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

Possible blown head gasket

Thread Tools
 
Search this Thread
 
Old Mar 6, 2013 | 11:48 PM
  #1  
rg501's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Oct 2008
Posts: 227
Likes: 0
From: michigan
Default Possible blown head gasket

Days ago i had a coolant flush done, new water pump, new thermostat, heater core flush and bled the system. Turned the car on, temp needle went to 260 within 2 minutes of idling. Turned car off, popped the hood and touched the top of the manifold. it was still cool. thought it might be the temp sensor, shop said temp sensor was fine. Went 3 days without overheating and now on the 4th day, it overheated. sometimes when you come to a stop sign and are just about to stop, the car feels like its misfireing alittle; kind of like a slight chugging. low coolant light is constantly on, however, coolant is full. fans are wired to a manual fan switch so they're on all the time. im taking it to another shop on friday and they're going to do a compression test and a chemical test to see if coolant leaked into the exhaust (i think thats what they ment).

whats the deal?
Reply
Old Mar 9, 2013 | 10:43 AM
  #2  
Mike.'s Avatar
Staging Lane
iTrader: (1)
 
Joined: Jun 2012
Posts: 72
Likes: 0
From: Jacksonville, Fl
Default

Could be something as simple as air in the coolant system. It sounds like you had this done at a shop? Low coolant light sounds like this going bad: http://shbox.com/1/low_coolant.jpg

Have you noticed any loss of coolant? Take the oil cap off and see if it looks like a chocolate milkshake?

Compression test wouldn't hurt if it puts your mind at ease though.
Reply
Old Mar 10, 2013 | 02:45 PM
  #3  
great421's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Feb 2006
Posts: 1,170
Likes: 2
Default

Open both coolant bleeders when vehicle is warm and make sure the system is free of air pockets first.
Reply
Old Mar 10, 2013 | 09:24 PM
  #4  
rg501's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Oct 2008
Posts: 227
Likes: 0
From: michigan
Default

well she passed a compression test. i'll have to check the coolant level sensor once i get it back tmrw. and yes, its at a shop right now. i looked at the oil cap, no milkshake there.
Reply
Old Mar 10, 2013 | 10:30 PM
  #5  
Zlow28's Avatar
TECH Addict
iTrader: (11)
 
Joined: Apr 2010
Posts: 2,080
Likes: 1
Default

bleed the coolant until you tire yourself, then do it once more. After that, do it one last time the next day.
Reply
Old Mar 11, 2013 | 05:53 AM
  #6  
KFtransam's Avatar
Launching!
 
Joined: Apr 2012
Posts: 233
Likes: 0
From: Crown point, IN
Default

If need be, raise the nose of the car up while bleeding. So happens that the heater core is the highest point on these cars and is notorious for trapping air
Reply
Old Mar 12, 2013 | 08:59 PM
  #7  
rg501's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Oct 2008
Posts: 227
Likes: 0
From: michigan
Default

Originally Posted by KFtransam
If need be, raise the nose of the car up while bleeding. So happens that the heater core is the highest point on these cars and is notorious for trapping air
makes sense, as the air would rise to the highest point.

but I did get the car back and there was apparently a very small crack in the lower radiator hose. replaced that and it's been fine for the past few days. thinking about bleeding it once more just to be safe.
Reply
Old Mar 12, 2013 | 10:47 PM
  #8  
Numba20's Avatar
TECH Regular
iTrader: (1)
 
Joined: Nov 2010
Posts: 459
Likes: 0
From: Kingston, TN
Default

Coolant lights are notorious for being stuck on. Head gaskets are no fun to replace, try everything else before hand. Also passing a compression test would be a chance of ruling out a crack in the head, but may want to consider it. If you end up replacing the head gaskets, might want to take the heads to a machine shop and have the pressure tested. (might as well while they are out, because once u get the thing back together, u sure don't wanna turn around and have to take it back apart!) A good indicator would be to jack the car so the the oil drain plug is at the farthest point down, and unscrew it just a tad to let it dribble, if you have coolant coming out (if there is any in there it will bc it's heavier than the oil and always sinks to the bottom) then there is a fat chance one or both heads have a crack, usually in the valve area, but hey it's a good excuse for a port job!!! Lol good luck!
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

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

 Pouria Savadkouei
story-1

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

 Verdad Gallardo
story-2

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-3

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-4

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-5

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

 Verdad Gallardo
story-6

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-7

10 Camaros You Should Never Buy

 
story-8

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
story-9

Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

 Brett Foote
Old Mar 13, 2013 | 09:41 PM
  #9  
rg501's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Oct 2008
Posts: 227
Likes: 0
From: michigan
Default

is there any way of making the coolant light turn off? whenever i have dash lights on like the SES or low coolant light, it makes me feel like im driving a piece of junk lol..
Reply
Old Mar 13, 2013 | 11:31 PM
  #10  
97z28K&N's Avatar
Staging Lane
 
Joined: Dec 2012
Posts: 55
Likes: 0
Default

unplug the coolant sensor and it will shut the light off.
Reply
Old Mar 14, 2013 | 12:47 AM
  #11  
1hotlt1's Avatar
Staging Lane
iTrader: (1)
 
Joined: Aug 2010
Posts: 78
Likes: 0
From: san lorenzo,ca
Default

Double check the thermostat. It happend to me once the sold me a bad one.
Reply
Old Mar 14, 2013 | 07:43 AM
  #12  
KFtransam's Avatar
Launching!
 
Joined: Apr 2012
Posts: 233
Likes: 0
From: Crown point, IN
Default

Originally Posted by 97z28K&N
unplug the coolant sensor and it will shut the light off.
Yep, do this.. Mines been unplugged for about a year now
Reply




All times are GMT -5. The time now is 04:06 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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
story-9
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

The world was a better place when it was still around.

By Brett Foote | 2026-01-23 09:20:37


VIEW MORE