oil leakage small block chevy - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 05-12-2009, 08:47 PM
Registered User
 
Join Date: Mar 2009
Location: sparks, nv.
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
oil leakage small block chevy

i have a small block 350 chevy motor that is leaking oil like a sponge and im having a real problem finding where from. the pan gasket is not leaking, the pressure guage is fine, the front and rear seals are fine, and the valve covers are fine. it appears there is wetness around the cylinder heads and also running down the transmission housing from the rear of the engine. im wondering if the heads could be seaping yet still run fantastic..no smoke, doesnt use water. any suggestions before i tear into the motor. oh and this is a brand new rebuilt engine just assembled and installed. thanks tony !

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-12-2009, 08:57 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 8,959
Wiki Edits: 0

Thanks: 20
Thanked 378 Times in 347 Posts
The seal at the back of the intake where it meets the block? Common leak spot.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-12-2009, 09:00 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,654
Wiki Edits: 0

Thanks: 15
Thanked 58 Times in 55 Posts
Look on the front of the engine by the harmonic balancer, beside it on both sides you`ll see 2 bolt holes. These were put there for the original mounting points for the engine, however, the top bolt hole on the passengers side runs into the fuel pump push rod, if there`s not a bolt in this hole, oil will come out of this hole off idle. Often a short bolt with sealant is put in this hole as if the bolt is too long it`ll make contact with the fuel pump push rod.
Here`s a example:
http://www.chevytalk.org/fusionbb/pr...hp?tid/182728/
Check to see if this bolt is in place.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-12-2009, 09:01 PM
fast68's Avatar
likes chevy trucks & boobies
 
Last photo:
Join Date: Oct 2005
Location: IL
Posts: 1,970
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
and distributor base gasket is a common one as well, sometimes it is forgotten about
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-12-2009, 10:42 PM
Registered User
 
Join Date: Apr 2009
Location: hillsboro, tx
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
chevy oil leak

check to see if the oil pressure sender is tight and sealed. sometimes during installation the sender can get cracked or loosened.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-13-2009, 09:10 AM
Registered User
 
Join Date: Mar 2009
Location: sparks, nv.
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
it does have the bolts by the fuel pump and not leaking and also the dist. is fine and the sending unit is fine. the intake gasket sounds like a good possibility and ill check that next. however nobody has ruled out for me the possibility of the head seapage question ?. could someone please address that question. thanks for the input Tony!
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-13-2009, 09:18 AM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,654
Wiki Edits: 0

Thanks: 15
Thanked 58 Times in 55 Posts
Oil only drains back into the block via the drain holes, there`s no other place for it to go, if it were coming out of the gaskets it would have to travel a long way. Since you have it on both sides of the engine it sounds like the valve cover gaskets, if you can remove a spark plug and find oil on the threads you found the problem. The oil will leak out from under the gaskets, down the head and fly back from there. Are you using a PCV system?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-13-2009, 10:21 AM
Registered User
 
Join Date: Mar 2009
Location: sparks, nv.
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
the valve covers are completely dry all the way around and there is no oil above headers, only below. yes i am running pcv.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-13-2009, 10:28 AM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,654
Wiki Edits: 0

Thanks: 15
Thanked 58 Times in 55 Posts
Sorry Tony, I`m stumped.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-13-2009, 11:38 AM
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Central UT
Posts: 64
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
When the engine was re-built, did they use the rubber gaskets for the front and back of the intake manifold? If they did, chances are that's where it's leaking. If there's been any machining on the head/block/intake, they won't seal. If it's a rebuild that you paid for, make them fix it. If not, it's not that big of deal to pull the intake and seal it.

http://www.hotrod.com/techarticles/m...end_seals.html

The spec for the gap between the block and intake ends is 0.090". Most of the ones that I've seen aren't anywhere near that. I've seen them as small as 0.030 and as wide as 1/4". On the last one, we got the intake machined to get it down to 1/8".

Matt
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 05-13-2009, 12:40 PM
Registered User
 
Join Date: Nov 2004
Location: California
Age: 67
Posts: 828
Wiki Edits: 0

Thanks: 27
Thanked 21 Times in 19 Posts
Is the leak particularly heavy and noticable on the left side? There is a pressure line plug installed in a pipe tapped hole on the rear of the head deck surface, in the block, but approximately at the #7 Exhaust valve pushrod location, aft of the head. Usually, about half of the plug is visible, and half is hidden below the cylinder head. The plug might be loose and leaking.

Pat
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 05-13-2009, 01:51 PM
Registered User
 
Join Date: Mar 2009
Location: sparks, nv.
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
well if the plug were loose or leaking that would mean head removal...correct?
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 05-13-2009, 01:53 PM
Registered User
 
Join Date: Nov 2004
Location: California
Age: 67
Posts: 828
Wiki Edits: 0

Thanks: 27
Thanked 21 Times in 19 Posts
I've not seen one that could be tightened with the head in place. Verify before you disassemble.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 05-13-2009, 03:22 PM
Registered User
 
Last photo:
Join Date: Oct 2007
Location: Northern Ohio
Age: 58
Posts: 81
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I,m betting on the intake seal, I had one that I was not getting a big enough silicone bead and it would leak again. I was always able to get my hand to the back of the block and run my finger along and I would find the oil running down the back of the block onto the starter and dripping. the oil pan and seals were not the problem. As stated above, make sure the distributor seal is not also leaking. It took me three different times before I finally got the silicone beads correct for that motor. Good luck.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 05-14-2009, 10:52 AM
bobjob's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: florence az.
Age: 60
Posts: 295
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
this sounds a little strange... but hows the exhaust system? if muffler or cat. converter is plugged-up.. backpressure in engine will increase and start blowing oil out of everywhere .just a guess and i'm probably wrong! guess i just need to work on typing skills.
had a few do same thing, spent a few too many dollars and time chasing leaks before i found problem.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
big block or small block chevy 69YENKONOVA Engine 81 05-13-2010 07:26 AM
Why I have Always LOVED the Small Block Chevy A glimpse inside reality Rob Keller Hotrodders' Lounge 54 11-09-2007 07:30 PM
My 350 Small Block Chevy. What do I have? Frank the Tank Engine 29 09-08-2007 06:33 PM
7qt Oil Pan & Pickup SBC Small Block Chevy Mustangsaly Engine 6 06-12-2005 07:52 PM
need info on small block chevys engine-rookie Engine 1 05-03-2003 08:48 PM


All times are GMT -6. The time now is 08:42 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.