# Mysterious oil leak

**URL:** <https://community.cartalk.com/t/mysterious-oil-leak/19808>\
**Category:** Maintenance/Repairs\
**Tags:** ford, oil, leaks, f150\
**Created:** [September 20, 2008, 7:04pm UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808 "2008-09-20T19:04:49Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![390bigblock-power](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/390bigblock-power/32/549_2.png) [@390bigblock-power](https://community.cartalk.com/u/390bigblock-power)\
**Post date:** [September 20, 2008, 7:04pm UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808/1 "2008-09-20T19:04:49Z")

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I have a 1975 Ford F150 with a 390. I’ve noticed that the last few days i have an oil leak that just seems to be getting bigger and bigger. I looked under the truck and I noticed that the whole back of my engine’s oil pan is covered with oil and that is where i think its dripping onto the ground at. When the engines hot it just drips onto the ground like crazy.  
  
 What do you think could be leaking?

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [September 20, 2008, 10:29pm UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808/2 "2008-09-20T22:29:02Z")

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Check if the oil pressure sending unit is leaking. It’s screwed into the side of the engine, next to the oil filter.

Tester

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**Author:** ![pleasedodgevan](https://avatars.discourse-cdn.com/v4/letter/p/51bf81/32.png) [@pleasedodgevan](https://community.cartalk.com/u/pleasedodgevan)\
**Post date:** [September 21, 2008, 4:26am UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808/3 "2008-09-21T04:26:17Z")

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Nice one to check, Tester. We just love plastic parts. Had that problem on a Chevy 350.

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**Author:** ![BustedKnuckles](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bustedknuckles/32/25_2.png) [@BustedKnuckles](https://community.cartalk.com/u/BustedKnuckles)\
**Post date:** [September 21, 2008, 12:37pm UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808/4 "2008-09-21T12:37:50Z")

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If it is the BACK of the engine, near center, like where the engine and transmission mount together, then I suspect rear main seal. And at this rate, it could be almost a total blowout.

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**Author:** ![390bigblock-power](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/390bigblock-power/32/549_2.png) [@390bigblock-power](https://community.cartalk.com/u/390bigblock-power)\
**Post date:** [September 21, 2008, 1:45pm UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808/5 "2008-09-21T13:45:48Z")

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Well I just got done checking over this and it was nice and tight.

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [September 21, 2008, 1:58pm UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808/6 "2008-09-21T13:58:50Z")

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Don’t check for tightness. Start the engine and see if the sending unit is leaking.

Tester

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**Author:** ![390bigblock-power](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/390bigblock-power/32/549_2.png) [@390bigblock-power](https://community.cartalk.com/u/390bigblock-power)\
**Post date:** [September 28, 2008, 6:35pm UTC](https://community.cartalk.com/t/mysterious-oil-leak/19808/7 "2008-09-28T18:35:22Z")

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I checked the sending unit and it did’nt appear to be leaking. The sending unit also isnt real old either.