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engine oil leak question from new owner [message #167565] Wed, 25 April 2012 19:16 Go to next message
jamescbarnett is currently offline  jamescbarnett   United States
Messages: 4
Registered: April 2012
Location: Seattle WA
Karma: 0
Junior Member
So I bought a 76 GMC in Phoenix and immediately drove it to Seattle. On the way, just before LA, I noticed an oil leak, about 1 drip per second, coming from the back of the oil pan, kind of up behind the starter. I crawled under it at some truck stop and started tightening up oil pan bolts that I could reach. It seemed to stop the problem for a while, until I got to Newark, CA. I then stopped in at Applied GMC, and had them look the MH over, They said it was hard to tell where the leak was coming from, maybe oil pan gasket, maybe higher up in the engine. They tightened up the oil pan bolts I couldn't reach with my limited tools. Around Oregon Sand Dunes it started leaking again, and I noticed it's left a small puddle on the street where it is now parkedi in Seattle. Motor is original, and has 130k on it, and has been very well maintained.

I already have a dump truck and a backhoe with an oil leak, and I don't want a Motorhome with one too. I noticed that changing the oil pan gasket is no easy task. Is there any other gasket I should be changing while I have the oil pan off? And what is the easiest way to get the oil pan off? Raise the engine? lower the front wheel drive? Thanks in advance!

James
Re: engine oil leak question from new owner [message #167567 is a reply to message #167565] Wed, 25 April 2012 20:04 Go to previous messageGo to next message
Chr$ is currently offline  Chr$   United States
Messages: 2690
Registered: January 2004
Location: Scottsdale, AZ
Karma: 1
Senior Member
James, Are you the gentleman I spoke to last week? Happy to hear you made it home.

Problem with the oil pan is you need to drop the tranny to replace the gasket. If you do, get the olds diesel V8 motor gasket. it fits and is thicker.

As for leaks, well, it is a 77. I have given up on having a leak free powertrain. At least i was able to fix the smelly valve cover leak. Intake is next...


-Chr$: Perpetual SmartAss
Scottsdale, AZ

77 Ex-Kingsley 455 SOLD!
2010 Nomad 24 Ft TT 390W PV W/MPPT, EV4010 and custom cargo door.
Photosite: Chrisc GMC:"It has Begun" TT: "The Other Woman"
Re: [GMCnet] engine oil leak question from new owner [message #167573 is a reply to message #167565] Wed, 25 April 2012 20:28 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

Here's a message I sent into the GMCnet awhile back.

Been there done that, you must remove the transmission / final drive to get
to the bolts on the final drive side of the oil pan.

Suggestions:

1) while you've got the pan off check the oil pickup for crud:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=10860

Thanks KelvinD!

2) while you've got the pan out add a second drain in the front part:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=31708

http://www.gmcmhphotos.com/photos/showphoto.php?photo=10340

http://www.gmcmhphotos.com/photos/showphoto.php?photo=10341

Thanks BobS!

3) make sure to check the rear main seal for leakage if it is leaking use a
Ford 460 rubber main seal to replace it:

http://www.gmcmhphotos.com/photos/showphoto.php?photo=10859

Thanks KelvinD - again!

4) use a 350 diesel oil pan seal it is a sandwich with a metal center that
will not creep out.

Auto-Zone shows Fel-Pro oil pan gasket # OS30471C as standard for the 350
diesel and is shown as optional for the 455 and 403.

Thanks ChuckB!

5) make sure that the gasket seating surface is flat and that where the
bolts go through are not raised, I tapped each one down a bit with two
hammers; the round end of a ball peen hammer in the bolt hole and tapped the
flat end with another hammer which dimpled them inwards away from the seal.
When you torque the bolts to 10 ft lb (ref. MM X-7525 pg 6A-66) it will pull
level again. Let it sit overnight and torque them again the next morning.

6) apply a sealant to the pan before you put the gasket on to keep it in
place so it doesn't move. You can also tie it in place using thread through
holes at each end.

I used:

http://tinyurl.com/yhj8de


http://www.permatex.com/products/automotive/automotive_gasketing/gasket_seal
ants/auto_Permatex_Aviation_Form-A-Gasket_No_3_Sealant_a.htm

Thanks MannyT!

7) the gasket has "notches" cut out where the rubber front and rear seals
interface with it; apply some silicone sealant there.

Can't think of anything else at the moment, if anybody else can please
mention it!

Regards,
Rob M.

-----Original Message-----
From: James Barnett

So I bought a 76 GMC in Phoenix and immediately drove it to Seattle. On
the way, just before LA, I noticed an oil leak, about 1 drip per second,
coming from the back of the oil pan, kind of up behind the starter. I
crawled under it at some truck stop and started tightening up oil pan bolts
that I could reach. It seemed to stop the problem for a while, until I got
to Newark, CA. I then stopped in at Applied GMC, and had them look the
MH over, They said it was hard to tell where the leak was coming from,
maybe oil pan gasket, maybe higher up in the engine. They tightened up the
oil pan bolts I couldn't reach with my limited tools. Around Oregon Sand
Dunes it started leaking again, and I noticed it's left a small puddle on
the street where it is now parkedi in Seattle. Motor is original, and has
130k on it, and has been very well maintained.

I already have a dump truck and a backhoe with an oil leak, and I don't want
a Motorhome with one too. I noticed that changing the oil pan gasket is
no easy task. Is there any other gasket I should be changing while I have
the oil pan off? And what is the easiest way to get the oil pan off?
Raise the engine? lower the front wheel drive? Thanks in advance!

James

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] engine oil leak question from new owner [message #167583 is a reply to message #167565] Wed, 25 April 2012 21:27 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
James,

Lots of good suggestions, especially Rob's Hamilton Standard manual. But
no one's yet asked: Are you SURE it's engine oil & not transmission fluid?
Don't depend on ATF being red by the time it reaches the ground (or even
in the transmission, for that matter). It can easily leak from the area
you first described. Be certain you know what you're chasing.

Oh yeah -- welcome to the Zoo!

Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com



On Wed, Apr 25, 2012 at 8:16 PM, James Barnett <jamescbarnett@yahoo.com>wrote:

>
>
> So I bought a 76 GMC in Phoenix and immediately drove it to Seattle. On
> the way, just before LA, I noticed an oil leak, about 1 drip per second,
> coming from the back of the oil pan, kind of up behind the starter...
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: engine oil leak question from new owner [message #167586 is a reply to message #167565] Wed, 25 April 2012 21:37 Go to previous messageGo to next message
John Sharpe is currently offline  John Sharpe   United States
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
Senior Member
Quote:

,,,,hard to tell where the leak was coming from, maybe oil pan gasket, maybe higher up in the engine.,,,,


It flows down hill. Try to get it cleaned off to tell. I would suggest that you start by looking carefully at the valve cover gaskets. If no oil under them then the leak is lower. Be aware the fan can blow oil from the front of the engine toward the rear.


John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
Re: engine oil leak question from new owner [message #167587 is a reply to message #167565] Wed, 25 April 2012 21:39 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
My money is not on the pan gasket as there are so many other place to leak. Snugging the pan bolts should stop the leak if the gasket is still there in one piece. Check oil cooler addaptor and cooler lines and pressure sender as well.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: engine oil leak question from new owner [message #167589 is a reply to message #167587] Wed, 25 April 2012 22:13 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
Messages: 7111
Registered: November 2004
Location: Dexter, Mo.
Karma: 207
Senior Member
I am sure Jim had his guys check the oil filter/oil cooler lines adapter but it sure sounds like that might be the problem. On this last engine, mine did not get tightened up enough. After 750 miles I snugged the nut and the two, or three, bolts. That stopped my problem.
Welcome. Glad you found us.
Dan


3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer
Re: engine oil leak question from new owner [message #167590 is a reply to message #167586] Wed, 25 April 2012 22:24 Go to previous messageGo to next message
mike miller   United States
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
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Senior Member
John Sharpe wrote on Wed, 25 April 2012 19:37

Quote:

,,,,hard to tell where the leak was coming from, maybe oil pan gasket, maybe higher up in the engine.,,,,


It flows down hill. Try to get it cleaned off to tell. ...


You could try the trick that I first learned about at the Spring GMCMI Convention (@Shawnee). Spray on some foot powder over the suspect area, drive it a bit and look for tracks in the powder.

You can use any cheap powder you find in spray cans... like this: <http://www.dollartree.com/Dr-Foot-Foot-Powder-Spray-4-oz-/p300999/index.pro>

I had never heard of this before but it worked like a charm on Marc's oil leak.

When you KNOW what is wrong, it is easier to fix. Twisted Evil

OBTW: Welcome to the nut house.... You most likely drove by my house on your way north. Get a copy of the Black list (aka: GMC Assist List) for future travels. <http://www.bdub.net/Black_List/>


Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo' http://m000035.blogspot.com
Re: engine oil leak question from new owner [message #167593 is a reply to message #167565] Wed, 25 April 2012 23:15 Go to previous messageGo to next message
George Beckman is currently offline  George Beckman   United States
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Registered: October 2008
Location: Colfax, CA
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Senior Member
jamescbarnett wrote on Wed, 25 April 2012 17:16

So I bought a 76 GMC in Phoenix and immediately drove it to Seattle. On the way, just before LA, I noticed an oil leak, about 1 drip per second, coming from the back of the oil pan, kind of up behind the starter. I crawled under it at some truck stop and started tightening up oil pan bolts that I could reach. It seemed

Thanks in advance!

James


I too am guessing it is not the pan. My drip, showing up around the starter was coming from the oil filter adaptor- where it bolts to the engine block. There are three bolts that hold it and if I remember right they are not all the same length. (I may have dreamed that, but note which bolt came from which part of the bracket.) Anyway, I pulled the whole thing off, cleaned the surface, put it back on using The Right Stuff and no more leak.

Because of the turbulence from the wind and fan, oil was everywhere. It seemed like there was more on the left muffler than the right and yet the leak was on the right side of the engine.



'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
Re: engine oil leak question from new owner [message #167595 is a reply to message #167589] Wed, 25 April 2012 23:21 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
Let start looking up high and work down. I would look at the valve cover gaskets first. If you replace them one company makes a gasket that is a steel piece sandwiched between two pieces of cork. I forgot who it was but they are available. Then look at the back of the intake manifold for leaks. After that I would replace the oil filter / oil cooler adapter gaskets. They are an easy job.

I would remove the wheel liners and leave them off until you have found and fixed the leak(s). This makes it easy to see most of the engine and see where a leak is coming from with the engine at an idle. It also makes it easy to get to the engine and clean it periodically with engine cleaner, or simple green and water, or a pressure washer.

If it really is coming from the back of the pan (no oil traces above there,) then I would be looking for a rear main seal leak rather than an oil pan gasket.

Good luck on your hunt.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] engine oil leak question from new owner [message #167611 is a reply to message #167565] Thu, 26 April 2012 07:21 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
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Registered: May 2006
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Senior Member
James,
Before you go to the major task of dropping the pan, check both valve
covers. You mentioned that it is coming from above the starter. Eliminate
the easy fixes first.

On Wed, Apr 25, 2012 at 5:16 PM, James Barnett <jamescbarnett@yahoo.com>wrote:

>
>
> So I bought a 76 GMC in Phoenix and immediately drove it to Seattle. On
> the way, just before LA, I noticed an oil leak, about 1 drip per second,
> coming from the back of the oil pan, kind of up behind the starter. I
> crawled under it at some truck stop and started tightening up oil pan bolts
> that I could reach. It seemed to stop the problem for a while, until I
> got to Newark, CA. I then stopped in at Applied GMC, and had them look
> the MH over, They said it was hard to tell where the leak was coming from,
> maybe oil pan gasket, maybe higher up in the engine. They tightened up the
> oil pan bolts I couldn't reach with my limited tools. Around Oregon Sand
> Dunes it started leaking again, and I noticed it's left a small puddle on
> the street where it is now parkedi in Seattle. Motor is original, and
> has 130k on it, and has been very well maintained.
>
> I already have a dump truck and a backhoe with an oil leak, and I don't
> want a Motorhome with one too. I noticed that changing the oil pan
> gasket is no easy task. Is there any other gasket I should be changing
> while I have the oil pan off? And what is the easiest way to get the oil
> pan off? Raise the engine? lower the front wheel drive? Thanks in
> advance!
>
> James
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
Fathom the hypocrisy of a nation where every citizen must prove they have
health insurance......but not everyone has to prove they're a citizen.
Steve Ferguson
Sierra Vista, AZ
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Re: engine oil leak question from new owner [message #167630 is a reply to message #167565] Thu, 26 April 2012 11:56 Go to previous message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
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Senior Member
jamescbarnett wrote on Wed, 25 April 2012 20:16

So I bought a 76 GMC in Phoenix and immediately drove it to Seattle. On the way, just before LA, I noticed an oil leak, about 1 drip per second, coming from the back of the oil pan, kind of up behind the starter. I crawled under it at some truck stop and started tightening up oil pan bolts that I could reach. It seemed to stop the problem for a while, until I got to Newark, CA. I then stopped in at Applied GMC, and had them look the MH over, They said it was hard to tell where the leak was coming from, maybe oil pan gasket, maybe higher up in the engine. They tightened up the oil pan bolts I couldn't reach with my limited tools. Around Oregon Sand Dunes it started leaking again, and I noticed it's left a small puddle on the street where it is now parkedi in Seattle. Motor is original, and has 130k on it, and has been very well maintained.

I already have a dump truck and a backhoe with an oil leak, and I don't want a Motorhome with one too. I noticed that changing the oil pan gasket is no easy task. Is there any other gasket I should be changing while I have the oil pan off? And what is the easiest way to get the oil pan off? Raise the engine? lower the front wheel drive? Thanks in advance!

James

James,

Welcome to the Group/Family/Cult/Asylum.

Unfortunately, as having once been the aftermarket guy for a major gasket supplier, 36 years and 130k miles is a lot to ask of any seal or gasket.

The idea of cleaning the engine you can see and spraying it with tracing (foot) powder is a real good start. That way you will be certain that the leak is not above the pan rail.

I can attest to the fact that even without the proper facilities it is not all that tough to get the transmission and final drive down. But, as others have said, be real sure you need to before you do that. Get the plan for a translifter that KenH put together. I can't find a link or pictures. (I can barely find my own pictures.) You will want to add a drain to the transmission pan if you take it down. You will also want to replace the double hex high grade fasteners at the inboard ends of the drive axles.

It appears that you are well on you way anyway, but I like to offer a greeting to all new owners because we have found the GMC to be much more than just something you own. It will be come a part of your life much as the boat is to a waterman. So, I paraphrase a traditional greeting to a new vessel or owner.

May the Good Lord bless this coach and all those that set forth within her.

Welcome James

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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