This is my vote.
On the intake manifold
Thread Starter
Cruising
Joined: Apr 2006
Posts: 12
Likes: 0
From: Iring NY
On the intake manifold
ANy idea where oil would come from that accumulates on the passenger side manifold between the two pipes coming down? It doesn't appear to be coming from the valve cover.
http://i134.photobucket.com/albums/q...etteengine.jpg
Thanks! Looking forward to spring!
http://i134.photobucket.com/albums/q...etteengine.jpg
Thanks! Looking forward to spring!
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
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It could be coming from the intake manifold itself. The engines are fairly leak prone and the manifold is a common oil leak location.
Le Mans Master
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From: Jenison MI
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St. Jude Donor '06
Le Mans Master
Joined: Sep 2006
Posts: 6,050
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From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
oil leak
I have dealt with this problem for years. The oil wicks up the center manifold hold down bolts, and deposits itself in the little valley at the sides of the manifold.
The other 4 bolts on each side are controlling the water passages. The water tends to have more resistance to wicking, or creep.
The answer seems to be adding silicone to the threads. But once that's done, you can't retighten them, for fear of fracturing the silicone sealing properties.
You can't keep removing and reinstalling those bolts with silicone on them because eventually you will push bits of cured silicone through the holes,and they lay in the lifter valley and eventually find their way to the pan, and into the oil pump pick-up screen.
Sometimes, i have to put copper (read soft) washers on the bolts and keep checking the torque on them as time progresses.
With each heating and cooling cycle, the aluminum, cast iron, and steel work together on the gasket pinch to flatten out the gasket every day that the engine runs, and shuts off and is allowed to cool.
In that the manifold and heads are aluminum, the block is cast iron, and the bolts are steel, the washers copper, the four metals tend to expand at different rates, and installing lock washers or silicone, or loc-tight only tends to aggravate the problem.
You can change to an external wrenching bolt (hex head) on those bolts,to make it easier to tighten,
BUT....... remember the middle 2 bolts on each side are shorter than the other 4 bolts because under the R/H forward center bolt is the pushrod, and under the L/H rearward center bolt is the other pushrod.
Lengthening those bolts might allow you to rub the pushrods on the bolts or bend them enough to make them crack and break, and send tiny pieces of metal through the oil to the oil pan where it may or may not be caught in the filter, depending on where the bypass valve is when the oil is the thickest.
So the best thing is to remove the bolts, squirt black, non amonia smelling silicone on the threads, and reinsert them.
Why non amonia smelling silicone? Because the types that smell like amonia attack aluminum.
The other 4 bolts on each side are controlling the water passages. The water tends to have more resistance to wicking, or creep.
The answer seems to be adding silicone to the threads. But once that's done, you can't retighten them, for fear of fracturing the silicone sealing properties.
You can't keep removing and reinstalling those bolts with silicone on them because eventually you will push bits of cured silicone through the holes,and they lay in the lifter valley and eventually find their way to the pan, and into the oil pump pick-up screen.
Sometimes, i have to put copper (read soft) washers on the bolts and keep checking the torque on them as time progresses.
With each heating and cooling cycle, the aluminum, cast iron, and steel work together on the gasket pinch to flatten out the gasket every day that the engine runs, and shuts off and is allowed to cool.
In that the manifold and heads are aluminum, the block is cast iron, and the bolts are steel, the washers copper, the four metals tend to expand at different rates, and installing lock washers or silicone, or loc-tight only tends to aggravate the problem.
You can change to an external wrenching bolt (hex head) on those bolts,to make it easier to tighten,
BUT....... remember the middle 2 bolts on each side are shorter than the other 4 bolts because under the R/H forward center bolt is the pushrod, and under the L/H rearward center bolt is the other pushrod.
Lengthening those bolts might allow you to rub the pushrods on the bolts or bend them enough to make them crack and break, and send tiny pieces of metal through the oil to the oil pan where it may or may not be caught in the filter, depending on where the bypass valve is when the oil is the thickest.
So the best thing is to remove the bolts, squirt black, non amonia smelling silicone on the threads, and reinsert them.
Why non amonia smelling silicone? Because the types that smell like amonia attack aluminum.
Last edited by coupeguy2001; Jan 12, 2007 at 12:50 PM.
Instructor
Joined: Dec 2006
Posts: 213
Likes: 0
From: sparta michigan
I have dealt with this problem for years. The oil wicks up the center manifold hold down bolts, and deposits itself in the little valley at the sides of the manifold.
The other 4 bolts on each side are controlling the water passages. The water tends to have more resistance to wicking, or creep.
The answer seems to be adding silicone to the threads. But once that's done, you can't retighten them, for fear of fracturing the silicone sealing properties.
You can't keep removing and reinstalling those bolts with silicone on them because eventually you will push bits of cured silicone through the holes,and they lay in the lifter valley and eventually find their way to the pan, and into the oil pump pick-up screen.
Sometimes, i have to put copper (read soft) washers on the bolts and keep checking the torque on them as time progresses.
With each heating and cooling cycle, the aluminum, cast iron, and steel work together on the gasket pinch to flatten out the gasket every day that the engine runs, and shuts off and is allowed to cool.
In that the manifold and heads are aluminum, the block is cast iron, and the bolts are steel, the washers copper, the four metals tend to expand at different rates, and installing lock washers or silicone, or loc-tight only tends to aggravate the problem.
You can change to an external wrenching bolt (hex head) on those bolts,to make it easier to tighten,
BUT....... remember the middle 2 bolts on each side are shorter than the other 4 bolts because under the R/H forward center bolt is the pushrod, and under the L/H rearward center bolt is the other pushrod.
Lengthening those bolts might allow you to rub the pushrods on the bolts or bend them enough to make them crack and break, and send tiny pieces of metal through the oil to the oil pan where it may or may not be caught in the filter, depending on where the bypass valve is when the oil is the thickest.
So the best thing is to remove the bolts, squirt black, non amonia smelling silicone on the threads, and reinsert them.
Why non amonia smelling silicone? Because the types that smell like amonia attack aluminum.
The other 4 bolts on each side are controlling the water passages. The water tends to have more resistance to wicking, or creep.
The answer seems to be adding silicone to the threads. But once that's done, you can't retighten them, for fear of fracturing the silicone sealing properties.
You can't keep removing and reinstalling those bolts with silicone on them because eventually you will push bits of cured silicone through the holes,and they lay in the lifter valley and eventually find their way to the pan, and into the oil pump pick-up screen.
Sometimes, i have to put copper (read soft) washers on the bolts and keep checking the torque on them as time progresses.
With each heating and cooling cycle, the aluminum, cast iron, and steel work together on the gasket pinch to flatten out the gasket every day that the engine runs, and shuts off and is allowed to cool.
In that the manifold and heads are aluminum, the block is cast iron, and the bolts are steel, the washers copper, the four metals tend to expand at different rates, and installing lock washers or silicone, or loc-tight only tends to aggravate the problem.
You can change to an external wrenching bolt (hex head) on those bolts,to make it easier to tighten,
BUT....... remember the middle 2 bolts on each side are shorter than the other 4 bolts because under the R/H forward center bolt is the pushrod, and under the L/H rearward center bolt is the other pushrod.
Lengthening those bolts might allow you to rub the pushrods on the bolts or bend them enough to make them crack and break, and send tiny pieces of metal through the oil to the oil pan where it may or may not be caught in the filter, depending on where the bypass valve is when the oil is the thickest.
So the best thing is to remove the bolts, squirt black, non amonia smelling silicone on the threads, and reinsert them.
Why non amonia smelling silicone? Because the types that smell like amonia attack aluminum.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Clean the area where the oil leak is...with degreaser. Then run the car a little and see if you can tell where it's coming from. The intake manifold can be taken off and a new gasket installed in a complete day. If so, make sure you buy the correct gaskets and only use RTV on the front and rear. 40 torx for the plenum and runner bolts and 45 torx for the intake manifold bolts.
Remember preparation goes a long way when doing things like this.
Remember preparation goes a long way when doing things like this.
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
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Cruise-In VII Veteran
Cruise-In VIII Veteran
Clean the area where the oil leak is...with degreaser. Then run the car a little and see if you can tell where it's coming from. The intake manifold can be taken off and a new gasket installed in a complete day. If so, make sure you buy the correct gaskets and only use RTV on the front and rear. 40 torx for the plenum and runner bolts and 45 torx for the intake manifold bolts.
Remember preparation goes a long way when doing things like this.
Remember preparation goes a long way when doing things like this.
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