OVERHEATING - blowing out coolant

Bru · 01-05-2020, 05:10 PM

Are you seeing a cloud of white smoke on start up or while running? Burning coolant it looks like that. Burning oil looks more gray. A crack in the head can allow compression / combustion gases into the water jacket. It's $50 well spent to have it checked at a machine shop that can perform a magnaflux type dye test even though the head is aluminum. The head should be completely disassembled including valves removed. There are also do it yourself preparations on the market. Here is a YouTube page with various methods. https://www.youtube.com/results?sear...lux+head+test+

1bigdoggie · 01-05-2020, 07:54 PM

No white smoke at start up. Seeing blue and gray smoke. I believe that is oil. The original reason I took in the car. Had valve seal leak. So had a new head put on. Solved the oil leak smoking problem at start up, but over heated the very next day. Blown HG. Replaced. Over heated the very next day. Could over heating have cracked the block? The question is WHY did it overheat in the first place, after a head replacement. All was good with the car for 30 years besides the oil leak in the valve seals. Anyway, shop talked me into a replacement engine. Very first day it over heated as well. And I've been here ever since. How can it be that TWO blocks are cracked ? I don't think that is the issue. Oh, and the replacement engine now blows smoke (oil leak) upon start up, which is why I had the head replaced in the first place.

Anyway, will do the leak down test to check the integrity of the HG. I'm really hoping it is that. Because if not, we are basically out of ideas. Will not be able to tear the car apart and get the block checked for cracks. But MAY be able to check the OLD block for cracks. If no cracks in it, then the overheating is caused by something else.

Bru · 01-06-2020, 04:05 AM

Here are pictures of a block that has rot around the cooling passage right up to the fire ring where the gasket seals and a picture of a block in good shape. It's easy to see the difference. As far as cracking goes, the head is more at risk than the block because aluminum is a softer metal than iron.

01-06-2020, 04:05 AM	#3
Bru Bone Stock w Upgrades ;-) Join Date: Apr 2010 Location: Tampa Bay Posts: 211	Here are pictures of a block that has rot around the cooling passage right up to the fire ring where the gasket seals and a picture of a block in good shape. It's easy to see the difference. As far as cracking goes, the head is more at risk than the block because aluminum is a softer metal than iron. Attached Thumbnails

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01-05-2020, 05:10 PM	#1
Bru Bone Stock w Upgrades ;-) Join Date: Apr 2010 Location: Tampa Bay Posts: 211	Are you seeing a cloud of white smoke on start up or while running? Burning coolant it looks like that. Burning oil looks more gray. A crack in the head can allow compression / combustion gases into the water jacket. It's $50 well spent to have it checked at a machine shop that can perform a magnaflux type dye test even though the head is aluminum. The head should be completely disassembled including valves removed. There are also do it yourself preparations on the market. Here is a YouTube page with various methods. https://www.youtube.com/results?sear...lux+head+test+

01-05-2020, 07:54 PM	#2
1bigdoggie Stock Join Date: Dec 2019 Location: californi Posts: 5	No white smoke at start up. Seeing blue and gray smoke. I believe that is oil. The original reason I took in the car. Had valve seal leak. So had a new head put on. Solved the oil leak smoking problem at start up, but over heated the very next day. Blown HG. Replaced. Over heated the very next day. Could over heating have cracked the block? The question is WHY did it overheat in the first place, after a head replacement. All was good with the car for 30 years besides the oil leak in the valve seals. Anyway, shop talked me into a replacement engine. Very first day it over heated as well. And I've been here ever since. How can it be that TWO blocks are cracked ? I don't think that is the issue. Oh, and the replacement engine now blows smoke (oil leak) upon start up, which is why I had the head replaced in the first place. Anyway, will do the leak down test to check the integrity of the HG. I'm really hoping it is that. Because if not, we are basically out of ideas. Will not be able to tear the car apart and get the block checked for cracks. But MAY be able to check the OLD block for cracks. If no cracks in it, then the overheating is caused by something else.