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Radiator Overflowing??(Kinda long)

961 Views 3 Replies 2 Participants Last post by  kinnunen
My 289 continues to have radiator fluid coming out of the overflow. It started out to be excessive, I have a new 3 row radiator installed along with a new 195 deg. thermostat. I first replaced the radiator cap with a 13 lb cap, problem decreased considerably. I pulled a compression check on all the cylinders, was between 130-145 lb with #6 at 120 #. A little oil brought #6 up to 145 lbs. Decided to replace the thermostat with a 165 deg one and a new water pump while I was at it. No problem with the old pump was noted. It seemed that my problem went away, no leaks. Please note that I did watch the water flowing in the radiator with the cap off, no bubbles were seen but on one occasion, it did burp out the hole a lot when the thermostat opened up. aLso note that my temperature indicator never went above 1/2 scale, dropped a lot with the lower thermostat. Anyway, driving at 60-70, everything looked good for a couple of weeks until the other day when I was on the divided highway and I cranked it up to 90 for about 10 minutes, at which time I noticed my temperature was very high but still just below the "h". I pulled over and sure enough, about 1 gallon of fluid was blown out of the radiator. I replaced the fluid and drove home. I was wondering that maybe my timing is off enough that I am creating excessive heat at the higher speeds. This has really been driving me crazy for several weeks now. And by the way, I have no real history on the car since buying it and doing a rolling restoration for the last year, I have just been able to get it on the road. Any help would be greatly appreciated. Also, if it helps, I have 3.00 rear end with a C4 auto. Thanks

66 coupe, 289-2v, C4 Auto, Emberglo with Pony interior
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Discussion Starter · #2 ·
With the new rad and all I'd check the timing, ours did about
the same at 70 when we got it and it was timing.
But I don't remember if it was advanced or retarded to much
that caused the problem.

66 Coupe, 289/2v, C4, CA Red

· Supporting Vendor
3,951 Posts
I'll bet your lower radiator hose either has no spring in it or the one
in it is rusted and doesn't keep the hose open at high rpm.
When you are on the highway at a good speed the lower hose
gets suction and if the spring is gone it will collapse the hose and
over-heat the motor. Around town it will run cool because the motor
has time to relax the pressure at stop signs.

Please let us know if this is it. Could help a lot.<P ID="edit"><FONT SIZE=-1>Edited by opentracker on 03/28/01 09:33 PM (server time).</FONT></P>
1 - 4 of 4 Posts
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