No Way Is This The Source Of My Oil Leak? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Gregski** · 01-02-2015, 10:42 PM

this can't be where my oil is leaking from can it, that piece above the starter should be a solid chunk of metal, no? what are those two bolt holes for, application for a different car?

Just call me Sean · 01-02-2015, 11:24 PM

No oil goes through there.

86c20 · 01-02-2015, 11:46 PM

only way i see oil there is from back or intake or vavle cover down to the bell and then out the holes. only way i see. and that is a stretch

andrewmp6 · 01-03-2015, 03:58 AM

See if the flexplate is coated in oil,If it is its your rear main seal.But like others have side its probably from up higher and dripping down.

homemade87 · 01-03-2015, 07:48 AM

From the looks of it thru your starter hole it looks pretty black and wet . If I was a guessing person I would say there is a rear main seal leak . If you had oil moving around on the back of the block it could get between the trans and engine block mating surfaces . It looks like its coming from the locating pin for the trans . That is a thru hole in the block with a pin in it . It could be possible for oil to make its way past that pin from the back of the block if oil gets trapped between the 2 mating surfaces . It looks to be a very minor seep . Not the source of a major oil leak . Oil is originating from some where else . What you are seeing is collateral damage .

**hatzie** · 01-03-2015, 10:47 AM

That's coming from under the bellhousing. It's a little odd that the bellhousing and inspection cover look wet but the flex plate looks dry.
The oil pressure senders are on the other side of the block and there's no oil on the outside anyway.
There are no ribs for an oil gallery or cam plug leak to run down there without wetting down the flex plate and a rear main leak should soak it as well.

Did you have a bad rear main leak that was corrected? It could be oil caught in the locator dowel hole from a prior leak or running down the inside of the bellhousing seeping out.

**Gregski** · 02-09-2015, 11:25 PM

guys with a three day weekend coming up I want to tackle this job, but I have no idea where to start, do I pull the tranny off and remove the bell housing and inspect that area, or do I drop the oil pan (again) and that's where the rear main oil seal lives

Chaplain · 02-10-2015, 04:35 AM

I have no idea where the source of your oil is but just from watching your other post, I don't think you're going stop until you have the engine and trans out. I'm just saying.

Besides that's what I'm doing.

homemade87 · 02-10-2015, 08:07 AM

From the looks of the inside of the bell housing my guess would be the rear main seal . If you have a 2-piece rear main seal I would drop the oil pan and replace it. I see a blue edge on the oil pan . Is that one of felpro one piece gaskets . If so you should be able to reuse it . If you have a one piece seal this is not an option . You will have to drop the trans.

Just take a good look at the top rear of the engine before you do this . Make sure there is no oil coming from a oil sending unit, valve covers or intake seal . My guess there is not . You would see more evidence of oil on the outside of the bell housing . Hope all goes well .

01-02-2015, 10:42 PM	#1
Gregski Post Whore Join Date: Aug 2014 Location: Sacramento, CA Posts: 10,820	No Way Is This The Source Of My Oil Leak? this can't be where my oil is leaking from can it, that piece above the starter should be a solid chunk of metal, no? what are those two bolt holes for, application for a different car? Attached Images

01-02-2015, 11:46 PM	#3
86c20 Registered User Join Date: Mar 2012 Location: edgartown mass Posts: 852	Re: No Way Is This The Source Of My Oil Leak? only way i see oil there is from back or intake or vavle cover down to the bell and then out the holes. only way i see. and that is a stretch __________________ 1986 c20 "the hillbilly" 350 sm465 3.42gears 21mpg at 70mph 1985 k30 "the ice cream truck from hell" no rust az truck 197-8??? c30 "ramp truck" 454 1978 monte carlo 350 350th with 2.73 gears. no rust. sc car

01-03-2015, 03:58 AM	#4
andrewmp6 Registered User Join Date: Jan 2009 Location: Louisville,Ky Posts: 5,811	Re: No Way Is This The Source Of My Oil Leak? See if the flexplate is coated in oil,If it is its your rear main seal.But like others have side its probably from up higher and dripping down.

01-03-2015, 07:48 AM	#5
homemade87 Registered User Join Date: Apr 2010 Location: Guntersville Alabama Posts: 1,073	Re: No Way Is This The Source Of My Oil Leak? From the looks of it thru your starter hole it looks pretty black and wet . If I was a guessing person I would say there is a rear main seal leak . If you had oil moving around on the back of the block it could get between the trans and engine block mating surfaces . It looks like its coming from the locating pin for the trans . That is a thru hole in the block with a pin in it . It could be possible for oil to make its way past that pin from the back of the block if oil gets trapped between the 2 mating surfaces . It looks to be a very minor seep . Not the source of a major oil leak . Oil is originating from some where else . What you are seeing is collateral damage .

01-03-2015, 10:47 AM	#6
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,933	Re: No Way Is This The Source Of My Oil Leak? That's coming from under the bellhousing. It's a little odd that the bellhousing and inspection cover look wet but the flex plate looks dry. The oil pressure senders are on the other side of the block and there's no oil on the outside anyway. There are no ribs for an oil gallery or cam plug leak to run down there without wetting down the flex plate and a rear main leak should soak it as well. Did you have a bad rear main leak that was corrected? It could be oil caught in the locator dowel hole from a prior leak or running down the inside of the bellhousing seeping out. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

02-09-2015, 11:25 PM	#7
Gregski Post Whore Join Date: Aug 2014 Location: Sacramento, CA Posts: 10,820	Re: No Way Is This The Source Of My Oil Leak? guys with a three day weekend coming up I want to tackle this job, but I have no idea where to start, do I pull the tranny off and remove the bell housing and inspect that area, or do I drop the oil pan (again) and that's where the rear main oil seal lives

02-10-2015, 04:35 AM	#8
Chaplain Registered User Join Date: Oct 2014 Location: TN Posts: 294	Re: No Way Is This The Source Of My Oil Leak? I have no idea where the source of your oil is but just from watching your other post, I don't think you're going stop until you have the engine and trans out. I'm just saying. Besides that's what I'm doing.

02-10-2015, 08:07 AM	#9
homemade87 Registered User Join Date: Apr 2010 Location: Guntersville Alabama Posts: 1,073	Re: No Way Is This The Source Of My Oil Leak? From the looks of the inside of the bell housing my guess would be the rear main seal . If you have a 2-piece rear main seal I would drop the oil pan and replace it. I see a blue edge on the oil pan . Is that one of felpro one piece gaskets . If so you should be able to reuse it . If you have a one piece seal this is not an option . You will have to drop the trans. Just take a good look at the top rear of the engine before you do this . Make sure there is no oil coming from a oil sending unit, valve covers or intake seal . My guess there is not . You would see more evidence of oil on the outside of the bell housing . Hope all goes well .



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