help with overheating 79' 308 USA | FerrariChat

help with overheating 79' 308 USA

Discussion in '308/328' started by Minoru, Oct 11, 2021.

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  1. Minoru

    Minoru Rookie

    Sep 25, 2018
    35
    Japan
    Full Name:
    Minoru Maeda
    Hi, folks,

    I have been worrying about HEAT issue of my 1979 Ferrari 308 carb USA version.
    I faced overheat before and I have done the followings but the situation is not improved yet.

    - Changed the coolant to EVANS (https://www.evanscoolant.com/),
    - Foam under hood replaced,
    - Radiator re-cored, -> http://308.emz-style.com/1633-2/
    -> I asked a Ferrari radiator specialist in Japan. He is familiar with that in Japanese climate.
    - All coolant hose replacement, http://308.emz-style.com/1884-2/
    - Water pump replaced to Superfomance #121255 http://308.emz-style.com/1826-2/
    - Heater hose replaced, http://308.emz-style.com/1892-2/
    - New expansion tank cap -> 1.1 bar Superformance 137644
    - Thermostat and Fan switch changed following Birdman's site. http://www.birdman308.com/service/coolant/coolant_troubleshoot.htm
    - Radiator fan replaced to ZIGRO http://308.emz-style.com/radiator-fan/
    - Additional radiator fan (pull type at the behind of the radiator.),
    - Foam under hood replaced,
    - A simple shroud (guide?) made at the top of the radiator,
    - System flushed (including heater cores)
    ->I took much care of the pressure level.
    - System was bled following Birdman's web site. http://www.birdman308.com/service/coolant/coolant_bleed.htm
    -> I did short drives & bleed more than 10 times.


    Note: http://308.emz-style.com is my web site. Sorry for that the all contents in Japanese..

    After those, the current situation is as follows;
    - Outer temp is around 80F.
    - Checked Coolant level -> OK.
    - After around 10 minutes drive, the water temp reached 195F. Fans started.
    - Heater Opened. Hot air flowed. (meaning heater core worked.)
    - The temp increased gradually, finally reached the next scale of 195F.
    - I stopped the car and idled for a while. the temp tended to increase,
    - I stopped the engine and opened the radiator cap with care,,,
    The hot coolant (Evans) overflowed from the filler neck.

    It is very strange that Evans overflowed because it does not boil, meaning the volume should not be changed.
    I suppose that Air came in from somewhere or there was still air pocket somewhere? Actually when I bled from Thermostat housing, the water level came down.
    I wish that the temp level should keep just under 195F, and that in idling status, the fans should start & stop repeatedly.

    I am now planning to do;
    - Radiator leak test,
    - Block tester to check combustion gas leakage into the coolant,
    - Install check valve at the upper hose of the expansion tank (or plug the hose.)
    -> The expansion tank is vertical style.

    Do you have any idea what else I should do other than the above??? I would like to know the cause of this issue as well.
    Sorry for the new posting, I checked many threads in FerrariChat, but I could not find suitable answers.

    Thanks,
    Minoru

    PS
    Sorry for my poor English.
     
  2. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,709
    Full Name:
    Mike 996
    The Evans doesn't boil...and neither does a proper mix of antifreeze/water...at least at any coolant temperature that should ever be seen in an engine. BUT both expand (volume increases) as they heat up. So if the coolant level is higher than it should be when cold, it will overflow/spit from the vent tube when the car is at normal operating temp.

    From your post, I ASSUME that you had some problem with overheating when the car was in its original configuration and you then made all the changes you described in order to correct the problem. Is that right or did the overheating occur after some of those changes were made?

    Obviously it could be a head gasket issue, which your proposed combustion leakage test should confirm or deny. But if air is consistently getting into the cooling system, there is a leak of some sort somewhere.
     
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  3. 308 milano

    308 milano F1 Veteran

    Jan 15, 2007
    5,257
    Montana
    Full Name:
    Kim
    My 308 QV has a bleeder screw and rubber O-ring at the top right hand (passenger) Side of the radiator. Are you sure you have all the air bled out of the radiator? Would think that bleeding the entire system out of the thermostat bleeder would take forever.
     
  4. Minoru

    Minoru Rookie

    Sep 25, 2018
    35
    Japan
    Full Name:
    Minoru Maeda
    hi, mike996, Thanks for your comments.
    Firstly, please check this video. (Sorry, in Japanese. ), which explains the difference between Evans and LLC at the point of 'Boiling point and Pressure'. According to this video, the volume of the Evans is not so changed.
    https://www.evanscoolant.com/how-it-works/benefits/no-water-pressure/ also explains 'No Water Pressure', therefore, I felt that the current situation - the coolant was overflowed - is strange.

    As for your question, that is right. I faced the overheating once when the outer temp was over 95F last summer and I started this project so that I can enjoy this car in mid-summer in Japan as I wish, but the situation gets worse. (Though the outer temp was 80F, the engine got hot.)

    As you pointed out, I will try combustion leakage tester (Block Tester), and Radiator pump pressure leak tester. I hope the cause is NOT blown head gasket...

    Minoru
     
  5. Minoru

    Minoru Rookie

    Sep 25, 2018
    35
    Japan
    Full Name:
    Minoru Maeda
    Yes. I am sure I did bleed from the both bleeding point. I tried bleeding, short drive and bleeding so many times over several weeks.
    I also thought I want one more bleeding point for heater hose as well.
     
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  6. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,561
    California SF bay area
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    Paul
    If it is a head gasket you might be able to confirm with a leak-down test as I show in this video. I had a leak on #4 cylinder. Prior to this I did a number of "block tests" to see if I could detect combustion gases in the coolant but they all showed negative. I believe that when the combustion gas enters the coolant it flows to the radiator and is trapped there so it never shows up at the expansion tank. I replaced my head gaskets and all has been well now for the past two years and 6,000 miles.

     
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  7. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,324
    Tallahassee, FL
    Of course Evans coolant boils. Why wouldn't it?
     
  8. Minoru

    Minoru Rookie

    Sep 25, 2018
    35
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    Full Name:
    Minoru Maeda
    Thanks for the good advise. Did you use a compression tester attachment to blow high-compression air into the cylinder?
    I see, Block Tester does not work in case of 308...
    Did you replace the gaskets for yourself? If so, it is very helpful if you can shown any reference web site and so on.
     
  9. Minoru

    Minoru Rookie

    Sep 25, 2018
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    Minoru Maeda
    Yes, it boils, but the boiling point is around 370F.
     
  10. mike996

    mike996 F1 Veteran

    Jun 14, 2008
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    Mike 996
    I've never really understood Evan's claims re engine protection but maybe I'm missing some vital point.

    In my view:
    The boiling point of Evans is about 100F higher than 50/50 water/antifreeze but the H2O/AF boiling point, - around 260-270F at 15PSI - is much higher than the coolant temp would (should) ever get in a normal engine. IOW, if the engine temp has risen to the point where H2O/AF boils at 15-16 PSI (common coolant system pressure), other damage will have likely occurred due to the excessive heat. The same heat that would NOT boil the Evans can still damage the engine in the same way. IOW, the Evans can't protect the engine from the same temps that would damage it with H2O/AF. At least, that's the way it seems to me; I welcome info to the contrary.

    That being said, I would consider using it if, as they claim, you don't have to periodically change the coolant. Also, there would be no rusting/corrosion of components if a slight seep/drip occurs. In that regard, it might be worthy thing to do. OTOH, if a hose broke, clamp failed, etc, and you lose a lot of coolant...it cost a lot more to replace! But heck, the world is full of compromises! :) In any case, before deciding to use it I would do a bit more research to be sure that the heat transfer capacity of Evans is at least equal to 50/50 H2O/AF.
     
  11. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
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    It's called a differential compression tester also known as a leak-down. The piston needs to be at TDC with both valves closed, you control the input pressure with the dial and it shows on the left gauge (I used 100 psi), the right gauge will show how much pressure the cylinder holds and how much leakage either past the rings, through a valve or - hopefully not - through the head gasket. I did the gaskets myself, it's a bit involved, not something I'd suggest trying if you have no experience. I have rebuilt a number of Fiat and Alfa engines over the years and the F106, even though a V8, is similar. The Ferrari workshop manual is quite thorough but it is not a book that is going to guide you in a how-to manner. There is also some machine shop work you would want to have done to the heads while they are off. But first step is to determine if you even have a head gasket problem. It may not be the case in your situation, it could be something far simpler.
     
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  12. Albert-LP

    Albert-LP F1 Veteran
    Owner Rossa Subscribed

    Sep 1, 2010
    7,816
    around Modena, Italy
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    Alberto Mantovani
    water temperature should stay below 195 F with the standard coolant and standard old fans, at usual road speed driving: It doesn't require any change nor improvement. It looks you have a leak in an head gasket or somewhere in the heads: I would do a simple compression test at your mechanic shop, to check if there is a leak somewhere, at first. Maybe your car has a lot of mileage and it's the time to change the head gaskets.

    Ciao
     
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  13. smg2

    smg2 F1 World Champ
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    Apr 1, 2004
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    Having used Evans for over a decade on our builds I can offer some insight. It does not expand or boil in normal use and operation of an engine. It does not induce galvanic corrosion that water/coolant does. It does burn if it leaks into the combustion chamber due to headgasket failures.
    That said, it requires a complete flush and condition of the system to remove ALL previous water based coolant. The 308 is a right PITA to do this on given the location of the heater cores. I remove them from the vehicle and take the time replace all hoses since we're in there. Left over residual water will cause Evans to not operate correctly, glycol is hygrophobic so it has an affinity for water. That's why the system needs to be dry first.

    It's easy enough to check the water content of Evans with a hydrometer.
     
  14. RodC328gts

    RodC328gts Formula Junior

    Aug 17, 2021
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    Rod C
    Is water temp dial working correctly?

    This is surely not the case, as per your comments. But it’s worth checking
     
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  15. Minoru

    Minoru Rookie

    Sep 25, 2018
    35
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    Minoru Maeda
    Thanks for the detail explanation about Evans. You are right.
    As you mentioned, I tried to blow off all remained water of the all system with an air compressor, and after that I used Prep-Water. But I did not use hydrometer because I do not have it. Yes, I should buy it.

    Minoru
     
  16. Minoru

    Minoru Rookie

    Sep 25, 2018
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    Minoru Maeda
    Thanks for your comments. This time, I used a new fan switch, which enable to start the fans at 180F. As long as seeing the start temp point of the fans, it seems that water temp dial would be OK. Do you have any idea to check it? ( I also thought to input temp gauge into the expansion tank, but I think that the temp in it would be lower than the actual temp.)
     
  17. RodC328gts

    RodC328gts Formula Junior

    Aug 17, 2021
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    Rod C
    it probably is ok.
    I don’t know how to check it. But maybe get a cheap one from Amazon and hook it up.
     
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  18. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
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    Minorou the only purpose of the fans is to mimic the airflow through the radiator when you are not moving. So if you are not moving and the fans are running then it should be just as if you were moving - the temperature will be stable. It may be higher than when you are moving but it will stay steady and not overheat. You should be capable of idling indefinitely. So even if the switch were to allow you to get through some intermittent traffic jams it is still ultimately just a band-aid.
     
  19. Minoru

    Minoru Rookie

    Sep 25, 2018
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    Minoru Maeda
    Sorry, it seems that my explanation was not suitable. Fan switch means Thermostat fan switch, which enable to start fan when the temp reach 180F. Actually in case of not moving, it works and the temp should go down and when the temp became below 180F, the fan should stop. But currently, it works continuously, meaning that the temp does not go down...
     
  20. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
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    Yes I understand, I'm just saying that if there is a problem it will not help to turn the fan on at a lower temperature. It will still overheat.
     
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  21. Minoru

    Minoru Rookie

    Sep 25, 2018
    35
    Japan
    Full Name:
    Minoru Maeda
    Thank you very much for the all who commented.
    I bought a leak tester and a hydrometer to test the system.
    If I found leak, I need to plan to replace head cylinder gaskets. Therefore I am now investigating how to do . I need to buy an engine hoist.

    BTW, do you have any comments regarding;
    I found that the argument regarding this matter.
    https://www.ferrarichat.com/forum/threads/help-with-coolant-leak-overheating-79-308.208033/#post-137928849
    Plugging the upper hose of the expansion tank would be effective to prevent Air coming into the system?
     
  22. tuttebenne

    tuttebenne F1 Rookie

    Mar 26, 2003
    3,193
    Bay Shore, NY
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    Andy
    I think you should stop modifying a system that should work fine and start finding the cause of your problem. At one point I thought I had a head gasket leak and did the following with the engine cold:

    - Pressurized the entire system (through the reservoir cap opening) to 15lb and checked for leaks.
    - Observed pressure for 1.5 hours. Pressure dropped to 14lb within one minute but held for 1.5 hours. It initially drops because any air in the system is absorbing the air pressure.
    - While under pressure insert a boroscope into each cylinder and inspect for traces of coolant. These are cheap ($35 US)

    If you can pass these tests you can be pretty sure your cooling system is tight and you don't have a head gasket issue.

    Questions: How much coolant did you drain out when you converted to Evans? How much Evans did you have to add to fill the system? My '77GTB holds 5 gallons of coolant.

    Have you observed the behavior of the thermostat in a pot of boiling water? What happens?
    What is the direction of airflow through the radiator when the fans are on? (is air blowing toward spare tire?)
     
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  23. RodC328gts

    RodC328gts Formula Junior

    Aug 17, 2021
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  24. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
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    No, that is the bleed line from the engine. Any air in the system will follow that line to the top of the expansion tank which is where it belongs. The problem with the 308 system is that any air that might get carried forward will be trapped at the top of the radiator. Normally systems like this have a bleed line from the top of the radiator to the top of the expansion tank but the 308 does not. The air trapped in the radiator is what causes the coolant level in the expansion tank to rise and can only be removed manually by opening the bleed screw at the upper RH corner. One good mod is to install a drilled bleed screw at the radiator so that you can let the air out by loosening it and don't have to completely remove it.
     
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  25. Jdubbya

    Jdubbya The $10 Trillion Man
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    Dec 28, 2003
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    I was one of the ones back then advocating for plugging the small hose to the expansion tank. In my experience, my car would puke coolant almost every time after a drive. No matter how well I bled the system it kept doing it. Even after going through many of the steps you have. It still did it. It got to the point that I started parking my car on some wood blocks when coming home and EVERY time before leaving I'd start the car and bleed a pretty good amount of air from the radiator bleed screw. Every time.

    After I bled it again and blocked off that small hose, I never had another problem with getting excess air in the system. That small hose enters the expansion tank well above the level of the water. To my simple way of thinking that was a way, as the car cooled down and the coolant receded it would suck air into the system from the top of the expansion tank.

    All I know is, I was basically told I was wrong but my experience is what it was. I just put a hose clamp on that line near the expansion tank and it solved my problem.

    Now, if air in your system is NOT the problem then you probably have another issue. BUT also.... If it's not puking out coolant after stopping (or while running for that matter), the fans are coming on and it's not getting above 195 on an 80 degree day, I'm not even sure you have a problem. Don't overfill it, bleed it properly, drive it, let it cool and then check where the level is. If it's normal and not overheating or puking coolant all is good.
     
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