Cracked head rather than blown head gasket?

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Old 07-29-10, 04:40 PM
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Cracked head rather than blown head gasket?

For my parked 90 Dodge spirit 4-banger that I have treated you guys to epistles on--------------, I am thinking about raising this car from the dead.

Remember how I barely made it home, some months back?, and yet was able to get it home by stopping about 3 times and adding about 2 gallons of coolant? And how I discovered when I pulled plug #1, that the cylinder was quite full of coolant? And how it billowed steamy smoke?

Well, the other day I decided to drain down the coolant and see how it would run without coolant pouring into the cylinder. It ran like a top! So yesterday morning I decided to pull all the plugs and do a compression test on the car that has in the low 200's of thousands of miles. Well, actually first I shown a light into each cylinder to make sure I was not going to get a false high reading from oil, coolant or carbon in any of the cylinders. No, I can actually see aluminum colored piston tops!

The readings were: #1, 128(bad cylinder) - 2, 155 - 3, 158 - 4, 148. I was amazed at not only a the high readings but at the bad cylinder. I would think that a 'blown head gasket that would allow coolant to pour in, would be more like 0-70.

So I got thinking that maybe it has a crack above the valve, so that when the valve closes there is no air escape. And when it runs, everytime the valve opens, coolant can pour in. Nice theory eh? Just a theory and not likely, or do these Dodges have any history of such cracks? Especially with a Mexican replacement head (which is what it has on it).
 
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Old 07-29-10, 04:46 PM
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No clue on the question...but hey, ecman...where ya been for the last 2 months?
 
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Old 07-29-10, 05:44 PM
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Originally Posted by Gunguy45 View Post
No clue on the question...but hey, ecman...where ya been for the last 2 months?
A combination of working more hours/making more money, catching up on personal things, looking after a sick dad - and taking a vacation from being a know- it- all.

I needed the break. The one-post one thing---posting to cyberspace, sometimes - was getting to me also. But then, I also miss my fellow regular posters here.
 
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Old 07-30-10, 07:03 PM
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Did you try that compression test after engine was warmed up ? Also, make sure engine ran long enough to build up pressure in cooling system. May be compression and heat from cylinder(s) entering cooling system. It certainly wasn't uncommon for them to crack when overheated. Try a pressure gauge on rad, and see if it builds up during running.
 
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Old 08-01-10, 10:55 AM
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Originally Posted by Mike.B View Post
Did you try that compression test after engine was warmed up ? Also, make sure engine ran long enough to build up pressure in cooling system. May be compression and heat from cylinder(s) entering cooling system. It certainly wasn't uncommon for them to crack when overheated. Try a pressure gauge on rad, and see if it builds up during running.
The vehicle only was warmed up enough for me to idle it for a very short bit and then drive it into the garage and shut it off. The plugs were quite warm though when I grabbed them.

What is the idea of checking the coolng system/radiator? Because it has already been stated in my previous thread about my head gasket woes, that a lot of bubbling was going on in the reservoir, even when the car is first started.
 
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Old 08-03-10, 07:50 AM
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I'm working from memory, but I believe these heads had a systematic problem with cracking between the valve seats. It's a thin area that gave problems. You may want to verify this on the Allpar web site.
 
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Old 08-08-10, 02:42 PM
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Thanks Kestas ..........................................
 
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