Wierd crack in Iron Duke block
12-03-2000, 08:48 PM
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Wierd crack in Iron Duke block
This is a non F-body question, but since some thirdgens had the iron duke motor I figured someone might be able to answer this.
Anyway, I have an '86 S-10 with the 2.5L motor. It has ran great since I got it a year ago, has 132K miles on it, and started using up coolant a few weeks ago, also the temp. seemed to be going higher than normal. I thought the thermostat might be getting stuck, so I replaced that but still had the same problem. It started getting worse, and I also noticed that there was water in the oil. I figured the head gasket went, so I pulled it apart to see if that was the case.
What I found was a mysterious hole in the block's deck surface, in the rear about halfway between the top two bellhousing bolts. There's no matching hole in the new head gasket, or in the head. The irregular shape of the hole doesn't look like something the factory would've included in the block casting. It's like a half-moon shape, 1/" in diameter.
My question is, should that hole be there, and if now, does anyone know how the block could've suddenly failed like that? Could it have been there for a long time, and just now the gasket failed, letting the coolant into the oil passages?
Anyway, I have an '86 S-10 with the 2.5L motor. It has ran great since I got it a year ago, has 132K miles on it, and started using up coolant a few weeks ago, also the temp. seemed to be going higher than normal. I thought the thermostat might be getting stuck, so I replaced that but still had the same problem. It started getting worse, and I also noticed that there was water in the oil. I figured the head gasket went, so I pulled it apart to see if that was the case.
What I found was a mysterious hole in the block's deck surface, in the rear about halfway between the top two bellhousing bolts. There's no matching hole in the new head gasket, or in the head. The irregular shape of the hole doesn't look like something the factory would've included in the block casting. It's like a half-moon shape, 1/" in diameter.
My question is, should that hole be there, and if now, does anyone know how the block could've suddenly failed like that? Could it have been there for a long time, and just now the gasket failed, letting the coolant into the oil passages?
12-04-2000, 12:43 AM
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Car: 91 Red Sled
Axle/Gears: 10bolt Richmond 3.73 Torsen
I'm just going to stab at it and say that it might have been water in the block that just rusted a hole through the deck, then the head gasket eventually gave in.
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, Jon (91 RS too many mods to list)
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, Jon (91 RS too many mods to list)
12-04-2000, 04:40 PM
#3
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flaw in the casting maybe. be a lot of work and expense to fix. might be better to find a differant engine to swap in. if i was going to fix it i'd consider making the hole round and putting a pipe plug in it and machineing it flush. pretty much be talking a rebuild going this far with it. might get by welding it, but still have to machine it.
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-=ICON MOTORSPORTS=-
1st & 3rd
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-=ICON MOTORSPORTS=-
1st & 3rd
12-04-2000, 04:59 PM
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Car: 4
Engine: 6
Transmission: 5
If the head gasket has no hole for it, then it is of no consequence. The factory often casts holes or other shapes in odd places for reasons that have to do only with manufacturing but once the thing is made their purpose disappears.
Where was the actual leak? What you describe doesn't sound like the culprit.
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"So many Mustangs, so little time..."
Where was the actual leak? What you describe doesn't sound like the culprit.
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"So many Mustangs, so little time..."
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