General Maintenance & Repairs Leaks | Squeaks | Clunks | Rattles | Grinds
Sponsored by:
Sponsored by: CARiD

Switch back to Regular oil or what

Thread Tools
 
Search this Thread
 
Old Jan 1, 2012 | 01:57 PM
  #1  
Red97LT1's Avatar
Thread Starter
TECH Apprentice
iTrader: (8)
 
Joined: Dec 2006
Posts: 381
Likes: 0
From: Western North Carolina
Default Switch back to Regular oil or what

Hey guys,
I am getting a half dollar size leak under my car now everyday. I still have good pressure and I keep an eye on the oil level. Looks like a rear main seal to me.I also have been told it could be the Lower intake manifold gaskets.I'm going to get under there and clean it up and try to see where the leak is coming from.

I have always use Mobil 1 10w-30 Synthetic but was wondering if I should go to a thicker weight in a regular or stick with the Syn and use a thicker weight.Not sure if it would help at all with the leak or not.Buddy of mine just said that Synthetics tend to leak more if gaskets,seals ,etc are bad.

Last edited by Red97LT1; Jan 1, 2012 at 02:02 PM.
Reply
Old Jan 1, 2012 | 03:58 PM
  #2  
nascarnate326's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Sep 2009
Posts: 1,574
Likes: 1
From: Michigan
Default

I switched form M1 to regular oil to "fix" a leak I have, it made it much worse.

You will just have to try and see what happens.
Reply
Old Jan 1, 2012 | 06:04 PM
  #3  
Red97LT1's Avatar
Thread Starter
TECH Apprentice
iTrader: (8)
 
Joined: Dec 2006
Posts: 381
Likes: 0
From: Western North Carolina
Default

Originally Posted by nascarnate326
I switched form M1 to regular oil to "fix" a leak I have, it made it much worse.

You will just have to try and see what happens.
Thanks for the info. I'm going to use some M1 5W-30 and see what happens.
Reply
Old Jan 1, 2012 | 10:17 PM
  #4  
jaxcam02's Avatar
TECH Fanatic
15 Year Member
iTrader: (1)
 
Joined: Jan 2010
Posts: 1,642
Likes: 19
From: Jacksonville, Fl
Default

Originally Posted by Red97LT1
Hey guys,
I am getting a half dollar size leak under my car now everyday. I still have good pressure and I keep an eye on the oil level. Looks like a rear main seal to me.I also have been told it could be the Lower intake manifold gaskets.I'm going to get under there and clean it up and try to see where the leak is coming from.

I have always use Mobil 1 10w-30 Synthetic but was wondering if I should go to a thicker weight in a regular or stick with the Syn and use a thicker weight.Not sure if it would help at all with the leak or not.Buddy of mine just said that Synthetics tend to leak more if gaskets,seals ,etc are bad.
What I have heard is that a synthetic oil will swell the size of the gaskets due to the detergents and help "hydrate" the gaskets. Once you go synthetic you dont want to go back to conventional or semi synthetics because your gaskets will shrink and crack thus endusing a leak or making any leak worse. I switched from synthetic to conventional on my old 3.8l and it just made the leaks worse. If I am wrong someone correct me but from what I have read and heard you never want to go back and fourth.
Reply
Old Jan 1, 2012 | 11:41 PM
  #5  
LS1121's Avatar
TECH Addict
iTrader: (17)
 
Joined: Aug 2009
Posts: 2,054
Likes: 12
From: Charlotte NC
Default

The POS PCV we have on our cars rots away and can cause what looks like an oil leak. Check the rear of the driver side valve cover for oil and check the valve cover also. That is what caused me to FIX my PCV system.
Reply
Old Jan 2, 2012 | 03:36 AM
  #6  
Crimsonnaire's Avatar
TECH Regular
15 Year Member
iTrader: (1)
 
Joined: Jan 2008
Posts: 483
Likes: 1
Default

Also don't forget the oil pan gasket. A leak from this gasket will yield an identical appearance to that of a rear main seal leak. If you can't isolate it from the outside, take it to a shop that offers free initial inspections and have them remove the starter to see if there's oil spewed around the inner surface of the transmission housing. If so, it's the rear main.

Synthetic oil is more slick, thus creeping through crevices quicker. If your leak is already at that severity, you most probably won't reap any benefits from the additives in the synthetic oil. The leak may only worsen. At such a point, the only effective thing is either replacing the faulty part or stop leak addtives which you do not want if you intend to give the engine longevity.

Last edited by Crimsonnaire; Jan 2, 2012 at 03:45 AM.
Reply
Old Jan 5, 2012 | 09:51 PM
  #7  
LSPoncho's Avatar
Teching In
 
Joined: Jan 2010
Posts: 25
Likes: 0
From: California
Default

Before I swapped in the LS, my LT did the same thing. My leak was from the rear valley seal on the intake manifold. Apparently, GM did not put high temp sealer there and the heat from the EGR line melts the sealer. I would avoid trying to "fix" oil leaks with different viscosity oils or types of oil. Any change in the leak would be temporary or coincidence.
Reply
Old Jan 6, 2012 | 01:19 AM
  #8  
xhifer's Avatar
Staging Lane
 
Joined: Aug 2011
Posts: 69
Likes: 0
Default

I used valvoline max life 10w30 and it helped minimized my leak significantly on my old 190k z28.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

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

 Verdad Gallardo
story-1

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

 Pouria Savadkouei
story-2

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

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

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

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo




All times are GMT -5. The time now is 04:24 AM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE