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Discussion Starter · #1 ·
I have a good running 302 but it leaks a lot of oil ...
looks like it comes from the top rear intake and it flows down on the outside of the Transmission case.....

I suspect someone wiggled the intake when they put it in and the rear gasket came out of place but it's hard to see when it's in the car .......
ANYONE else has this problem?
I guess the only fix is to pull the intake and re gasket it and use lots of RTV gasket maker
OR
is there a way to fix it w/o pulling the intake?
OR
What do you guys do when you put the intake on?
USE lots of RTV silicon?
OR just skip the rear gasket that comes with the kit and ONLY use RTV silicon?
OR use BOTH?
Please advice
thx
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The first thing you can try is using a powerful solvent like acetone or MEK and clean the rear area of the manifold/block. You will probably need to try to spray it with something and keep wiping until you see no oil whatsoever. Then apply a thick bead of silicone across the back of the intake and using a putty knife or something, try to push the sealant up in the cracks of the mating surface and let it dry for a day or two. Its not the right way, but worth a try.
If that fails, you will need to remove the intake and re-gasket. I think the common practice now is to leave the end gaskets off and apply a thick bead of silicone and gently lower the intake in place and torque and let is dry for a day or so and then you will be good to go.
 

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Discussion Starter · #3 ·
Another theory is crankcase pressures is too high and the Breather system not properly installed so the pressure got to go somewhere and I think it pushed the air and the oil out in the rear cause it got to went somewhere ...... Only have one went cap on the one of the valve covers (where you fill the oil) and if the PVC is blocked then there is no where to went?
Anyone second this theory ?
Or am I barking up the wrong tree ....
 

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I have a good running 302 but it leaks a lot of oil ...
looks like it comes from the top rear intake and it flows down on the outside of the Transmission case.....

I suspect someone wiggled the intake when they put it in and the rear gasket came out of place but it's hard to see when it's in the car .......
ANYONE else has this problem?
I guess the only fix is to pull the intake and re gasket it and use lots of RTV gasket maker
OR
is there a way to fix it w/o pulling the intake?
OR
What do you guys do when you put the intake on?
USE lots of RTV silicon?
OR just skip the rear gasket that comes with the kit and ONLY use RTV silicon?
OR use BOTH?
Please advice
thx
To do this correctly, pull the intake manifold. Clean off all the old gasket material on the heads and both ends of the lifter valley. Put down about a 1/4" inch bead of your favorite RTV silicone from end to end where the intake manifold sits at both ends of the lifter valley. Do not use the end gaskets for this..just the RTV. Replace the intake manifold gaskets that go between the intake and the cylinder head. Some folks like to smear a bit of RTV/silicone around the water port cutouts on the gasket before setting them in place. I do, but again, it's just a smear of the stuff all the way around. Get at least two bolts or all thread rod that fit into where the bolts of the intake fit into the head. Cut the head of the bolt off, and grind the remaining area smooth. I just use two, and put them diagonally across from each other, but other folks like to use all four corners. Whichever you do, hand tighten the all thread/bolts in place and use them as a guide to lower the intake into place with worrying about having to move it around to get it all lined up. Torque the manifold in the proper sequence and check it again. After running the engine a few times, check the torque on the bolts some more.

Have fun!
 

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To do this correctly, pull the intake manifold. Clean off all the old gasket material on the heads and both ends of the lifter valley. Put down about a 1/4" inch bead of your favorite RTV silicone from end to end where the intake manifold sits at both ends of the lifter valley. Do not use the end gaskets for this..just the RTV. Replace the intake manifold gaskets that go between the intake and the cylinder head. Some folks like to smear a bit of RTV/silicone around the water port cutouts on the gasket before setting them in place. I do, but again, it's just a smear of the stuff all the way around. Get at least two bolts or all thread rod that fit into where the bolts of the intake fit into the head. Cut the head of the bolt off, and grind the remaining area smooth. I just use two, and put them diagonally across from each other, but other folks like to use all four corners. Whichever you do, hand tighten the all thread/bolts in place and use them as a guide to lower the intake into place with worrying about having to move it around to get it all lined up. Torque the manifold in the proper sequence and check it again. After running the engine a few times, check the torque on the bolts some more.

Have fun!
^^^^^^ This
Pulling the intake is not a difficult job. Just the cleaning part is annoying and be super careful not to get old gasket or RTV into the engine. Clean, clean and clean until you have bare metal. Throw the end gaskets as far away as you can and use a thick bead of RTV (I use grey RTV). I also smear RTV around the water ports on the block side of the gasket. Drain the engine oil since you might got coolant into the oil from removing the intake. It is an afternoon project, not more.
 

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Discussion Starter · #6 ·
^^^^^^ This
Pulling the intake is not a difficult job. Just the cleaning part is annoying and be super careful not to get old gasket or RTV into the engine. Clean, clean and clean until you have bare metal. Throw the end gaskets as far away as you can and use a thick bead of RTV (I use grey RTV). I also smear RTV around the water ports on the block side of the gasket. Drain the engine oil since you might got coolant into the oil from removing the intake. It is an afternoon project, not more.
Got the Fel PRO gasket set today .... looks like the front and rear cork gasket is replaced by a blue plastic one
Still not sure if I will use it with RTV or throw it away ....
hmmm
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To do this correctly, pull the intake manifold. Clean off all the old gasket material on the heads and both ends of the lifter valley. Put down about a 1/4" inch bead of your favorite RTV silicone from end to end where the intake manifold sits at both ends of the lifter valley. Do not use the end gaskets for this..just the RTV. Replace the intake manifold gaskets that go between the intake and the cylinder head. Some folks like to smear a bit of RTV/silicone around the water port cutouts on the gasket before setting them in place. I do, but again, it's just a smear of the stuff all the way around. Get at least two bolts or all thread rod that fit into where the bolts of the intake fit into the head. Cut the head of the bolt off, and grind the remaining area smooth. I just use two, and put them diagonally across from each other, but other folks like to use all four corners. Whichever you do, hand tighten the all thread/bolts in place and use them as a guide to lower the intake into place with worrying about having to move it around to get it all lined up. Torque the manifold in the proper sequence and check it again. After running the engine a few times, check the torque on the bolts some more.

Have fun!
I would also suggest you drain a gallon or so of coolant before removing the intake manifold to ensure that there is no coolant in the manifold that could go into the lifter galley and into the oil pan when you pull the manifold off.
 

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Discussion Starter · #8 ·
Also noticed my intake studs was not really torqued down ....
I went for 10 pound torqued torqued and I could turn them all
and as I understand they should be to 20 foot pound ... right
So I might give it another torque tonight and drive it for a while
to see if any leaks slowed down ...

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I would also suggest you drain a gallon or so of coolant before removing the intake manifold to ensure that there is no coolant in the manifold that could go into the lifter galley and into the oil pan when you pull the manifold off.
I pull off the upper radiator hose from the manifold.
 

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Got the Fel PRO gasket set today .... looks like the front and rear cork gasket is replaced by a blue plastic one
Still not sure if I will use it with RTV or throw it away ....
hmmm
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Don’t use the valley gaskets no matter the material. Use rtv. I have been doing it this way over 20 years without a leak. I also put a little around the water ports.
 

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I set all the gaskets place. I rtv the downside of the valley gaskets and let it dry over night. The next day will then rtv around the water jacket and the top of the valley gaskets....never had an issue.

I will always conduct a blind feel test after torqing as a sanity check.

I've also had some valley gaskets with an adhesive side and those work well too...has to be super clean .
 

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Using 4 studs (or 4 long bolts that you cut the heads off of) in positions 1, 2, 3, 4 in the above diagram will help ensure that the new port gaskets and the manifold are installed straight on the valley.

My preference is to replace the end seals with "Right Stuff" rtv. I've never had a leak when this stuff is used. If you use Right Stuff and the manifold needs to be removed in the future, expect to use a razor blade to slice the dried RTV before trying to separate the manifold from the block.
 

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Just to confuse the issue more. I like to place the manifold onto the block without any gaskets so I can see the size of the gap at the front and the back of the manifold. If I can easily slide the rail gaskets through the gap, I will rtv them to the block and let it sit most of the day so that they are securely attached before proceeding with the install. If they are tight or will not slide through I do not use them and apply a good bead of rtv instead.
 

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Never used anything but the cork gaskets. Permatex Aviation Form-a-Gasket and allow it to set up, same around the water ports, cut down 5" bolts with the heads whacked off at the 4 corners as alignment guides.
 
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