problem.                                 Rick

Yeah! I love when aproblem gets solved! Great to hear, Rick!

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"Down on the Boardwalk...

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