LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Mystery leak under head.

Thread Tools
 
Search this Thread
 
Old Apr 17, 2017 | 07:34 PM
  #1  
350 groundpounder's Avatar
Thread Starter
TECH Fanatic
10 Year Member
Liked
Loved
Community Favorite
iTrader: (5)
 
Joined: Jan 2014
Posts: 1,157
Likes: 28
From: Michigan
Default Mystery leak under head.

See pics, i have 1500 miles on cam swap. Milled heads, fel pro 1074's, arp head bolts with permatex high temp thread sealant. Ewp. Seems to be mystery oil coming from between the head and block?
Attached Thumbnails Mystery leak under head.-20170417_185407.jpg   Mystery leak under head.-20170417_185423.jpg  
Reply
Old Apr 17, 2017 | 08:24 PM
  #2  
Nostang's Avatar
TECH Enthusiast
20 Year Member
iTrader: (4)
 
Joined: Oct 2003
Posts: 544
Likes: 3
From: Gilbert, AZ
Default

That looks like a slight coolant leak to me. Might want to try a little stop leak or else you will have to pull it apart to fix it.
Reply
Old Apr 17, 2017 | 09:17 PM
  #3  
Badazz 97 TA's Avatar
TECH Addict
iTrader: (18)
 
Joined: Aug 2007
Posts: 2,169
Likes: 2
From: Arizona
Default

If it is coolant i definitaly don't recommend using stop leak on it. do it right and fix the problem the correct way. If it is leaking in the engine you could pull the plug near it and see if its steam cleaned compared to the other plugs or of your losing coolant check the dip stick or oil.
Reply
Old Apr 17, 2017 | 09:39 PM
  #4  
350 groundpounder's Avatar
Thread Starter
TECH Fanatic
10 Year Member
Liked
Loved
Community Favorite
iTrader: (5)
 
Joined: Jan 2014
Posts: 1,157
Likes: 28
From: Michigan
Default

Def looks like oil to me not coolant? Hard to say. I cant believe it would be coolant. I put everything together correctly. If it was coolant, those gm tabs might stop it. Its not even leaking enough to cause a drip in the garage. Will check plugs though. Oil looked good.
Reply
Old Apr 18, 2017 | 09:30 AM
  #5  
SS RRR's Avatar
Village Troll
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Oct 2002
Posts: 11,111
Likes: 598
From: Jackstandican
Default

If it is coolant you should be able to smell it burning either in the engine bay or inside the car, especially if the engine is at operating temp, you are stopped long enough for fumes to collect inside the engine bay and then take off.

Last edited by SS RRR; Apr 18, 2017 at 09:55 AM.
Reply
Old Apr 18, 2017 | 11:30 AM
  #6  
350 groundpounder's Avatar
Thread Starter
TECH Fanatic
10 Year Member
Liked
Loved
Community Favorite
iTrader: (5)
 
Joined: Jan 2014
Posts: 1,157
Likes: 28
From: Michigan
Default

Yeah i cant smell anything. I will be driving it to work today "50mile round trip" then i can check it tonight. I think it might be oil running down from front of intake along the block. More investigation is needed. This didnt start until i put synthetic oil back in after 700miles after build. Switched back to dino oil needless to say. Engine was dry as a bone on dino oil up to 700 miles.
Reply
Old Apr 18, 2017 | 11:59 AM
  #7  
SS RRR's Avatar
Village Troll
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Oct 2002
Posts: 11,111
Likes: 598
From: Jackstandican
Default

**** synthetic oil. Just run conventional and change religiously.
Reply
Old Apr 18, 2017 | 04:49 PM
  #8  
craby's Avatar
Teching In
 
Joined: Aug 2013
Posts: 33
Likes: 0
From: Tokeland
Default

clean it with some brake clean or something like that. then see if you can track it better. may be a burn off of something used to assemble and wont come back.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old Apr 18, 2017 | 04:54 PM
  #9  
pdxmotorhead's Avatar
TECH Addict
5 Year Member
 
Joined: Oct 2016
Posts: 2,513
Likes: 480
From: PDX-OR-USA
Default

I just did a head on a Honda, and it let just a little oil out then stopped, I think it was the MLS gasket heat cycling in to place. (Honda uses a gasket just like a LS MLS one.. )
Reply
Old Apr 18, 2017 | 05:03 PM
  #10  
SS RRR's Avatar
Village Troll
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Oct 2002
Posts: 11,111
Likes: 598
From: Jackstandican
Default

Originally Posted by pdxmotorhead
I just did a head on a Honda, and it let just a little oil out then stopped, I think it was the MLS gasket heat cycling in to place. (Honda uses a gasket just like a LS MLS one.. )
No oil is shared between the block and head like an OHC motor per se. Leak would have to be from intake.
Reply
Old Apr 18, 2017 | 05:14 PM
  #11  
pdxmotorhead's Avatar
TECH Addict
5 Year Member
 
Joined: Oct 2016
Posts: 2,513
Likes: 480
From: PDX-OR-USA
Default

The oil gets to the push rods then drains back though,, thats where the Honda was leaking, it wasn't a pressure point it was in an area that allows the oil to drain back to the pan.. I don't think the head provides much "squish" at that point as its a long way relatively to the head bolts.

Do chevy heads still have the one bolt on the intake that deadheads in to the oil path that needs permatex on it? I know some used to it was like the driver front runner bolt..
Reply
Old Apr 18, 2017 | 05:47 PM
  #12  
SS RRR's Avatar
Village Troll
20 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Oct 2002
Posts: 11,111
Likes: 598
From: Jackstandican
Default

All intake fastening bolts onto the head tap into the oil valley, so technically it can leak from them if sealant is not applied to the threads, but is blatantly obvious when it happens.
Reply




All times are GMT -5. The time now is 03:36 AM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE