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Cooling system problems

Discussion in '308/328' started by thedunk, Sep 7, 2018.

  1. thedunk

    thedunk Rookie

    May 6, 2015
    17
    Claremont, CA
    Full Name:
    Kent Miller
    I live in Southern California so the weather in the summer is hot. I have owned my 1981 308GTSi since 1984 and it has always run well (50k miles). As the years have gone by it has seemed to acquired a problems staying cool. It happened gradually so nothing just broke. My car is pretty much perfect except for the A/C which no longer works so that can't be overheating the car. Now I have to keep it in the garage all summer and I have to be careful with it the rest of the year. I thought it might be the radiator so I ordered a new aluminum one from Nick Forza in Washington. I had it installed and was disappointed to see that there was no improvement. After reading FerrariChat on the cooling system I installed a new lower temp thermostat. No improvement. Any ideas? Do the radiator hoses ever get plugged up? The pump doesn’t seem to be a problem but should I try replacing it anyway? The temp gauge has always worked fine but could the sensor be bad or the gauge itself? Any suggestions?
     
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  3. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    2,931
    Tallahassee, FL
    A lower temp thermostat is of very nominal value.

    Check for leaks. Make sure the fans are running, when they should, and running strong. If they aren't, consider replacing with better more modern units. If the cap is over 5 years old, replace it. Have a look at the water pump.

    There's some basics to start.
     
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  4. miketuason

    miketuason F1 World Champ
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    Feb 24, 2006
    14,321
    Cerritos, CA.
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    Mike
    Are both of the fan on the front rad working?
     
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  5. Nino1964

    Nino1964 Karting
    Silver Subscribed

    Aug 14, 2015
    210
    North Georgia
    How’s the pump?
     
  6. Cuddy K

    Cuddy K Karting

    Oct 30, 2017
    133
    Full Name:
    Ian Karr
    Agree this sounds fan or water pump related.
     
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  8. miketuason

    miketuason F1 World Champ
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    Feb 24, 2006
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    Kent, I sent you PM
     
  9. Baltz1969

    Baltz1969 Karting

    Apr 24, 2017
    57
    Chula Vista, CA
    Full Name:
    Jose Baltz
    Check for air in the system. Elevate the rear of the car & release the air at the water inlet on the top of the right side of the engine.


    Sent from my iPad using FerrariChat.com mobile app
     
  10. thedunk

    thedunk Rookie

    May 6, 2015
    17
    Claremont, CA
    Full Name:
    Kent Miller
    Both fans work fine and turn on when the temp gets up a bit.

    No leaks except when it get really hot it pushes a tiny bit of coolant out the cap.
     
  11. thedunk

    thedunk Rookie

    May 6, 2015
    17
    Claremont, CA
    Full Name:
    Kent Miller
    Don't know about the pump. When you open the cap at startup you can see fluid moving around. Pump does not leak. Is there anything that can break in the pump? Since I am completely stuck I thought I just might change the pump since I don't know what else the problem might be. What else is there, thermostat, pump, clogged hoses, fans, radiator?? I have bled both blender values (one at radiator and one at thermostat).
     
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  13. thedunk

    thedunk Rookie

    May 6, 2015
    17
    Claremont, CA
    Full Name:
    Kent Miller
    I have not tried elevating the rear of the car to bleed the system.
     
  14. thedunk

    thedunk Rookie

    May 6, 2015
    17
    Claremont, CA
    Full Name:
    Kent Miller
    Cap seems fine but maybe I will replace it anyway.
    I must say that it acts the way I would expect it to act if it were not properly bled but I have gone back and fourth (front and back) many times with no change.
     
  15. thedunk

    thedunk Rookie

    May 6, 2015
    17
    Claremont, CA
    Full Name:
    Kent Miller
    to miketuason I am sorry if I am not answering these replies correctly but this is my first time communicating on the site. You said you sent me PM but I don't know what that is??
     
  16. miketuason

    miketuason F1 World Champ
    Silver Subscribed Owner

    Feb 24, 2006
    14,321
    Cerritos, CA.
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    Mike
    Means Private Message, check you Inbox.
     
  17. conan

    conan Formula Junior

    Nov 13, 2011
    369
    Maybe the thermostat is not opening properly. I had the opposite problem on my 328. The thermostat leaked and kept the engine cooler than normal when driving fast. Changing the thermostat made a big difference in that the temp increased rapidly up to normal and stayed there. At standstill the temp increased a bit more until the fans kicked in.

    Another thing to check is the belt tension for the pump. Maybe it is just barely rotating. In this case I would expect some noise from the belt though.
     
  18. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,202
    California SF area
    Full Name:
    Paul
    You say both fans are running, what happens at that point? Does the temperature continue to rise unchecked or does it drop to the point that the fans cycle off?
     
  19. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    2,661
    I would take the water pump belt off and feel the bearings on the pump. Yes, fins can break on water pumps, but that's usually the plastic ones.

    Also, check your ignition timing. Not enough advance can cause a motor to run hot.

    What are the exact temperatures ?
     
  20. Lawrence Coppari

    Lawrence Coppari Formula 3

    Apr 29, 2002
    1,972
    Kingsport, TN
    Full Name:
    Lawrence A. Coppari
    If you drive the car at light load but in a lower gear so that the water pump runs faster do you still get the high temperatures? I have a vehicle, not my 328 GTS, whose temperature gauge would climb under a load at relatively low rpm - like driving up a mountain in top gear. When I shifted to a lower gear the temperature gauge would go back to normal. Water pump belt was not slipping because it was driven by the cam belt. Turned out the pump impeller had been eroded creating too much clearance lowering pump efficiency. New pump solved the problem. Just my experience.....
     
  21. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,676
    San Carlos, CA
    Full Name:
    Mitchell Le
    Change...
    Radiator cap
    Thermostat
    Water pump
    Radiator
    Fans
    Radiator / coolant hoses

    in that order. And make sure no obstruction is found anywhere in the air flow.
     
  22. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    5,841
    TX//Mexico/UK
    Full Name:
    Mike 996
    I suggest you check ta few things before throwing any more money/parts at the problem.

    IS the engine actually running hot? A defective gauge/sender can do this as can a bad electrical connection to either. Check the temp at the thermostat box with a IR temp gun and see how it correlates with the car's gauge. It is unlikely they will match but the car's gauge should follow along with the IR gun as far as temp rise is concerned. Assuming your coolant has a normal amount of antifreeze, up to around 220F on the gun with it pointed directly at the thermostat housing (NOT the nose) and about 2-3 inches away is safe enough but I wouldn't let it get much above that. Obviously, if working properly/fans coming on correctly, it should not get that high. Note that if you have too much antifreeze (more than 50%) in the coolant, it will not perform as well since antifreeze has a much lower cooling capability than water. If someone in the past just added antifreeze every time some coolant was needed, the ratio could be bad.

    Do the air purge thing as folks have mentioned. Air in the system will cause the overheating problem. This can develop over time given the right (wrong) circumstances and can result in having low coolant even though the level in the expansion tank looks OK.

    Water pumps do not stop pumping water - they may leak/need new bearings, etc - but as long as they are turning, they are moving the water. As noted, if the belt is slipping, it normally makes a very loud squealing sound. But check belt tension to be sure. It's possible a belt can be so old/brittle that it slips without squealing but that's not very common. You should be able to examine the belt and determine that. Of course, installing a new belt would eliminate this possibility and, if it hasn't been changed in quite a while, I wouldn't call it wasted money, regardless.

    A lower temp t-stat is not a solution to such problems. All it does is open at a lower temp, it does not change the system's capacity to remove heat. All it can do is slightly delay the overheating.

    As Kcabpilot asked, do the temps drop at all once the fans come on? Does the overheating occur while running down the highway, only in traffic, or any time?
     
  23. Lawrence Coppari

    Lawrence Coppari Formula 3

    Apr 29, 2002
    1,972
    Kingsport, TN
    Full Name:
    Lawrence A. Coppari
    If the water pump is turning it will pump water. But the volume it pumps depends on clearances inside the pump. If the impeller has been eroded, it will pump less.
     
  24. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,202
    California SF area
    Full Name:
    Paul
    I had a thread a few months back titled "Air in the cooling system" that pretty much went through all of this. I bought my car in 2016 and it ran fine, I put 10,000 miles on it in the first year and took it everywhere. Then it slowly began to exhibit this trend of getting hot when I was stuck in traffic and not moving. The temperature would rise above the 195 mark, the fans would come on and it would slowly keep creeping up unless I started moving again at which point it would act normal. I flushed the system and put in new coolant, I replaced the pressure cap then the the thermostat, I put in one of Nick's radiators then one of his water pumps, I replaced all of the coolant hoses but the situation continued to gradually get worse.

    Now, in my case, this was caused by air in the system and - don't panic - I discovered the source was a leaking head gasket at the #4 cylinder. This by no means suggests you have the same problem, just that air in the system causes these symptoms. The other thing I found while doing all this work was that it's somewhat tedious to get all of the air bled out. I know this because I drained about 4 3/4 gallons of coolant into a 5 gallon bucket yet it took only a little over 3 gallons before coolant was overflowing from both bleed screws. There are a lot of discussions on how to bleed this system which holds a whopping 14 liters of coolant but I found that by driving the car any air that is in there will eventually get trapped at the top of the radiator and after multiple drives and bleedings at that point I was able to get it to where it seemed to work perfect. I could let it idle for an hour, the fans would kick on at 195, the temperature would drop and the fans would kick off.

    But again, in my case, as I continued to drive the car air would continue to get introduced into the system so the problem would return unless I bled it out after every drive. And again, I'm not suggesting you have this problem I'm only suggesting that you may need to ensure that you have all the air bled out. In my experience you can do this by just using the bleed screw at the radiator. If you haven't already, get one of the drilled ones so that all you have to do is back it out to bleed the air after a drive. I just used a rag underneath it to catch the coolant as it began to come out after the air was expelled, very easy to do. Remember to keep the heater temperature levers full open during all of this. Until you are certain that you have put 14 liters (almost 5 gallons) of coolant back into your system you can be certain there's still air in there somewhere.

    So start with that and get a new pressure cap if you are spitting coolant out. This has solved the problem for most people. Good luck.
     
  25. thedunk

    thedunk Rookie

    May 6, 2015
    17
    Claremont, CA
    Full Name:
    Kent Miller
    I got very discouraged about this overheating problem and just decided to let the car sit in the garage for a while. The other day I finally decided to work some more on it and did make some discoveries. If I remember correctly the "high startup idle" used to kick off at just a tiny bit above the bottom 140 degree mark. New discovery - Now the meter is reading at the middle line between 140 and 195 (about 168 degrees) when it kicks off. Maybe someone can verify the temp at which the high startup idle kicks off? This suggested to me that the meter was actually reading way too high. Then I did another test. I let the engine heat up until the fan kicks on and checked to see what the meter read. It read at the line half way between the 195 mark and the 250 mark. Again if I remember correctly the fans used to come on around the 195 mark. Again someone might verify that for me?? Since the startup idle, the fans and the engine temp have all different sensors it suggested to me that the problem was in the sensor meter circuit and not in the engine at all. Does that make sense? If what I am remembering is true that means the meter is reading about 1/4 of the meter face high! So my next step was to get a new engine temp sensor. By pure luck I actually found a NOS exact parts matching one on Ebay. I had my mechanic install it since it was so hard to get to. UNFORTUNATELY I STILL GOT THE EXACT SAME BEHAVIOR AFTER THE SENSOR REPLACEMENT. So it wasn't the sensor. Does that mean the meter is bad?? Do I send it to someone for testing and calibration? Some years ago I sent my clock to Palo Alto Speedometer for repair. They supposedly work on Ferrari instruments. The quartz clock replacement cost me a lot of money and the clock stopped working a few months ago. Can a temp gauge be checked "out of the car"? Can a temp gauge be calibrated? I have pulled the dash and things look tight, clean and in order. Does anyone have a place to send things like this for repair? Any other ideas? Are the temps that I remember for the startup idle and fan turn on correct?
     
  26. conan

    conan Formula Junior

    Nov 13, 2011
    369
    One option is to heat water in a bowl and measure a few data points with a thermometer. Simultaneously have the sensor body in the water with the connector part out of the water. Of course you need a ground wire between sensor body and vehicle ground.
     
  27. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    2,931
    Tallahassee, FL
    My idle shifts to "warmed up" around 175F. Fans kick on at around 195F.
     
  28. Crowndog

    Crowndog F1 Veteran
    Rossa Subscribed

    Jul 16, 2011
    7,038
    Fairfield,Pa
    Full Name:
    Robert
    Check out this thread. I think you might find it useful; (type in search)

    Automatic Bleeder Valves for your Cooling System!


    Sent from my iPhone using FerrariChat.com mobile app
     

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