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

over heating problem

Old Jun 10, 2009 | 09:20 AM
  #1  
ALEXZ28's Avatar
Thread Starter
Launching!
 
Joined: Feb 2009
Posts: 201
Likes: 0
Default over heating problem

after putting my engine back in the car for some reason now im having a over heating problem, at first fas were not working and i wired them to ign. so fans work, water pump is working as well. car is over heating while sitting still if i start driving temp goes down. any idea?
Reply
Old Jun 10, 2009 | 09:24 AM
  #2  
dkishton1486's Avatar
On The Tree
 
Joined: Mar 2006
Posts: 121
Likes: 0
From: Boardman, Ohio
Default

What thermostat are you running?
Reply
Old Jun 10, 2009 | 10:22 AM
  #3  
ALEXZ28's Avatar
Thread Starter
Launching!
 
Joined: Feb 2009
Posts: 201
Likes: 0
Default

Originally Posted by dkishton1486
what thermostat are you running?
stock, i think they set at 190- or 200. Might go buy a 160 today and try it but b4 i spend the money and it dont fix wanted to see if anyone here had this problem.
Reply
Old Jun 10, 2009 | 10:29 AM
  #4  
D41LYDRVN's Avatar
Registered User
 
Joined: Jun 2009
Posts: 4
Likes: 0
From: Ft. Rucker / Tuscaloosa, Alabama
Default

I had the SAME problem.. so I put in a 160 and it is MUCH more resistant to heating up when I'm in traffic. It runs a lot cooler driving around town, just up off the 160 mark on the gauge. I mean, its still going to heat up some if you're just sitting there, but imo its a must. do it
Reply
Old Jun 10, 2009 | 11:28 AM
  #5  
ALEXZ28's Avatar
Thread Starter
Launching!
 
Joined: Feb 2009
Posts: 201
Likes: 0
Default

yea got alot to do with the water pump, been thinking about getting me a eletric water pump. i havent tried to change the thermostat yet, prob do it today. hoping thats the problem.
Reply
Old Jun 10, 2009 | 12:01 PM
  #6  
ss.slp.ls1's Avatar
TECH Senior Member
15 Year Member
iTrader: (36)
 
Joined: Jan 2008
Posts: 8,184
Likes: 28
From: Orange County, CA
Default

Sounds like you have air in the system. Did you bleed it properly?
Why the fans weren't coming on is a different issue...
Also a 160* would be most beneficial with reprogrammed fan settings.
Reply
Old Jun 10, 2009 | 12:25 PM
  #7  
ALEXZ28's Avatar
Thread Starter
Launching!
 
Joined: Feb 2009
Posts: 201
Likes: 0
Default

yea i tryed to bleed the system, im sure i did it right but still over heating, not sure why the fans werent working, they were fine til i dropped the motor. im going to try to bleed it again and change to a 160, dont think thats going to work but maybe ill get lucky. the temp has been getting around 210, sometimes stays there and times it will get hotter and water will start coming out the spare tank
Reply
Old Jun 10, 2009 | 12:40 PM
  #8  
ss.slp.ls1's Avatar
TECH Senior Member
15 Year Member
iTrader: (36)
 
Joined: Jan 2008
Posts: 8,184
Likes: 28
From: Orange County, CA
Default

Originally Posted by ALEXZ28
yea i tryed to bleed the system, im sure i did it right but still over heating, not sure why the fans werent working, they were fine til i dropped the motor. im going to try to bleed it again and change to a 160, dont think thats going to work but maybe ill get lucky. the temp has been getting around 210, sometimes stays there and times it will get hotter and water will start coming out the spare tank
Huh, you do know that ~220 degrees is normal operating temperature for a LT1 right?

As the stock programming is set, the fans don't come on until 226*/235* for the low/high speed fans.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

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

 Verdad Gallardo
story-1

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-2

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-3

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-4

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

 Verdad Gallardo
story-5

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-6

10 Camaros You Should Never Buy

 
story-7

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
story-8

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

 Brett Foote
story-9

10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

 Verdad Gallardo
Old Jun 10, 2009 | 03:56 PM
  #9  
Niteninja's Avatar
Staging Lane
20 Year Member
 
Joined: Feb 2005
Posts: 51
Likes: 0
Default

Have you checked the cooling fan relay's? That was my problem.
Reply
Old Jun 10, 2009 | 04:01 PM
  #10  
infinitebird's Avatar
TECH Veteran
20 Year Member
Liked
iTrader: (11)
 
Joined: Jul 2004
Posts: 4,280
Likes: 51
From: Denver, CO
Default

Originally Posted by ss.slp.ls1
Sounds like you have air in the system. Did you bleed it properly?
I don't think its anything to do with that since he says it cools down at speed. If there was air in the system it would be getting hot regardless.

Though, based on his subsequent reply I think he is just confused about what normal temp is.

210-220 isn't overheating, though it is a lot hotter than many people like to run their cars. 160 thermo and reprogrammed fans or fan switch help with that.
Reply
Old Jun 10, 2009 | 04:59 PM
  #11  
ALEXZ28's Avatar
Thread Starter
Launching!
 
Joined: Feb 2009
Posts: 201
Likes: 0
Default

Fans weren't working I hooked them up to the igniton so now they stay on while the key is turned, why does it steem when I park, I can hear it steeming and water starts boiling and comes out the tank.
Reply
Old Jun 10, 2009 | 05:04 PM
  #12  
ss.slp.ls1's Avatar
TECH Senior Member
15 Year Member
iTrader: (36)
 
Joined: Jan 2008
Posts: 8,184
Likes: 28
From: Orange County, CA
Default

Originally Posted by ALEXZ28
Fans weren't working I hooked them up to the igniton so now they stay on while the key is turned, why does it steem when I park, I can hear it steeming and water starts boiling and comes out the tank.
If after you let the car reach operating temp and then you shut it off and it boils out the overflow tank, you are loosing pressure somewhere...
I had that happen once and I had a leaky hose and a bad radiator cap.
I would pick up a pressure tester and look to see if it holds pressure.
Reply
Old Jun 11, 2009 | 07:05 AM
  #13  
ALEXZ28's Avatar
Thread Starter
Launching!
 
Joined: Feb 2009
Posts: 201
Likes: 0
Default

last night went for a drive, as the temp got to 225 and i shut the car off, heard in the front of the car boiling water. fans were working also. im thinking about taking it to get flushed out good see what happens.
Reply
Old Jun 11, 2009 | 09:43 AM
  #14  
trippinholyman's Avatar
Launching!
 
Joined: Feb 2009
Posts: 280
Likes: 0
From: bodymore
Default

any work done where the cooling system was drained / filled ? when i first got the car i had a problem with it overheating. the ****** i bought it from at the lot didn't know that you have to bleed the cooling system. theres two screws you turn and run the car until all the air bubbles come out. what it is is air pockets get in the cooling system and cause it to cool unevenly, so parts are too hot and others aren't. the air pushes up and the coolant overflows.
Reply
Old Jun 11, 2009 | 11:10 AM
  #15  
lt1phantom791's Avatar
Teching In
 
Joined: Dec 2008
Posts: 39
Likes: 0
Default

I'm going to guess that your car overheats at temps close to 220, that's not normal, your radiatorcap is the the culprit for this, my lt1 gets to 230 on a hot day withought boiling over.
Reply
Old Jun 11, 2009 | 11:40 AM
  #16  
ss.slp.ls1's Avatar
TECH Senior Member
15 Year Member
iTrader: (36)
 
Joined: Jan 2008
Posts: 8,184
Likes: 28
From: Orange County, CA
Default

Originally Posted by ALEXZ28
last night went for a drive, as the temp got to 225 and i shut the car off, heard in the front of the car boiling water. fans were working also. im thinking about taking it to get flushed out good see what happens.
You don't have to shut your car off just because it got to 225...
Flushing the system won't hurt, but I would get a pressure tester first, see if it holding pressure.

Originally Posted by lt1phantom791
I'm going to guess that your car overheats at temps close to 220, that's not normal, your radiatorcap is the the culprit for this, my lt1 gets to 230 on a hot day withought boiling over.
That's a good idea, a new cap is cheap and its a quick test. I had the same problem a few years back.
Reply
Old Jun 11, 2009 | 04:17 PM
  #17  
lt1phantom791's Avatar
Teching In
 
Joined: Dec 2008
Posts: 39
Likes: 0
Default

Nothing else would cause your coolant to boil up at 220, its your radiator cap, don't waste time and money trying different things, if your caps fine witch its not going to be, check your heater hoses for cracks or leaks, this is a pressure issue.

Last edited by lt1phantom791; Jun 11, 2009 at 04:25 PM.
Reply
Old Jun 11, 2009 | 04:28 PM
  #18  
ss.slp.ls1's Avatar
TECH Senior Member
15 Year Member
iTrader: (36)
 
Joined: Jan 2008
Posts: 8,184
Likes: 28
From: Orange County, CA
Default

Originally Posted by lt1phantom791
Nothing else would cause your coolant to boil up at 220, its your radiator cap, don't waste time and money trying different things, if your caps fine witch its not going to be, check your heater hoses for cracks or leaks, this is a pressure issue.
Agreed.
Reply
Old Jun 11, 2009 | 04:39 PM
  #19  
T.J.C.'s Avatar
Teching In
 
Joined: May 2009
Posts: 2
Likes: 0
From: Milwaukee, WI
Default

I currently have the exact same thing going on, with my 97 T/A... so far changed T-stat (180), radiator cap, upper and lower radiator hoses, and temp sending unit. But I did not check the heater hoses... did not seem to be damaged @ all, but I did not look closely enough I guess. I tried to test the pressure of radiator, but as I started pumping air, there was no preesure reading. The Oil looks fine, no white smoke out the exhaust, so I am ruling out a blown gasket for now. The water pump looks fairly new just eyeballin it. When I bled the system, I heard air hissing out the bleed valves while filling the tank, but no water coming out. The only thing left to do I guess is flush the system. I just picked it up a few weeks ago, 160k on the clock...drives very strong. This is getting too be real frustrating for me lol as I am ready to drive it w/o worrying ya know?
Reply
Old Jun 11, 2009 | 04:41 PM
  #20  
ss.slp.ls1's Avatar
TECH Senior Member
15 Year Member
iTrader: (36)
 
Joined: Jan 2008
Posts: 8,184
Likes: 28
From: Orange County, CA
Default

Originally Posted by T.J.C.
I currently have the exact same thing going on, with my 97 T/A... so far changed T-stat (180), radiator cap, upper and lower radiator hoses, and temp sending unit. But I did not check the heater hoses... did not seem to be damaged @ all, but I did not look closely enough I guess. I tried to test the pressure of radiator, but as I started pumping air, there was no preesure reading. The Oil looks fine, no white smoke out the exhaust, so I am ruling out a blown gasket for now. The water pump looks fairly new just eyeballin it. When I bled the system, I heard air hissing out the bleed valves while filling the tank, but no water coming out. The only thing left to do I guess is flush the system. I just picked it up a few weeks ago, 160k on the clock...drives very strong. This is getting too be real frustrating for me lol as I am ready to drive it w/o worrying ya know?
I would check the heater hoses, don't forget to chect the little hose that goes to the steam pipe (or routes to your TB, and then from the TB to the steam pipe if you haven't done the TB bypass yet). Also check the little hose that connects to your overflow tank.
Reply

Thread Tools
Search this Thread

All times are GMT -5. The time now is 05:14 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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
story-9
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

Slideshow: The 7.0-liter LS7 was designed for absolute cutting-edge performance.

By Verdad Gallardo | 2026-01-07 18:36:00


VIEW MORE