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Help! Coolant leak from the BACK of the engine somewhere!

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Old Feb 12, 2007 | 10:19 AM
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Default Help! Coolant leak from the BACK of the engine somewhere!

I have a bad coolant leak that's dripping down to the oil filter. It appears to be coming from the back of the block somewhere.

Just rebuilt the entire engine. Did I forget to install something? Help!
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Old Feb 12, 2007 | 10:22 AM
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Did you check the crossover tube fittings on the back of each head? There's a little o-ring that need to be under each fitting.
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Old Feb 12, 2007 | 10:32 AM
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but there isn't a crossover tube on the back right? Just the front?
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Old Feb 12, 2007 | 10:41 AM
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You have to block off the 2 fittings on the back of the heads or it will leak bad. The hole look just like the holes on the front of the heads where the crossover is used.
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Old Feb 12, 2007 | 11:37 AM
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I'll check it over tonight. If that's the case, would it make sense that the leak gets worse after driving it?

Also, if that's NOT the case, what else could it be? Surely it wouldn't be a cracked block/head? I guess it could be a blown head gasket, but I JUST rebuilt the engine and replaced EVERY seal/gasket in it.....
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Old Feb 12, 2007 | 12:09 PM
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I'd bet on the coolant vent plugs in the back. The reason it gets worse after driving is because the thermostat opens up and fluid starts to flow.

If it's not that, it may be a head gasket, but it would have to be installed wrong in a big way lol.
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Old Feb 12, 2007 | 12:10 PM
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I also say it's the gasket that goes in the block offs located at the rear of the block.
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Old Feb 12, 2007 | 12:26 PM
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Does it look like this? MS paint rocks! haha

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Old Feb 12, 2007 | 01:28 PM
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ttt!!
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Old Feb 12, 2007 | 03:44 PM
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ttt!! Just looking for more ideas! Thanks!
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Old Feb 12, 2007 | 05:38 PM
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UPDATE - The leak appears to be coming from the area directly above the oil filter... Wonder if it could be a freeze plug
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Old Feb 12, 2007 | 05:39 PM
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JL calm down bro. Send me a pic to jmws6@hotmail.com Ill look at it. Either you forgot to put the block off on the back of the head or the plug in the side of the block.
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Old Feb 12, 2007 | 07:00 PM
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Originally Posted by JLSain
Does it look like this? MS paint rocks! haha

Yes, the gasket is supposed to fit through that nipple (hehe).
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Old Feb 12, 2007 | 07:03 PM
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Originally Posted by JMBLOWNWS6
JL calm down bro. Send me a pic to jmws6@hotmail.com Ill look at it. Either you forgot to put the block off on the back of the head or the plug in the side of the block.
Get on aim sometime bro. I'll PM you my aim name incase you deleted it. It'd be nice to talk to ya.

It's gotta be the plug in the side of the block.

Weird thing is, the leak wasn't there for the first 20 minutes of run time. Once we started putting the transmission in, we noticed the leak. It was very small at first. After driving the car for 15 miles, the leak is now a smal, steady stream.
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Old Feb 12, 2007 | 07:38 PM
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I called no answer dork!
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Old Feb 13, 2007 | 12:05 AM
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830 number? LMAO. I thought it was a bill collector!! LMAO
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Old Feb 13, 2007 | 01:50 PM
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Anyone know what the GM part number is for a freeze plug?
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