have you ever herd this?
Thread Starter
Instructor
Joined: Feb 2002
Posts: 152
Likes: 0
From: margate florida
have you ever herd this?
first let say may 70 BB is over heating i think. the temp gauge hits 180 i can see water flow in the over flow tank. the stat is new. it will climb to 200 and seems to stay right on 200 i shut the car off and :U out the over flow . the cap is new.i'm not sure what i'm going to do next fan clutch,rod the rad at rad shop, or flush the rad my self.
some one told me i could have a bown head gasket and the pressure from the engine could be the cause of the :U . could this be true ? and how can i check. should i be get :U at 200 that does not seem to hot for a BB.
jim
some one told me i could have a bown head gasket and the pressure from the engine could be the cause of the :U . could this be true ? and how can i check. should i be get :U at 200 that does not seem to hot for a BB.
jim
Burning Brakes
Joined: Dec 2000
Posts: 795
Likes: 0
From: Madison MS
Re: have you ever herd this? (1970LS6)
If you blew a head gasket at a point where you would get compression in the cooling system, you would also be blowing water out of the exhaust. Compression would leak into the cooling system on compression and power strokes but water would flow into the cylinder on the intake stroke. It sounds like you have just lost some efficiency. Could be clogged radiator, missing shroud, etc. It could also be a damaged/missing front chin spoiler. If all the parts are there, I would have the radiator rodded out or replace with an aluminum unit.
dl
dl
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: have you ever herd this? (1970LS6)
Mine did almost the same thing when I first got it except it wasn't running quite as warm. It just kept blowing water from the surge tank. My car had a flex type universal upper radiator hose. The problem is the wrong(or wrong routing) of the upper radiator hose. You need the one with a "U" shaped trap and the trap must go down in front of the alternator. Without this trap, or if it is installed wrong the highest point of the system is the upward hump in the hose where it goes over the alternator. The highest point of the system must be the cap so AIR can vent when pressure gets above the setting on the cap.(15lbs.) If the highest point is anywhere else, the air being lighter than water goes to the highest point and WATER, not air is forced out of the pressure cap. I know it sounds crazy but that's the way it works. That is the reason GM designed the hose with that strange "U" shape.
[Modified by silvervetteman, 5:32 PM 8/1/2002]
[Modified by silvervetteman, 5:32 PM 8/1/2002]
Race Director
Joined: Dec 2000
Posts: 10,896
Likes: 2
From: CO
Re: have you ever herd this? (silvervetteman)
My SB runs right about 195-200 and stays there. I think that would be normal or acceptable temperatures.
If there is too much coolant in the rad then it will over flow.. this is also normal.
A friend of mine had just got his mustang on the road and we went for a cruise. He just filled the rad up and it was sprayin everywhere when we pulled over to check the engine. I was a little worried at first but after driving for a while the tank equalized and all was good. So it may not be as big of a problem as you think.
Does the coolant level drop drastically because of all the :U ing? Keep an eye on the temp and if it stays at 200 drive it. Just my .02 :cheers:
[Modified by flood, 4:46 PM 8/1/2002]
If there is too much coolant in the rad then it will over flow.. this is also normal.
A friend of mine had just got his mustang on the road and we went for a cruise. He just filled the rad up and it was sprayin everywhere when we pulled over to check the engine. I was a little worried at first but after driving for a while the tank equalized and all was good. So it may not be as big of a problem as you think.
Does the coolant level drop drastically because of all the :U ing? Keep an eye on the temp and if it stays at 200 drive it. Just my .02 :cheers:
[Modified by flood, 4:46 PM 8/1/2002]
Racer
Joined: Apr 2002
Posts: 336
Likes: 0
From: Lafayette, Indiana
Re: have you ever herd this? (1970LS6)
I made the mistake of taking my 78 to a radiator shop without checking the fan clutch. I had replaced the water pump, radiator cap, and thermostat, and was still over heating. Radiator was fine but the fan clutch was shot. I could have replaced that myself much cheaper.
The clutch is easy to check. If you would like I will post the instructions from my '68 thru '82 Haynes manual.
The clutch is easy to check. If you would like I will post the instructions from my '68 thru '82 Haynes manual.
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: have you ever herd this? (flood)
Big Blocks being taller creates the hose problem I spoke of earlier. If there is a high spot above the cap, the system will continue to vent water no matter what the level is in the tank. Air expands more than water so each time it vents the amount of air in the system gets greater and you have a never ending circle. More air pushes more water out .....This is an often overlooked thing so check it out. My car runs 180deg. most of the time(with A/C on and in 90deg+ weather) and will get to 210deg after I get off of the expressway but then cools right back down to 180. I very rarely add water now that the system is working correctly and doesn't :U water every time I shut it off. I can't ask for anything better for 33 year old technoligy .
[Modified by silvervetteman, 6:54 PM 8/1/2002]
[Modified by silvervetteman, 6:54 PM 8/1/2002]
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Race Director
Joined: Jan 2000
Posts: 16,489
Likes: 25
From: USA. Northern Virginia
Re: have you ever herd this? (silvervetteman)
Mine did it the first year I had it. That winter I pulled the rad and had it clean and pressure tested...found two leaks...easy fix.
When I put it back in I used 50/50 mix on the anti freeze and added two bottles of Red Line water wetter....never had a problem after that.
Hope this helps, Larry :cool:
When I put it back in I used 50/50 mix on the anti freeze and added two bottles of Red Line water wetter....never had a problem after that.
Hope this helps, Larry :cool:
Pro
Joined: Mar 2002
Posts: 511
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From: St. Louis MO
Re: have you ever herd this? (dladd74roadster)
If you see a constant stream of bubbles running into the overflow tank your head gasket(s) could be blown. Had this happen on a buddies mustang after installing a new set of heads. The factory replacements couldn't handle the .5 increase in compression. Go figure its a ford. But anyway, the only problem from the blown head gaskets was that it was pushing the water out via the overflow. It would take a good hour of driving before the car would over heat. But the entire time you could watch it push air out the overflow. We changed the thremostat, then removed the middle of the thermostat to just leave a small restriction, then had the radiator cleaned professionally, but it finally ended up leaving us no choice but to take the heads off that had only been on for about 2 months. Anyway, just thought I would let you know that even though there isn't any water coming out the exhaust you could still possibly have a head gasket problem.