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6/24/2023 5:12 PM  #1


unknown oil leak

On my 65 289 just rebuilt 3K ago i had a rear corn of the valve cover leak that would not  go away. This last attempt i sealed the new rubber gaskets to the covers and let dry then added a very fine film of RTV to the gasket and installed. Now less than 100 miles later I still am finding some oil at the bottom of the bell hosing. not a lot but enough that it will blow onto the tranny pan. Could this be leftover from the bad leak or is there a secret hole somewhere. It seams to now be dry at the heads. Infact I cant find any trace just at the very bottom after a short drive.. I removed the small inspection cover on the C4 and it is dry inside. Seams to come down from around the starter and settle in at the bottom of the bellhousing
Any ideas????


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
 

6/24/2023 5:25 PM  #2


Re: unknown oil leak

Sounds like your starter is leaking oil !!!!
J/K
Mustangsteve recommends clean it really well and dry it.
Then......spray the area with jock itch powder !!!!        NOT/Kidd'in
The idea is  IF....there is a leak the sprayed powder will help locate the leak, by leaving a trail thru the jock itch powder.
Really.......any kinda dry spray powder will work.

Did you really crank down on the VC bolts when installing? (mighta crushed the gasket??!)

I have chunked the gaskets altogether and spread a THICK bead of RTV  It didn't leak butt.........
MAN was it hard to get the VC off a few years later !!!

This time I used just rubber gaskets and didn't crank 'em down too tight.

6sally6


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

6/24/2023 6:21 PM  #3


Re: unknown oil leak

Go to car wash. Clean thoroughly. Let dry. Dpray eith WalMart jock itch spray.
Drive five miles. You leak will become visible.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

6/24/2023 8:59 PM  #4


Re: unknown oil leak

car and motor are clean. I will try the powder. Does it come in a spray can? Maybe it will help with the lumpy cam too, cant hurt


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/25/2023 3:12 PM  #5


Re: unknown oil leak



OK this is in 5 miles, everything up top is dry, So is this rear main seal? In 5 more miles I will have some at the bottom starting to drip I think


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/25/2023 3:30 PM  #6


Re: unknown oil leak

Well after looking on you tube I see it should  not be to hard to do, especially being a fresh motor. 


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/25/2023 3:53 PM  #7


Re: unknown oil leak

Check the back of the manifold where it meets the lifter valley. 


65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.
 

6/25/2023 4:13 PM  #8


Re: unknown oil leak

Two piece rear main seal just requires you to pull the oil pan and #5 main cap.  Be sure to remove the little nail in the cap if it still exists. Clock the seal 3/8” off the end of the cap and block and be sure to get it facing the right way.

When threading the new seal up into the block groove, press the seal hard up against the crank as you push it in with a little oil on it. Failure to press it against the crank journal assures you will have a hard time pushing it in, plus material will get sheared off as it goes in.  Once I learned to compress the seal against the crank, I have been able to slide them in place entirely by hand pressure.

Do NOT put RTV or anything else on the ends of the seal where the upper and lower seal mate up.

A small amount of RTV on the outer corners of the main cap will keep oil from leaking through the parting line.

Be sure seal is oiled when installed.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

6/25/2023 4:30 PM  #9


Re: unknown oil leak

Bob, I powdered the whole rear of the motor. It was always dry up around the intake, but I did have the PS valve cover leaking but this makes total sense  as I remember putting that seal in flush with the block. Back of motor is dry


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/25/2023 4:33 PM  #10


Re: unknown oil leak

Thanks for the powder idea, now my car has no itch.


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/25/2023 5:07 PM  #11


Re: unknown oil leak

Possibly a leak at the oil pan gasket in the corner where it goes over the crank.


"Those telephone poles were like a picket fence"
 

6/25/2023 5:52 PM  #12


Re: unknown oil leak

I am starting to agree with 50vert. I pulled the little inspection cover and it is all dry inside as you mite be able to tell from these pictures taken with scope. It seams to me if the seal was leaking as much as I can get oil there would be some/lots inside between the flex plate and the trans cover. I dont know what the brown runs are from but they are hard and on the inside surface of the spacer that bolts to the block that should be wet from the seal leaking  I think


Last edited by Cab4word67 (6/25/2023 6:05 PM)


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/25/2023 6:16 PM  #13


Re: unknown oil leak

I knew about sealing the 4 corners with RTV when using the 4 piece cork gaskets. Thought it wasn't needed when using a 1 piece gasket .... not true.


"Those telephone poles were like a picket fence"
 

6/25/2023 6:32 PM  #14


Re: unknown oil leak

This was a cork set. It came with the rebuild. We will replace with one piece and still dab the cornes like I did years ago.


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/25/2023 8:54 PM  #15


Re: unknown oil leak

From my experience with those one piece FelPro blue pan gaskets, you have a 50-50 chance it will leak at the radiused ends.  If I use a gasket at all, I use those and cut the radiused ends off and use RTV for the ends.  I have had to pull the pan on two different engines, luckily discovered before putting them in the car, where the end seals did not seal against the pan. The RTV IS BULLETPROOF.

On the 5.0 I just completed, I used RTV Ultra Grey without a gasket.  Since there is no extra gasket thickness on the sides, it takes alot less RTV on the ends to do the job. I have never had a leak on an oil pan done that way.

Sal said his was hard to disassemble, but if you drive a tapered wedge maybe 1/8” thick into one corner, then go drink one of your favorite beverages, when you come back the entire pan will be disconnected.  It just takes a little force for the RTV to start separating.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

6/25/2023 9:43 PM  #16


Re: unknown oil leak

Good advice MS. I know right where you are coming from, something to ponder


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/26/2023 11:09 AM  #17


Re: unknown oil leak

It's too late now butt.......
My advice on oil pan gaskets still stand !
(What advice you my axe?  First, take gasket and tightly roll it up on itself to form a firm ball of rubber.... next use TWO rubber bands OR a medium zip tie and secure around the gasket ball.... next while holding gasket ball in right hand lift lid on your shop trash can with your left hand....next see if the gasket ball will bounce as it is thrown into trash can. If not...leave it!
  If it DOES bounce...consider a career change as a pitcher in professional baseball!)
6sally6

PS I prefer blue RTV as a gasket substitute because its purdy-er  (dat a word?) and it matches the Ford blue engine paint.


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

6/27/2023 11:26 AM  #18


Re: unknown oil leak

Yes Sal that is a word, but my block is OEM black so it would not match. But then ether dose the blue one piece. 


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

6/27/2023 3:14 PM  #19


Re: unknown oil leak

I'm using a black 1 piece from Ford Motorsports.


"Those telephone poles were like a picket fence"
 

6/27/2023 4:06 PM  #20


Re: unknown oil leak

PS: the brown runs look like the old cork gasket adhesive we useta use back in the day.


"Those telephone poles were like a picket fence"
 

6/27/2023 10:31 PM  #21


Re: unknown oil leak

Kinda werid they are on the inside of the trans spacer, and I dont remimber them when I installed tranny, or when I installed the engine last spring. but they are hard. I will get the new gasket installed this weekend because it will be to hot to work in the yard. 


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

7/02/2023 11:33 AM  #22


Re: unknown oil leak

Well I will admit when Iam wrong but I dont like too. While powdering my pan/tranny and rechecking bolts I went around the bolts one more time, I dont like to make these all to tight and felt tey were fine but Im guessing not.  And the leak has stopped, or I have run out of oil. I now have a new rear seal and pan gasket set in the cuboard and will leave the cork one on for now. 


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
     Thread Starter
 

7/02/2023 1:46 PM  #23


Re: unknown oil leak

Cab4word67 wrote:

Well I will admit when Iam wrong but I dont like too. While powdering my pan/tranny and rechecking bolts I went around the bolts one more time, I dont like to make these all to tight and felt tey were fine but Im guessing not.  And the leak has stopped, or I have run out of oil. I now have a new rear seal and pan gasket set in the cuboard and will leave the cork one on for now. 

Awwwwwwwwwwwwww.......the joys of shade-tree canic'in !!

Glad ye got it.
(how hot is "too hot to work out side"..... in Organ?)
 
6sal5


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

7/03/2023 6:39 AM  #24


Re: unknown oil leak

Yep, I changed the rear main seal (one-piece) thinking it was my problem, only to find a small oil leak on the back of the manifold.  Caulk it up to ‘experience’! 


65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.
 

7/03/2023 12:10 PM  #25


Re: unknown oil leak

6sally6 wrote:

Cab4word67 wrote:

Well I will admit when Iam wrong but I dont like too. While powdering my pan/tranny and rechecking bolts I went around the bolts one more time, I dont like to make these all to tight and felt tey were fine but Im guessing not.  And the leak has stopped, or I have run out of oil. I now have a new rear seal and pan gasket set in the cuboard and will leave the cork one on for now. 

Awwwwwwwwwwwwww.......the joys of shade-tree canic'in !!

Glad ye got it.
(how hot is "too hot to work out side"..... in Organ?)
 
6sal5

It's pronounced Orygun.....not Ore-a-gone like they say back East. Up here in the Pacific Northwest we aren't lucky enough to experience the 100+ degree 98% humidity, hurricanes, tornadoes, baseball sized hail, 28" of rain in 24 hours, etc type of weather all y'all get to experience down south and in the southeast. So once the temperature hits a balmy 85+ we like to retire under our shady Douglas firs to await the cooler temperatures.... :-)
 

Last edited by Ron68 (7/03/2023 12:12 PM)


68 coupe - 351W, 4R70W, 9" 3.25 -- 65 convertible - 289 4v, C4, 8" 3.00
 

Board footera


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