Author Topic: Oil leak near top back of engine.  (Read 4578 times)

Offline 74 challenge

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Oil leak near top back of engine.
« on: July 10, 2013 - 08:13:01 AM »
I am having an oil leak that is re-occuring and I am just not sure why.

This spring/ early summer I replaced the intake manifold gaskets, the distributor and valve cover gaskets to chase this oil leak I cannot seem to pint point.

After any car ride once I park the car off the bell housing drips 25-50 ml of motor oil. It is not from inside the bell housing as it is dry. It comes from the back of the engine flows down the back of the engine onto the trans bell housing and onto the ground.

When I replaced the gaskets I made sure to use a good bead of RTV on the front and back of the engine and it looked like it sealed great. The distributor was giving a little oil off but I added some RTV to the O ring when I put it back in for the second time to get rid of that oil leak. I have an oil pressure guage coming from that area aswell but it is dry and tight.

What am I missing? is there something back there that can leak a good amount of oil? or did my intake manifold not seal properly?

Aditional info:

318, A904, Edelbrock performer intake, stock iron heads, Summit racing distributor, oil pressure is normal and the guage reads normally no drops in oil pressure, distinct burning smell when driving.
1-8-4-3-6-5-7-2




Offline 72cudamaan

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Re: Oil leak near top back of engine.
« Reply #1 on: July 10, 2013 - 08:38:48 AM »
First, get that rtv off of the o-ring. It will leak for sure. Are you sure the leak isn't still from
the V/covers? Common difficult to seal area. Clean off the back of the engine with brake kleen and
run the engine. You could probably use a mirror to see the back of the engine and watch for the leak.
If I cant fix it, it's broke
 
Andy  (phukker whither)

Offline 74 challenge

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Re: Oil leak near top back of engine.
« Reply #2 on: July 10, 2013 - 09:11:03 AM »
First, get that rtv off of the o-ring. It will leak for sure. Are you sure the leak isn't still from
the V/covers? Common difficult to seal area. Clean off the back of the engine with brake kleen and
run the engine. You could probably use a mirror to see the back of the engine and watch for the leak.

IT leaked without the RTV too. Why would it leak more with the RTV?

I replaced the valve covers less than 2 weeks ago and when I ran a kleenex around the perimieter of them last night there is zero oil on it. The engine was too hot to be able to get in there around the distributor back of heads area and get a good look.

I was very confident in the seal of the intake manifold when I re-assembled the engine but the more I look at it the less confident i am becoming. I have put on what feel like 1000 intake manifolds before.
1-8-4-3-6-5-7-2

Offline Bullitt-

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Re: Oil leak near top back of engine.
« Reply #3 on: July 10, 2013 - 09:34:39 AM »
Had the same issue myself & have read many times when installing the intake manifold gasket to put plenty of RTV in the corners..
Also check that it's not your oil pressure sending unit.
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
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Offline Super Blue 72

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Re: Oil leak near top back of engine.
« Reply #4 on: July 10, 2013 - 09:47:32 AM »
Like the guys have said, intake and oil pressure sending unit is where I would check first. The end gaskets are easy to squeeze out when putting the manifold is being placed back. Clean everything and let it run.

Is there a freeze plug on the back of the engine block that can leak?  Can't remember if that's a Mopar issue or a Honda problem. Gettin old. Also the rear main seal could be leaking.

Just retread your first post and it appears its leaking from the top and then down the back of the engine. Doubt it's the rear main or freeze plugs..probably intake or sender unit.
1972 Dodge Challenger Rallye 340, AT, Code TB3=Super Blue, SBD=8/17/1971.  Yes, a Rallye without the fender louvers from the factory because of the body side molding option.

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Offline 74 challenge

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Re: Oil leak near top back of engine.
« Reply #5 on: July 10, 2013 - 11:54:18 AM »
Like the guys have said, intake and oil pressure sending unit is where I would check first. The end gaskets are easy to squeeze out when putting the manifold is being placed back. Clean everything and let it run.

Is there a freeze plug on the back of the engine block that can leak?  Can't remember if that's a Mopar issue or a Honda problem. Gettin old. Also the rear main seal could be leaking.

Just retread your first post and it appears its leaking from the top and then down the back of the engine. Doubt it's the rear main or freeze plugs..probably intake or sender unit.

Yeah I put plenty of RTV on especially extra in the corners. All edelbrock intakes are put on with just RTV in the ends and I even let it cure before putting oil back in the car.

Where is the oil pressure sending unit? I Have not looked at this thing ever so it could be the cause. There is way more oil going down the passenger side of the engine over the drivers side.
1-8-4-3-6-5-7-2

Offline Bullitt-

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Re: Oil leak near top back of engine.
« Reply #6 on: July 10, 2013 - 03:51:12 PM »
Oil sending unit is beside the distributor on the passenger side
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
Screwed by Photobucket!

Offline 74 challenge

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Re: Oil leak near top back of engine.
« Reply #7 on: July 11, 2013 - 07:40:48 AM »
Oil sending unit is beside the distributor on the passenger side

Took at look and used a part from the internet I definately do not have this peice. I have a mechanical oil pressure guage that runs a small pipe from that area on the block to inside the car. It is tight and dry.

I think this is a poorly sealed intake manifold.

TIme to get a mirror in there and take a look.
1-8-4-3-6-5-7-2

Offline Chryco Psycho

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Re: Oil leak near top back of engine.
« Reply #8 on: July 11, 2013 - 01:07:21 PM »
Are you running a PCV on the engine ?
too much internal pressure could be forcing oil out .
I had the sam issue with a 340 , the fitting for the oil line was split & would leak oil at higher rpm but never at idle

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Offline 74 challenge

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Re: Oil leak near top back of engine.
« Reply #9 on: July 11, 2013 - 01:30:20 PM »
Are you running a PCV on the engine ?
too much internal pressure could be forcing oil out .
I had the sam issue with a 340 , the fitting for the oil line was split & would leak oil at higher rpm but never at idle

On the drivers side I have a PCV going to the carb and on the passenger side I have one of those chrome MOPAR breathers. I do from time to time get a drip of oil coming from the chrome breather. The PVC is new and works well when I suck on the tube.
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Offline Chryco Psycho

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Re: Oil leak near top back of engine.
« Reply #10 on: July 11, 2013 - 01:31:44 PM »
 :2thumbs:

Challenger - You`ll wish You Hadn`t