Not sure where oil is leaking

[78 Square]

I just noticed a motor oil leak I have dripping right in front of the tranny pan on both sides. the truck doesn't have a flexplate cover on it so I'm not sure if it's running down the block from the black of my valve covers, where I can't see, or maybe I picked up the wrong oil filter by mistake. It only leaks when the truck is running. Just curious if any of you guys have any similar occurrences or any suggestions. Thanks

 

[78 Square]

Or maybe oil pump? I don't know why it's dripping on both sides though

 

[flyboy1100]

Or maybe oil pump? I don't know why it's dripping on both sides though

rear intake manifold, then dripping/running down both sides? i think that is what mine is doing.

 

[Boone83K10]

Mine did this. Its the intake manifold. Take it off and put new gaskets on the sides and then use RTV on the front and rear walls do not use the rubber seals

 

[78 Square]

rear intake manifold, then dripping/running down both sides? i think that is what mine is doing.

Hell, I didn't even think of that lol. My first thought was it's probably some major oil seal on the motor, knowing my luck lol

 

[78 Square]

Mine did this. Its the intake manifold. Take it off and put new gaskets on the sides and then use RTV on the front and rear walls do not use the rubber seals

I'm glad it isn't something real major. Shouldn't be too bad to change. Thanks a lot!

 

[Boone83K10]

Also, make sure that you put a little bit of RTV around the coolant passages. Just smear it on there real thin.

 

[78 Square]

Also, make sure that you put a little bit of RTV around the coolant passages. Just smear it on there real thin.

Alrighty will do, thanks for the advice

 

[smoothandlow84]

Check your oil pressure sending unit as well. They are notorious for leaking when the motor is running.

 

[83kid]

I used the rubber seals when mine was doing this on the front and back, just put big globs of rtv in the corners and a little bead on either side of the seals in the front and back

 

[HotRodPC]

Both of my suggestions have been suggested. Intake gasket or the oil pressure sender switch.

 

[chengny]

1. Valve cover gaskets

2. Distributor shaft bore gasket

3. Either of the oil sensors

and the worst case:

4. Rear main seal


I would save the intake manifold gasket replacement until all the above have been eliminated. There is no pressurized oil in the lifter valley - and only a small trickle back down the pushrods. Unless the intake manifold has been recently disturbed, it is not generally a common location for oil leakage.


I would take a close look at the valve covers - if the gaskets are cork they get hard and lose their resiliency after a few years. The oil that comes out of the tops of the push rods flows to the back of the heads due to the mounting angle of the engine. It is supposed to drain down into the sump but it will rise above the level of the gaskets at the outer back corners. Just try re-torquing the bolts first.

 

[78 Square]

Well it definitely looks like the oil pressure switch. I'm almost 100% sure it isn't the valve cover gasket and it doesn't really look like the intake manifold from what I can see. I guess All I can do Is fix that and see if it still does it. But would that really make it leak that much just from giving it moderate throttle for 20 seconds or so?

 

[78 Square]

My oil pressure gauge still works. so I was thinking I'll take it out and put a little RTV on the threads as long as they look alright

 

[smoothandlow84]

Your oil pressure while at idle can be between 20 and 35 psi...with a leaky pressure switch, it will spew oil out quite fast. My first square was a 1978 and it leaked like crazy....and drove me nuts til I found it.