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Anti-freeze leak

michrand

New member
Joined
Apr 2, 2007
Messages
1
Location
massachusetts
Corvette
1985 coupe
Hi All,
I am hoping that someone can help me out. I have a 1985 vette, it was leaking antifreeze from the front of the engine-I figured it was the water pump-I took it to my mechanis that told me he saw antifreeze coming from the water pump vent hole. I replaced the pump myself and guess what, It does the same thing. It seems to me to be coming under the engine but I dont know of any hoses going underneath the car. I looked at the pump and hoses from radiator but neither is wet. The fromt cross member is filled with antifreeze making it difficult to distinguish where the leak is, Any Ideas??? I am going to lift the car and see what I can see from underneath.
Thanks Mike
 

gmjunkie

Well-known member
Joined
Nov 11, 2004
Messages
4,547
Location
Old Fort NC/Vero Beach FL
Corvette
03 Z-51,78 L82 Coupe
Hi All,
I am hoping that someone can help me out. I have a 1985 vette, it was leaking antifreeze from the front of the engine-I figured it was the water pump-I took it to my mechanis that told me he saw antifreeze coming from the water pump vent hole. I replaced the pump myself and guess what, It does the same thing. It seems to me to be coming under the engine but I dont know of any hoses going underneath the car. I looked at the pump and hoses from radiator but neither is wet. The fromt cross member is filled with antifreeze making it difficult to distinguish where the leak is, Any Ideas??? I am going to lift the car and see what I can see from underneath.
Thanks Mike
I'd say it's coming from the Frost Plugs in the side of the block!!! They will rust out over time!!!:upthumbs
 

Notorious

Well-known member
Joined
Oct 9, 2005
Messages
53
Location
Confederate States of America
Corvette
Highly modified '95 A4 coupe
Core plug(s) are a definite possibility. The terms frost plugs or freeze plugs are misnomers. This is not the reason they are installed in your car. They are necessary to plug holes in the block that are required for the casting process. If you count on these to protect your block (if you're too stupid to keep a proper mix of clean antifreeze in your car) then it's only dumb luck if one of these pops out before you crack your block. And they don't necessarily rust out over time. Generally they rust from the inside out due to p*ss-poor cooling system maintenance. This is why we flush the system and change coolant every couple of years, max.
 
R

Robert

Guest
I better check out my 84. It has a slight leak that seems to be coming from passenger's side engine.

I have been worried about it and now more so.
 

karagoz

Member
Joined
Dec 17, 2006
Messages
14
Location
Detroit
Corvette
1988 Red Coupe
Hi All,
I am hoping that someone can help me out. I have a 1985 vette, it was leaking antifreeze from the front of the engine-I figured it was the water pump-I took it to my mechanis that told me he saw antifreeze coming from the water pump vent hole. I replaced the pump myself and guess what, It does the same thing. It seems to me to be coming under the engine but I dont know of any hoses going underneath the car. I looked at the pump and hoses from radiator but neither is wet. The fromt cross member is filled with antifreeze making it difficult to distinguish where the leak is, Any Ideas??? I am going to lift the car and see what I can see from underneath.
Thanks Mike

I own a 1988 and I have replaced my intake manifiold gaskets twice because of coolant leaks. I found puddles of coolant on top of the engine around the intake manifold runners. You might want to investigate this possibility.
 

douglas foster

Well-known member
Joined
Aug 18, 2005
Messages
226
Location
minnesota usa
Corvette
1984 C4 Gold coupe, Z51, 4+3 manual, BBS rims,
father & son

I replaced my cooling system antifreeze on my 84. Replaced thermostat ect:. Had a real problem with the thermstat houseing sealing up. I though that it took a normal type gasket,and a little 3M sealer WRONG!!!!!. I kept haveing leakage around houseing. All the parts people, GM and others, told me my houseing must be bad. Found out that it was the gasket that everyone was selling me was wrong. A NAPA service rep. found a high performance gasket used on other GM eng. it was a little expensive but it worked.
vett4-04.jpg
Good Luck
 

c4cruiser

Well-known member
Joined
Feb 22, 2002
Messages
971
Location
Lacey, WA USA
Corvette
87 Gold Z52 Coupe 02 EB Z51 Supercharged Coupe
If you have an AutoZone parts store near you, you can rent a cooling system pressure tester (the rental is really free; you pay a deposit and when you bring the item back, you get all of your money back).

Pressurize the syystem to 16-18psi and look under the car to see if there are any leaks.
 
Joined
Aug 30, 2002
Messages
1,533
Location
Colorado Springs, CO USA
Corvette
84 Z51 auto R.I.P. 89 black roadster SOLD
I replaced my cooling system antifreeze on my 84. Replaced thermostat ect:. Had a real problem with the thermstat houseing sealing up. I though that it took a normal type gasket,and a little 3M sealer WRONG!!!!!. I kept haveing leakage around houseing. All the parts people, GM and others, told me my houseing must be bad. Found out that it was the gasket that everyone was selling me was wrong. A NAPA service rep. found a high performance gasket used on other GM eng. it was a little expensive but it worked. Good Luck

I've never used anything more than plain 'ol gasket material and cut one out (the good gray/blue stuff, not the crap green stuff)...it's a little thicker than what normally comes with a thermostat.

Oh and that engine bay is WAY too clean! :L

Bill
 

Radar

Well-known member
Joined
Oct 23, 2001
Messages
200
Location
Oconomowoc, WI
Corvette
1989 Medium Blue Metalic Convertible
My 89 will leak few drops of antifreeze over the winter while in storage from November to April. But once I drive it in the summer, never a drop! Never did find the leak. But I suspect an intake amifold gasket issue. I never did find where the leak was either. Some years, it never leaks even over the winter. Go figure.

Good luck. Let us know when you find the culprit!

Regards,
Radar :w
 

polish41

Active member
Joined
Dec 8, 2001
Messages
33
Location
Watertown, SD.
Corvette
former1961,1964,1975.1984 current 1985
I had the same problem. Mine woul leak occasionaly. Finally found the culprit. It was a tiny pinhole in the lower hose. It would leak under pressure but as soon as the pressure was released it would quit. Also the hole was pointed at the lower part of the block making it look like a water pump leak. :crazy
 

86PACER

Well-known member
Joined
Dec 31, 2002
Messages
182
Location
CA
Corvette
1986 Pace Car
-I took it to my mechanis that told me he saw antifreeze coming from the water pump vent hole. I replaced the pump myself and guess what, It does the same thing.

That's why you can't trust a lot of mechanics. You could have paid to have that done, and it would not have fixed jack.

Go borrow the cooling system pressure tool from Autozone. You can then pressurise the cooling system with a hand pump, and check for the leaks. Then tell the mechanic how dumb he is.
 

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