Rear of the block Intake Leak
It's not the gasket. To the best of my knowledge/experience, the proximity of the EGR tube to this area, subjects the RTV to an excessive amount of heat, and "bakes" the sealing ability out of the RTV.
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From: Little Rock, AR
I'm pretty sure he was referring to "gasket" as the RTV on the back. IDK, for whatever reason it does not seem to be bothering mine.
Cut up pencils for dowels, thats actually a great idea. I have a mysterious oil leak that im hoping is from me putting the intake on wrong, or just not using enough sealant. Everytime i want to feel back there though the engine is hotter then hell lol.
Dont be like me, I sold an M6 car that needed an intake manifold gasket. After doing one myself on this car i am not happy lol. Its way to easy to do this fix. Get a fuel line disconnect and some sockets. Tons of people and websites have write ups on this. The part that was the hardest for me was getting to some of the bolts when alt brackets and all the egr/emissions crap in the way. I got rid of it all and now its as easy as putting the socket on the bolt and turning it with a ratchet (yea...that easy!)
Dont be like me, I sold an M6 car that needed an intake manifold gasket. After doing one myself on this car i am not happy lol. Its way to easy to do this fix. Get a fuel line disconnect and some sockets. Tons of people and websites have write ups on this. The part that was the hardest for me was getting to some of the bolts when alt brackets and all the egr/emissions crap in the way. I got rid of it all and now its as easy as putting the socket on the bolt and turning it with a ratchet (yea...that easy!)
Are you talking about the clearance between the intake and the front and rear of the block? Is it supposed to be a gap between the intake and the block? On my set up, there isn't any gap; the intake sits directly on top of the block. Anyone have any pictures?
Unless your block or cylinder heads have been machined as some part of a rebuild, there IS a gap between the bottom surface of the intake manifold and the top surface of the engine block. It's not a big gap, maybe only .015-.020", but a gap nontheless. It has to be sealed, otherwise crankcase pressure will force oil out....
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From: CT/NJ
Guys, every V type engine with china walls sealed with RTV will eventually leak. This isn't an LT1 problem or an EGR problem or a PCV problem or any such silliness. As the engine heat cycles, it expands and contrats causing relative movement between the intake and the block. Combine this with a seal that continues to vulcanize over time and what you get is a seal that is guaranteed to fail once the sealant is hard enough and it tears instead of stretching.
Guys, every V type engine with china walls sealed with RTV will eventually leak. This isn't an LT1 problem or an EGR problem or a PCV problem or any such silliness. As the engine heat cycles, it expands and contrats causing relative movement between the intake and the block. Combine this with a seal that continues to vulcanize over time and what you get is a seal that is guaranteed to fail once the sealant is hard enough and it tears instead of stretching.
Guys, every V type engine with china walls sealed with RTV will eventually leak. This isn't an LT1 problem or an EGR problem or a PCV problem or any such silliness. As the engine heat cycles, it expands and contrats causing relative movement between the intake and the block. Combine this with a seal that continues to vulcanize over time and what you get is a seal that is guaranteed to fail once the sealant is hard enough and it tears instead of stretching.
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From: CT/NJ
I'm sure you will tell me how the internet knows I'm wrong now and I must be making it all up so, come on with it.
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From: CT/NJ
I agree....to a point. The close proximity of the EGR valve and its feed tube, impart more heat to that area of the block/manifold interface. In case you think I'm nuts, consider this...How many complaints do you hear about the leak being in the FRONT of the engine, which has the exact same manifold/block interface.....minus the EGR heat.
So this vulcanization theory is based on a test that didn't replicate actual use conditions with no documented completion or results to speak of in a building that has been knocked down?
I don't mean to bash, but that sounds pretty ridiculous.
I don't mean to bash, but that sounds pretty ridiculous.
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Joined: Feb 2006
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From: CT/NJ
That's fine. I'm not saying you have to believe me. Google "rubber aftercure" if you would like to learn more.
Before car message boards really existed there were groups of those who race and work on their cars. This problem was one of the most popular and notorious problems of the LT1 when it first came out. Some people even having problems right off the show room floor. As explained in my previous post, a lot of theories came about and the problem was easily remedied by cleaning, applying an ample amount of sealant and letting sealant cure for a long time (sometimes up to 24 hours depending on climate). It worked. Manifolds galore would not leak. For years and years.
I think your theory has merit for sealant that has been properly applied and has been on the car and been exposed to many different elements over a very long period of time, however for you to come in here and pompously claim you have the definite answer with your amazingly lacking experiment is ludicrous.
Because it is. It's just another hack trying to reinvent the wheel.
I think your theory has merit for sealant that has been properly applied and has been on the car and been exposed to many different elements over a very long period of time, however for you to come in here and pompously claim you have the definite answer with your amazingly lacking experiment is ludicrous.
Because it is. It's just another hack trying to reinvent the wheel.
Last edited by SS RRR; Sep 16, 2011 at 07:28 PM.
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Joined: Feb 2006
Posts: 1,025
Likes: 1
From: CT/NJ
Before car message boards really existed there were groups of those who race and work on their cars. This problem was one of the most popular and notorious problems of the LT1 when it first came out. As explained in my previous post, a lot of theories came about and the problem was easily remedied by cleaning, applying an ample amount of sealant and letting sealant cure for a long time (sometimes up to 24 hours depending on climate). It worked. Manifolds galore would not leak. For years and years.
I think your theory has merit for sealant that has been properly applied and has been on the car and been exposed to many different elements over a very long period of time, however for you to come in here and pompously claim you have the definite answer with your amazingly lacking experiment is ludicrous.
I think your theory has merit for sealant that has been properly applied and has been on the car and been exposed to many different elements over a very long period of time, however for you to come in here and pompously claim you have the definite answer with your amazingly lacking experiment is ludicrous.
