Corvette Action Center - The ultimate online hub of Corvette news and information! Click here to go to the Corvette Forums!


Supporting Vendors / Dealers - Supporting Membership - Advertising Information - Corvette Amazon Shop
Results 1 to 15 of 15
Like Tree2Likes
  • 1 Post By gmjunkie
  • 1 Post By air1jpg

Thread: Radiator fluid does not return from recovery tank

  1. #1
    Member air1jpg's Avatar
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    394
    Corvette(s)
    1996 Polo Green LT1 Coupe

    Default Radiator fluid does not return from recovery tank

    Radiator fluid does not return from recovery tank after engine cools down after engine shutdown. I have replaced the radiator cap, what else could cause this? Eventully, the low coolant light will come on after a few days.

  2. #2
    Technical Writer for Internet & Print Media
    Join Date
    Jan 2001
    Location
    Southern California
    Posts
    6,519
    Corvette(s)
    71 95 04 12

    Default

    When the low coolant light comes on is the overflow bottle full?

    If not, the engine is using coolant. If there are no leaks, test the engine for a blown head gasket.

  3. #3
    Member air1jpg's Avatar
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    394
    Corvette(s)
    1996 Polo Green LT1 Coupe

    Default

    Quote Originally Posted by Hib Halverson View Post
    When the low coolant light comes on is the overflow bottle full?

    If not, the engine is using coolant. If there are no leaks, test the engine for a blown head gasket.
    The overflow bottle is full. I also have not noticed any abnormal white exhaust.

  4. #4
    Member
    Join Date
    Dec 2008
    Location
    texas
    Posts
    1,882
    Corvette(s)
    87 z-51

    Default

    Quote Originally Posted by air1jpg View Post
    The overflow bottle is full. I also have not noticed any abnormal white exhaust.
    There is an air leak somewhere...or water leak.

    The radiator as it cools creates a vacume inside that draws water from the recovery tank back into the radiator...as it should work.

    If that vac (which is small) is not there, coolant cannot make the return trip and it will keep escaping under pressure...which suggest, under normal conditions there should NOT be much, if ANY coolant going into the tank. Thats there for boil-over capture or very hot days. The only other way it can push coolant out of the radiator and into the recovery tankwhen its not extremely hot, is by pressurizing the radiator with exhaust or compression from a blown head gasket.

    When its stone cold, start the car and go remove the radiator cap. if there is pressure in there, you have problems. If there are bubbles in there, same problem just more evidence now.

  5. #5
    Gone but not forgotten John Robinson's Avatar
    Join Date
    May 2005
    Location
    Muncie, Indiana
    Posts
    1,609
    Corvette(s)
    1993 Polo Green Coupe

    Default

    Besides the head gasket theory you could also have a leaking water pump which would have the same results as a leaking head gasket or a very small pin hole in one of the radiator hoses. You don't say but when you run the heater do the windows inside the car fog up (if so bad heater core) All of which would do what a blown head gasket would do. You could take the car to some place like Advance Auto Parts and have them do a pressure check on the system which would include pressure checking the new radiator cap to be sure it is good. What you are looking for is evidence of were the hole is so do a visual inspection around all of the hoses etc for the tell tale stain antifreeze leaves when it leaks out.

  6. #6
    Technical Writer for Internet & Print Media
    Join Date
    Jan 2001
    Location
    Southern California
    Posts
    6,519
    Corvette(s)
    71 95 04 12

    Default

    Quote Originally Posted by air1jpg View Post
    The overflow bottle is full. I also have not noticed any abnormal white exhaust.
    Sorry. I asked the wrong question.

    Is the overflow bottle at the "full" mark or is it full to overflowing out its vent?

    If the bottle is truly overflowing, then the coolant is not being taken back into the system after expansion forces it out. If the bottle is simply "full" but the coolant light comes on periodically, then the engine is using coolant and I'd take John Robinson's advice and have the system tested.

  7. #7
    Member tmkassin's Avatar
    Join Date
    May 2009
    Location
    Macomb,MI
    Posts
    270
    Corvette(s)
    2009 LS3

    Default

    It is possible that the recovery tank is dirty and plugging the return line. When the car has cooled down remove the tank and wash it out with mild detergent.

  8. #8
    Member air1jpg's Avatar
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    394
    Corvette(s)
    1996 Polo Green LT1 Coupe

    Default

    Quote Originally Posted by Hib Halverson View Post
    Sorry. I asked the wrong question.

    Is the overflow bottle at the "full" mark or is it full to overflowing out its vent?

    If the bottle is truly overflowing, then the coolant is not being taken back into the system after expansion forces it out. If the bottle is simply "full" but the coolant light comes on periodically, then the engine is using coolant and I'd take John Robinson's advice and have the system tested.
    Before I replaced the radiator cap, it was full too the top of the tank. The last time I checked, it was full to close to the top of the tank. I am going to have the system pressure checked here soon after I get my truck back from Ford.

  9. #9
    Member air1jpg's Avatar
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    394
    Corvette(s)
    1996 Polo Green LT1 Coupe

    Default

    The heater works good and I have no fog on the windows. The engine idles and runs good with no white exhaust from the tail pipe.

  10. #10
    Member gmjunkie's Avatar
    Join Date
    Nov 2004
    Location
    Old Fort NC/Vero Beach FL
    Posts
    5,313
    Corvette(s)
    03 Z-51,78 L82 Coupe

    Default

    Quote Originally Posted by air1jpg View Post
    The heater works good and I have no fog on the windows. The engine idles and runs good with no white exhaust from the tail pipe.
    Check the hose and aluminum line that go's from expansion tank to reservoir, It's got a crack sucking air!~!!(Probly where it's attached to the Expansion Tank!~!!)
    Janice likes this.
    junk!!
    "WARNING"
    The views and opinions of this forum user might not be suitable for others, this user may appear to be heavily over-medicated, under medicated, intoxicated, listening to the voices in his head or just plain being an ass, so some viewers may be offended!~!!!
    www.gmjunkie.com
    Founding Member: 10 Corvettes Anonymous


  11. #11
    Technical Writer for Internet & Print Media
    Join Date
    Jan 2001
    Location
    Southern California
    Posts
    6,519
    Corvette(s)
    71 95 04 12

    Default

    Quote Originally Posted by air1jpg View Post
    Before I replaced the radiator cap, it was full too the top of the tank. The last time I checked, it was full to close to the top of the tank. I am going to have the system pressure checked here soon after I get my truck back from Ford.
    We're having a nomenclature problem here...happens sometimes with diagnosis via Internet.

    I was asking about the overflow bottle not the high-fill bottle. The overflow bottle is up in front of the right front tire. The high-fill bottle is to the right-rear of the engine and has the radiator cap.

    Let us know what the pressure check reveals.

    If the cap is defective, the overflow bottle may fill up and eventually overflow because the system is venting coolant into the overflow but not taking it back in.

  12. #12
    Moderator KANE's Avatar
    Join Date
    Mar 2002
    Location
    KY
    Posts
    3,332
    Corvette(s)
    Dark Blue 1982 Trans Am(s): Polo Green 1995 MN6

    Default

    Jon-

    What about the cap- are you losing pressure due to a bad radiator cap?

    EDIT- I just saw that you replaced the cap. Hmmm...

    Is your temp sensor bad on your water pump? If yes- it could be running hotter than you think it is and therefore not showing on your gauge. I had to replace the sensor on my LT1 a few weeks ago. My tank was getting filled as well- due to running hotter than showing.

  13. #13
    Member air1jpg's Avatar
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    394
    Corvette(s)
    1996 Polo Green LT1 Coupe

    Default

    Quote Originally Posted by KANE View Post
    Jon-

    What about the cap- are you losing pressure due to a bad radiator cap?

    EDIT- I just saw that you replaced the cap. Hmmm...

    Is your temp sensor bad on your water pump? If yes- it could be running hotter than you think it is and therefore not showing on your gauge. I had to replace the sensor on my LT1 a few weeks ago. My tank was getting filled as well- due to running hotter than showing.
    Turns out, that the generic replacement radiator cap I bought from Advanced auto was a crap. I bought a OEM cap from a Chevy dealer and it made a world of difference. The fluid level in the recovery bottle is now constant. But now I think I have a new problem. I now occasionally have a strong antifreeze odor inside the car and can see vapor comming out of the vents. I think my heater core is going out, does this sound right? Could some anti-freeze be entering the vents due to a worn heater core, but not be bad enough to allow fluid to dump onto the floorboard?
    KANE likes this.

  14. #14
    Gone but not forgotten John Robinson's Avatar
    Join Date
    May 2005
    Location
    Muncie, Indiana
    Posts
    1,609
    Corvette(s)
    1993 Polo Green Coupe

    Default

    I think you already know what is going on with the new problem. Sometimes with closed high pressure systems when you fix one thing it forces the pressure to the next weak spot. So be prepared to not only replace the heater core but the next thing to go could be a hose or the radiator. I certainly hope that is not what happens to you but it has been my experience in the past.

  15. #15
    Member air1jpg's Avatar
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    394
    Corvette(s)
    1996 Polo Green LT1 Coupe

    Default

    Quote Originally Posted by John Robinson View Post
    I think you already know what is going on with the new problem. Sometimes with closed high pressure systems when you fix one thing it forces the pressure to the next weak spot. So be prepared to not only replace the heater core but the next thing to go could be a hose or the radiator. I certainly hope that is not what happens to you but it has been my experience in the past.
    Thank you for your input. My upper and lower radiator hoses are soft so they will be replaced soon after the core is replaced.

Similar Threads

  1. Coolant Spill from Recovery Tank --(Repost with additional info) Any Idea Why?
    By cajuncorvette in forum C4 Technical and Performance
    Replies: 3
    Last Post: 11-28-08, 03:13 AM
  2. Excess Fluid In The Coolant Reserve Tank
    By EOLIVER in forum C4 Technical and Performance
    Replies: 2
    Last Post: 11-27-04, 05:25 PM
  3. Radiator Surge Tank
    By 1BAD92VETTE in forum C4 Technical and Performance
    Replies: 6
    Last Post: 03-08-04, 06:35 PM
  4. replacing fuel return pipe over gas tank (78 Vette)
    By Nigel_Aves in forum C3 Technical and Performance
    Replies: 2
    Last Post: 07-15-03, 09:13 PM
  5. Radiator tank cracked
    By jsinga in forum C4 Technical and Performance
    Replies: 2
    Last Post: 04-27-02, 06:13 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© CORVETTE is a registered trademark of the General Motors Corporation & Chevrolet Motor Division.  Neither Chevrolet Motor Division nor any subsidiaries of GM© shall bear any responsibility for CorvetteActionCenter.com content, comments, or advertising. CorvetteActionCenter.com is independent from GM© and is not affiliated with, sponsored or supported by GM©.  Copyright/trademark/sales mark infringements are not intended, or implied.  All Rights Reserved