71 gt coolant overflow

luapopel · 08-02-2007

on my 71 gt i just replaced the head since it was warped had a valve job done put new gaskets everywhere and now that i cranked it up after i shut the motor off im still having coolant pushed out of the overflow. Its not compression getting in there since i ran it without the cap on and no air was getting pushed out could it just be a bad radiator cap. I pulled this gt out of a barn thats been sitting for 10 years just looking for any ideas anybody might have. thanks

shade tree · 08-02-2007

Is it overheating?

Mike Preble · 08-02-2007

After a car sits for a long time it is possible for crud in a coolant system to settle and clog parts of a radiator or engine. Also, electrolysis with oxidation can occur and aluminum can turn into aluminum hydroxide (tums) if I remember my chemistry correctly. Parts of coolant system are aluminum. Something to think about. Take radiator to radiator shop to get it flushed and pressure checked, first. Start with the easiest and most productive first.

Mike

luapopel · 08-02-2007

no its not overheating havnt run it long enough to got a bunch of wiring and brakes to do before start driving

shade tree · 08-02-2007

Did it bubble out, like air left in the cooling system after the first fill?

Does it flow good? Radiator plugged?

Take out the thermostat and flush the system with a garden hose untill it runs clear. Try to run it again water only theromostat out see what it does.

luapopel · 08-03-2007

it was just the radiator cap i should have replaced it to begin with but aint got a whole lot of money to play with.

R's opel gt · 08-03-2007

I have a 1972 and replaced the head gasket also, still had issues with coolant blowing out the radiator. Had cyl head checked found it was warped, .18. While having the head milled they found a crack at cyl # 3 from the intake valve to the water jacket. The crack did not show up during a pressure test. not untill they shaved off .14 did it show up :

Now I have a replacement head on order.

luapopel · 08-03-2007

thats what i was worried about but when i run it with the cap off i dont have any pressure coming out. So i looked at it again and the cap wasnt releasing soon enough. I just had the block milled and they didnt find any cracks so im hoping it will be alright. with any luck ill be driving this weekend. Ive had this car waiting around for over 6 months and still havnt drove it i am getting pretty ancy.

Paul · 08-03-2007

Originally Posted by luapopel

I just had the block milled and they didnt find any cracks so im hoping it will be alright.

Did they mill the block or the head? How much did they mill off?

luapopel · 08-03-2007

sorry i meant head and im not sure how much they had to take off but i did check it with a straight edge and it was flat as well as the block im not having any compression leaks ive checked the compression and there all around 155psi. Im goin to rewire it today and actually run it so i know whats goin on with it. It should be ready to go pretty soon

R's opel gt · 08-03-2007

6 MO. ! I bought my 72 a year ago and am about to prime and paint. 1 year restoration, lots of welding and body work. Also rebuilt front and rear susp. Will let you know how it runs when cyl head is reinstalled. Hopefully it will be ready for the National Opel meet in Springfield Il. 9/29

luapopel · 08-03-2007

yea like i said its been waiting around just started working on it last week.

08-02-2007	#1 (permalink)
luapopel Opeler Join Date: Jul 2007 Location: alabama Posts: 29	Unanswered: 71 gt coolant overflow on my 71 gt i just replaced the head since it was warped had a valve job done put new gaskets everywhere and now that i cranked it up after i shut the motor off im still having coolant pushed out of the overflow. Its not compression getting in there since i ran it without the cap on and no air was getting pushed out could it just be a bad radiator cap. I pulled this gt out of a barn thats been sitting for 10 years just looking for any ideas anybody might have. thanks

08-02-2007	#4 (permalink)
luapopel Opeler Join Date: Jul 2007 Location: alabama Posts: 29	gt no its not overheating havnt run it long enough to got a bunch of wiring and brakes to do before start driving

08-03-2007	#6 (permalink)
luapopel Opeler Join Date: Jul 2007 Location: alabama Posts: 29	71 gt it was just the radiator cap i should have replaced it to begin with but aint got a whole lot of money to play with.

08-03-2007	#7 (permalink)
R's opel gt 2 seats is enough Join Date: Jul 2007 Location: Grandville, Michigan Posts: 32	Cyl head I have a 1972 and replaced the head gasket also, still had issues with coolant blowing out the radiator. Had cyl head checked found it was warped, .18. While having the head milled they found a crack at cyl # 3 from the intake valve to the water jacket. The crack did not show up during a pressure test. not untill they shaved off .14 did it show up : Now I have a replacement head on order.

08-03-2007	#8 (permalink)
luapopel Opeler Join Date: Jul 2007 Location: alabama Posts: 29	head thats what i was worried about but when i run it with the cap off i dont have any pressure coming out. So i looked at it again and the cap wasnt releasing soon enough. I just had the block milled and they didnt find any cracks so im hoping it will be alright. with any luck ill be driving this weekend. Ive had this car waiting around for over 6 months and still havnt drove it i am getting pretty ancy.

08-02-2007	#2 (permalink)
shade tree Opeler Join Date: Oct 2004 Location: Michigan Posts: 17	Is it overheating?

08-02-2007	#3 (permalink)
Mike Preble Member Join Date: Jan 2003 Location: Tucson, AZ Posts: 368 Provided Answers: 1	After a car sits for a long time it is possible for crud in a coolant system to settle and clog parts of a radiator or engine. Also, electrolysis with oxidation can occur and aluminum can turn into aluminum hydroxide (tums) if I remember my chemistry correctly. Parts of coolant system are aluminum. Something to think about. Take radiator to radiator shop to get it flushed and pressure checked, first. Start with the easiest and most productive first. Mike

08-02-2007	#5 (permalink)
shade tree Opeler Join Date: Oct 2004 Location: Michigan Posts: 17	Did it bubble out, like air left in the cooling system after the first fill? Does it flow good? Radiator plugged? Take out the thermostat and flush the system with a garden hose untill it runs clear. Try to run it again water only theromostat out see what it does.

08-03-2007	#10 (permalink)
luapopel Opeler Join Date: Jul 2007 Location: alabama Posts: 29	head sorry i meant head and im not sure how much they had to take off but i did check it with a straight edge and it was flat as well as the block im not having any compression leaks ive checked the compression and there all around 155psi. Im goin to rewire it today and actually run it so i know whats goin on with it. It should be ready to go pretty soon

08-03-2007	#11 (permalink)
R's opel gt 2 seats is enough Join Date: Jul 2007 Location: Grandville, Michigan Posts: 32	opel gt 6 MO. ! I bought my 72 a year ago and am about to prime and paint. 1 year restoration, lots of welding and body work. Also rebuilt front and rear susp. Will let you know how it runs when cyl head is reinstalled. Hopefully it will be ready for the National Opel meet in Springfield Il. 9/29

08-03-2007	#12 (permalink)
luapopel Opeler Join Date: Jul 2007 Location: alabama Posts: 29	6 month yea like i said its been waiting around just started working on it last week.

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