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6K Onan oil leak [message #304645] Sun, 31 July 2016 17:05 Go to next message
skip2 is currently offline  skip2   United States
Messages: 544
Registered: September 2011
Location: Winter Haven,FL (center o...
Karma: 3
Senior Member
Good evening all,
My old Onan has finally gave me a problem this weekend, never had any problem since I got it all fix up 4 years ago. Started pouring oil out of the hot air exhaust narrowed it down to behind the flywheel then after several wipedowns and flywheel ons and offs so I could run it, it appears to be coming from the lower right area of the cam and crank gear cover.
First thought it was the bolt on the bottom right with it's 2 brass seal washers on each side of the wire bracket thats under it, checked and it was clean and tight. Ran and appears to be coming out in the area behind it, under pressure at the rate its leaking. The only thing in that area is the cover gasket. Is there an oil passage in that area or is that gasket a known problem area? The biggest problem to nail it down is that the flywheel has to be installed to run it. Any ideals or experiences out there.
Thanks.
Skip Hartline


74 Canyon Lands, FiTech, 3.7 FD LSD, Manny Tranny, Springfield Distributor, 2001 Chevy Tracker Ragtop Towd
Re: 6K Onan oil leak [message #304646 is a reply to message #304645] Sun, 31 July 2016 17:14 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
Messages: 4508
Registered: April 2011
Karma: 39
Senior Member
skip2 wrote on Sun, 31 July 2016 17:05
Good evening all,
My old Onan has finally gave me a problem this weekend, never had any problem since I got it all fix up 4 years ago. Started pouring oil out of the hot air exhaust narrowed it down to behind the flywheel then after several wipedowns and flywheel ons and offs so I could run it, it appears to be coming from the lower right area of the cam and crank gear cover.
First thought it was the bolt on the bottom right with it's 2 brass seal washers on each side of the wire bracket thats under it, checked and it was clean and tight. Ran and appears to be coming out in the area behind it, under pressure at the rate its leaking. The only thing in that area is the cover gasket. Is there an oil passage in that area or is that gasket a known problem area? The biggest problem to nail it down is that the flywheel has to be installed to run it. Any ideals or experiences out there.
Thanks.
Skip Hartline
The manual for my 4kw Onan says:

"CRANKCASE BREATHER
This engine uses a crankcase breather valve for maintaining crankcase vacuum . No maintenance is generally required. If the crankcase becomes pressurized as evidenced by oil leaks at the seals, clean baffle and valve in a suitable solvent. Crankcase breather disassembly requires removal of exhaust manifold. See Figure 27."
Re: [GMCnet] 6K Onan oil leak [message #304647 is a reply to message #304645] Sun, 31 July 2016 17:12 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
If it suddenly started leaking, I would check the valve cover with the hose
on it. Remove the cover and check the spring loaded disc valve. Also check
the hose. Might as well check the oil filler cork gasket too. JWIWD.
Jim Hupy
Salem, Or.
On Jul 31, 2016 3:06 PM, "Skip Hartline" wrote:

> Good evening all,
> My old Onan has finally gave me a problem this weekend, never had any
> problem since I got it all fix up 4 years ago. Started pouring oil out of
> the
> hot air exhaust narrowed it down to behind the flywheel then after several
> wipedowns and flywheel ons and offs so I could run it, it appears to be
> coming from the lower right area of the cam and crank gear cover.
> First thought it was the bolt on the bottom right with it's 2 brass seal
> washers on each side of the wire bracket thats under it, checked and it was
> clean and tight. Ran and appears to be coming out in the area behind it,
> under pressure at the rate its leaking. The only thing in that area is the
> cover gasket. Is there an oil passage in that area or is that gasket a
> known problem area? The biggest problem to nail it down is that the flywheel
> has to be installed to run it. Any ideals or experiences out there.
> Thanks.
> Skip Hartline
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] 6K Onan oil leak [message #304648 is a reply to message #304645] Sun, 31 July 2016 17:17 Go to previous messageGo to next message
emerystora is currently offline  emerystora   United States
Messages: 4442
Registered: January 2004
Karma: 13
Senior Member
Check the gaskets on both sides of the right support that is located directly behind the oil filter. The oil passages to and from the oil filter go through the bracket.
First try tightening the bolts. That might fix the leaks. If not you'll have to replace the gaskets. Easy to make your own from gasket material. Don't use cork.

If you find that you have to replace the seal on the shaft behind the flywheel let me know as I've found a source for a better deal which las a double lip and a spring inside that allows the seal to seal better

Emery Stora
77 Kingsley
Frederick, CO

> On Jul 31, 2016, at 4:05 PM, Skip Hartline wrote:
>
> Good evening all,
> My old Onan has finally gave me a problem this weekend, never had any problem since I got it all fix up 4 years ago. Started pouring oil out of the
> hot air exhaust narrowed it down to behind the flywheel then after several wipedowns and flywheel ons and offs so I could run it, it appears to be
> coming from the lower right area of the cam and crank gear cover.
> First thought it was the bolt on the bottom right with it's 2 brass seal washers on each side of the wire bracket thats under it, checked and it was
> clean and tight. Ran and appears to be coming out in the area behind it, under pressure at the rate its leaking. The only thing in that area is the
> cover gasket. Is there an oil passage in that area or is that gasket a known problem area? The biggest problem to nail it down is that the flywheel
> has to be installed to run it. Any ideals or experiences out there.
> Thanks.
> Skip Hartline
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] 6K Onan oil leak [message #304649 is a reply to message #304648] Sun, 31 July 2016 17:27 Go to previous messageGo to next message
wally is currently offline  wally   United States
Messages: 643
Registered: August 2004
Location: Omaha Nebraska
Karma: 5
Senior Member
If is the mount and oil filter adapter gaskets Onan has a newer design gasket like this
http://www.gmcmhphotos.com/photos/onan-oil-filter-adapter-gasket/p17826.html
It takes two gaskets one on each side of the mount strap.
emerystora wrote on Sun, 31 July 2016 17:17
Check the gaskets on both sides of the right support that is located directly behind the oil filter. The oil passages to and from the oil filter go through the bracket.
First try tightening the bolts. That might fix the leaks. If not you'll have to replace the gaskets. Easy to make your own from gasket material. Don't use cork.

If you find that you have to replace the seal on the shaft behind the flywheel let me know as I've found a source for a better deal which las a double lip and a spring inside that allows the seal to seal better

Emery Stora
77 Kingsley
Frederick, CO

> On Jul 31, 2016, at 4:05 PM, Skip Hartline wrote:
>
> Good evening all,
> My old Onan has finally gave me a problem this weekend, never had any problem since I got it all fix up 4 years ago. Started pouring oil out of the
> hot air exhaust narrowed it down to behind the flywheel then after several wipedowns and flywheel ons and offs so I could run it, it appears to be
> coming from the lower right area of the cam and crank gear cover.
> First thought it was the bolt on the bottom right with it's 2 brass seal washers on each side of the wire bracket thats under it, checked and it was
> clean and tight. Ran and appears to be coming out in the area behind it, under pressure at the rate its leaking. The only thing in that area is the
> cover gasket. Is there an oil passage in that area or is that gasket a known problem area? The biggest problem to nail it down is that the flywheel
> has to be installed to run it. Any ideals or experiences out there.
> Thanks.
> Skip Hartline
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Wally Anderson
Omaha NE
75 Glenbrook
Re: [GMCnet] 6K Onan oil leak [message #304660 is a reply to message #304645] Sun, 31 July 2016 20:59 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Skip,
Not sure, but the seal on the shaft might not be the problem but the Oil
filter mount.
I need to heck with our technician and see what your eluding to is the
problem.

On Sun, Jul 31, 2016 at 3:05 PM, Skip Hartline
wrote:

> Good evening all,
> My old Onan has finally gave me a problem this weekend, never had any
> problem since I got it all fix up 4 years ago. Started pouring oil out of
> the
> hot air exhaust narrowed it down to behind the flywheel then after several
> wipedowns and flywheel ons and offs so I could run it, it appears to be
> coming from the lower right area of the cam and crank gear cover.
> First thought it was the bolt on the bottom right with it's 2 brass seal
> washers on each side of the wire bracket thats under it, checked and it was
> clean and tight. Ran and appears to be coming out in the area behind it,
> under pressure at the rate its leaking. The only thing in that area is the
> cover gasket. Is there an oil passage in that area or is that gasket a
> known problem area? The biggest problem to nail it down is that the flywheel
> has to be installed to run it. Any ideals or experiences out there.
> Thanks.
> Skip Hartline
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Jim Kanomata
Applied/GMC, Fremont,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
Re: [GMCnet] 6K Onan oil leak [message #304858 is a reply to message #304660] Wed, 03 August 2016 18:48 Go to previous messageGo to next message
Tony Cook is currently offline  Tony Cook   United States
Messages: 121
Registered: August 2014
Location: Torrance CA
Karma: 0
Senior Member
Just corrected this same issue with my 6k thanks to you all here it was blowing oil out the same. Ended up finding it was coming from the oil filter adapter just needed titend up . Thanks you guys for the wisdom.

Tony Cook 77' Kingsley ' SuperSession 77 ' Torrance Beach,CA
Re: 6K Onan oil leak [message #305028 is a reply to message #304645] Sat, 06 August 2016 18:48 Go to previous message
skip2 is currently offline  skip2   United States
Messages: 544
Registered: September 2011
Location: Winter Haven,FL (center o...
Karma: 3
Senior Member
Got around to working on the leaking Onan today. Got new gaskets for the oil filter adapter replaced them and still leaked but this time I had the air shroud off to get to the adapter and saw the oil was coming out of the oil pressure switch and running down it's lead. The adapter gaskets were needing replacing anyway, very brittle. Just wanted to pass on what I found and to thank all who made suggestions and headed me in the right direction.
Skip Hartline


74 Canyon Lands, FiTech, 3.7 FD LSD, Manny Tranny, Springfield Distributor, 2001 Chevy Tracker Ragtop Towd
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