| Common front of engine oil leaks [message #345808] |
Mon, 29 July 2019 08:59  |
Will Albers
Messages: 183
Registered: November 2017
Location: Detroit MI (Belleville)
Karma: 2
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I have wonderful auto administered undercoating that loves to drip from the engine, and down onto the main crossmember below the fan. There is so much built up, that i expect this has been going on for a while. I've replaced the valve cover gaskets, and can now verify they are not the source. The oil doesnt seem biased to one side or another. The whole front of the engine is wet from mid point down.
Is it possible to spring a leak at the intake to head surface? Is it more likely a leak behind the timing gear, or possibly pulleys? What are the more common leaks from the front of a 403?
For what it is worth, my coolant and oil are clean. Not burning any noticeable amounts.
Thanks
-Will
1978 Palm Beach.
Detroit Michigan
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| Re: Common front of engine oil leaks [message #345812 is a reply to message #345808] |
Mon, 29 July 2019 09:13  |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Start with easy stuff--oil gauge sender. They can leak where press assembled. Since up high in front and oil flows with gravity and fan wind-- well you get the picture
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Common front of engine oil leaks [message #345819 is a reply to message #345808] |
Mon, 29 July 2019 09:56 |
Scott Nutter
Messages: 782
Registered: January 2015
Location: Houston/San Diego
Karma: 4
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I've had a similar issue on my 455. Turned out to be the front intake manifold seal..
Scott.
Scott Nutter
1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI
Houston, Texas
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| Re: [GMCnet] Common front of engine oil leaks [message #345821 is a reply to message #345819] |
Mon, 29 July 2019 11:24 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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Take some break cleaner and clean the mess a the top area ad work down.
On Mon, Jul 29, 2019 at 8:04 AM Scott Nutter via Gmclist <
gmclist@list.gmcnet.org> wrote:
> I've had a similar issue on my 455. Turned out to be the front intake
> manifold seal..
> Scott.
> --
> Scott Nutter
> 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final
> drive, Quad bags, tankless water heater, everything Lenzi. Alex Ferrera
> installed MSD Atomic EFI
> Houston, Texas
>
> _______________________________________________
> GMCnet mailing list
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: Common front of engine oil leaks [message #345846 is a reply to message #345808] |
Tue, 30 July 2019 07:21 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Front intake manifold gasket / seal. It is really is a rubber seal or if it has been replaced it is a smashed silicone bead. If necessary, It is possible to reseal it without removing the manifold. Clean the area thoroughly with brake cleaner. Then coat the seam with silicone and apply a shop vac to the oil fill tube with the PCV valve removed and taped off. It is not pretty but it works.
There should be no or minimal pressure in there but if the PCV is not working then crankcase pressure will build up and leak through the weakest point. I would replace the PCV first to see if it makes any difference. It is cheap and easy.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Common front of engine oil leaks [message #345849 is a reply to message #345846] |
Tue, 30 July 2019 08:09 |
Will Albers
Messages: 183
Registered: November 2017
Location: Detroit MI (Belleville)
Karma: 2
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Senior Member |
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Thanks Ken! That vacuum idea is a great one!
On Tue, Jul 30, 2019 at 8:53 AM Ken Burton via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Front intake manifold gasket / seal. It is really is a rubber seal or if
> it has been replaced it is a smashed silicone bead. If necessary, It is
> possible to reseal it without removing the manifold. Clean the area
> thoroughly with brake cleaner. Then coat the seam with silicone and apply
> a shop
> vac to the oil fill tube with the PCV valve removed and taped off. It is
> not pretty but it works.
>
> There should be no or minimal pressure in there but if the PCV is not
> working then crankcase pressure will build up and leak through the weakest
> point. I would replace the PCV first to see if it makes any difference.
> It is cheap and easy.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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1978 Palm Beach.
Detroit Michigan
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