Chevy 305 sprung a leak. There's a lot oil coming out from the oil pressure sender.

[rs2k]

Any idea on how to fix it? The leak is so bad that you can hear the hole whistle when a vacuum is applied to the PCV system. The leak is going right past the threads of the oil pressure sender. I tried to use Teflon tape and an o-ring, but that only slowed the leak down. This engine always had a bit of a leak there, but now it's getting really bad and messy! It's loosing a quart per hour.

 

[Bt Doctur]

Re: Chevy 305 sprung a leak. There's a lot oil coming out from the oil pressure sende

the sender usually threads into a extention,something cracked but i dont understand the "when vac is applied:" this has nothing to do with oil pressure or senders

 

[rs2k]

Re: Chevy 305 sprung a leak. There's a lot oil coming out from the oil pressure sende

I have a vacuum setup on the PCV system. Both PCV holes in the valve covers go to a Tee which then go to the intake manifold. When there is vacuum applied to this PCV system (the engine is idling) there is a loud whistle from the oil pressure sender.

The oil pressure sender is mounted directly to threaded hole in the block which is just aft of the intake manifold, just port of the distributor, and above the oil filter and oil pump.

I did not see a crack when I cleaned the hole, nor did I see a crack when I looked at the oil pressure sender. This is what is confusing me. You can plainly see oil coming out from around the threads and three wraps of Teflon tape did not fix the problem. I know for sure I can wrap the tape around more because of how easy the sender went in with three wraps. I'm just not sure about putting wraps of Teflon tape in there to stop a leak.

 

[Bt Doctur]

Re: Chevy 305 sprung a leak. There's a lot oil coming out from the oil pressure sende

like i said the pvc system , (plumbed wrong anyway) has nothing to do with senders.sucks from 1, vents in from the other, not both
The sender threads into the block, a crack there means the block cracked
try removing the sender and installing a plug , see if it still leaks,
plug off the pvc hoses and recheck.
plumbed that way with the manifold vac applied the whistle could be a intake manifold leak , gaskets are not used anymore just a thick bead of silicone on the front and rear

 

[dan t.]

Re: Chevy 305 sprung a leak. There's a lot oil coming out from the oil pressure sende

sounds to me like you have sucked the manifold to block gasket in to the motor ,the oil could be coming out there. a pcv must have a fresh air inlet, this is the whole idea, to pull fresh air thru the motor.I have the normal marine breather which runs to the spark arrestor on one side and the pcv valve on the other ,works good