Blown head gasket?
Thread Starter
Instructor
Joined: Mar 2005
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From: 86 Z51 Coupe Branson,MO
Blown head gasket?
My temps on the Hiway with both fans constanlty wired on is 235-240.I know this probably isn't normal.No debris in the space between the radiator.The radiator is new and also the waterpump.Around town it will stay around 200.Thermostat is ok also.Also there is no condensor.Please reply,Thanks!
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86 Coupe
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Possibly, but you'll need to pull some plugs and see whats up. Also it should be smoking, white smoke, if theyre fully blown.
The problem could also be that your fans are always on, theyre supposed to shut off when you get up to speed, having them running while youre at 70mph is DETRIMENTAL to cooling, so theyre having the opposite effect.
The problem could also be that your fans are always on, theyre supposed to shut off when you get up to speed, having them running while youre at 70mph is DETRIMENTAL to cooling, so theyre having the opposite effect.
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
For sure sounds high.
Iron heads?
Stock?
How many miles on it?
Any recent engine work? Like with the timing?
Any gurggling under the radiator cap while the engine is running?
Remove the spark plugs and have someone crank the engine. Any moisture being blown out of the holes? Or any puddling in the bores?
Iron heads?
Stock?
How many miles on it?
Any recent engine work? Like with the timing?
Any gurggling under the radiator cap while the engine is running?
Remove the spark plugs and have someone crank the engine. Any moisture being blown out of the holes? Or any puddling in the bores?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Should run close to the thermostat temp on the hwy. You might want to verify the accuracy to the gage. Scan it and compare the dash readout to the coolant temp sensor temperature. If they're not within a couple of degrees, you may just need a new gage sender.
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Don't forget that your inside of your radiator could be getting clogged.
Mine this year was exceeding 210 on the highway - pulled it out and as you reported the outside and small space was free of debris.
Took it to an old guy that races and has a radiator shop, he flushed it out and now on the street I seldom see over 175*. Same radiator, same everything...its just flowing now like it should. Those tubes in there are small, and it doesn't take much to restrict their flow, or coat(insulate the tubing) which all results in higher temps.
Get it cleaned out good and I bet your good to go then.
Mine this year was exceeding 210 on the highway - pulled it out and as you reported the outside and small space was free of debris.
Took it to an old guy that races and has a radiator shop, he flushed it out and now on the street I seldom see over 175*. Same radiator, same everything...its just flowing now like it should. Those tubes in there are small, and it doesn't take much to restrict their flow, or coat(insulate the tubing) which all results in higher temps.
Get it cleaned out good and I bet your good to go then.
Pro
Joined: Jun 2004
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From: Santee Ca
Originally Posted by vader86
The problem could also be that your fans are always on, theyre supposed to shut off when you get up to speed, having them running while youre at 70mph is DETRIMENTAL to cooling, so theyre having the opposite effect.
The fans turning is like putting a piece of wood there. At freeway speeds there should be enough air moving through the radiator to keep it cool.
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Originally Posted by Insane1
The fans turning is like putting a piece of wood there. At freeway speeds there should be enough air moving through the radiator to keep it cool.
The fan blades still only occupy a certain amount of area Turning or not turning, and they are inches away from the radiator...therefore I don't think they would block anything....I have run mine on full time with a fan switch and temps are ALWAYS cooler with them on....granted you should be able to run without them on as mentioned at speed.
But just cause they "look" like a solid piece when they are spinning doesn't mean they are solid and blocking anything.
That and I always thought it made me run quicker, because it was sucking air down the strip, and pushing the air out the back like a jet engine.
j/k
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Thread Starter
Instructor
Joined: Mar 2005
Posts: 217
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From: 86 Z51 Coupe Branson,MO
No engine work.I talked to an "Expert" @ the speed shop today and he said the fans would keep it cooler when on constantly.Temps are definately correct!The radiator is brand new.AS far as the head gasket...The radiator does gurgle!!!Bubbles under the cap when I open it.Any toher tests?Thanks
Pro
Joined: Jun 2004
Posts: 646
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From: Santee Ca
Originally Posted by ski_dwn_it
WHAT? How does that work?
The fan blades still only occupy a certain amount of area Turning or not turning, and they are inches away from the radiator...therefore I don't think they would block anything....I have run mine on full time with a fan switch and temps are ALWAYS cooler with them on....granted you should be able to run without them on as mentioned at speed.
But just cause they "look" like a solid piece when they are spinning doesn't mean they are solid and blocking anything.
That and I always thought it made me run quicker, because it was sucking air down the strip, and pushing the air out the back like a jet engine. j/k
The fan blades still only occupy a certain amount of area Turning or not turning, and they are inches away from the radiator...therefore I don't think they would block anything....I have run mine on full time with a fan switch and temps are ALWAYS cooler with them on....granted you should be able to run without them on as mentioned at speed.
But just cause they "look" like a solid piece when they are spinning doesn't mean they are solid and blocking anything.
That and I always thought it made me run quicker, because it was sucking air down the strip, and pushing the air out the back like a jet engine.
j/kMy circle track car ALWAYS ran cooler and faster without the fan on the track. Trouble is it would overheat on yellow flags and it was also against the rules to run without it. Believe it or not the stock thermal fan performed better on horsepower and cooling then any other setup because when it would freewheel.
Shoot water at a spinning fan and one that is stopped and see which one you can get more water trhough.
Last edited by Insane1; Jul 6, 2005 at 11:38 PM.