Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

Cooling Issues

Thread Tools
 
Search this Thread
 
Old Apr 16, 2013 | 06:23 PM
  #1  
dirtbag's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Jul 2005
Posts: 218
Likes: 1
From: St. Louis, MO
Default Cooling Issues

I've had cooling issues with my car for a while now. Runs about 210-215 degrees in 70-80 degree weather. After running through the gears, this will rise to 215-220 degrees temporarily, then return to 210-215 degrees. FYI - 347ci heads and cam car, see signature for setup.

What has been already replaced/addressed:
- Swapped in a new LT1 radiator in place of the stock LS1 radiator.
- New LS1 water pump.
- Recently tuned with the new motor so excessive timing is not an issue, as well as fan "on" temperatures.
- Existing stock LS1 thermostat. (Roughly 6k miles on this thermostat FYI)
- No air in the system, bled the extra air out and use a 50/50 mix of Dexcool coolant.
- Not low on coolant in the radiator or overflow reservoir.

What I think could be the culprit:
- SSRA blocking radiator for proper cooling. Temperatures are high whether idling at a stoplight or cruising at highway speeds.
- Thermostat spring is shot from running hot previously (highest was 230 degrees).
- Dashboard temperature gauge is simply not accurate and it's really not running hot.

I know LS1's typically run a little hotter than a traditional SBC, but 210 degrees seems too high. Also, in warmer weather with hotter coolant temperatures, the car definitely feels down on power. I really want to fix this cooling problem.

Thoughts? Thanks.
Reply
Old Apr 16, 2013 | 08:52 PM
  #2  
Paul Bell's Avatar
That's MISTER MODERATOR
20 Year Member
Photogenic
Liked
Loved
iTrader: (9)
 
Joined: Nov 2005
Posts: 7,616
Likes: 65
From: NYC
Default

Is that annoying lip air dam that drags when you turn into driveways still in place?

Removing makes the temps go up & up & up on the highway.
Reply
Old Apr 16, 2013 | 09:57 PM
  #3  
Marc3.4V6's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Aug 2005
Posts: 1,080
Likes: 0
From: San Diego
Default

You need a scanner of some kind to read from the computer, the dashboard gauge isn't accurate, you could be running hotter, or colder than you think. Although if it moves past 210 it's likely getting a little hotter than 210, you're just in the dark if you rely on the needle in my opinion.
Reply
Old Apr 16, 2013 | 10:56 PM
  #4  
sjsingle1's Avatar
TECH Senior Member
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (1)
 
Joined: Feb 2010
Posts: 6,761
Likes: 292
From: Fort Worth TX
Default

you could always try a 160 stat........
Reply
Old Apr 16, 2013 | 11:14 PM
  #5  
LS6427's Avatar
Banned
iTrader: (2)
 
Joined: May 2008
Posts: 11,289
Likes: 13
From: South Florida
Default

Listen here dirtbag.....lol.....had to say it.......

Anyway.....yes, 215 is too hot in my opinion. it would drive me insane if my temps were like that. my 427ci always ran around 195*F in hot Florida weather. There's something wrong. A very common thing for people to do when swapping a radiator is they do not get the fan housing back on perfectly snug up against the new radiator. Make sure the fan shroud is tight up against the radiator, and that the shroud is hanging on all 4 hooks. If the shroud is bent up or damaged or there's a gap in the shroud between the radiator and shroud......you're doomed, you will run hot. That causes the air from the fans to be wasted.

Lower front air dam needs to be perfect, no damage. This is mainly for cooling while cruising on the highway.
Fans do all the cooling, or almost all of it while at low speeds and stop and go driving.

And personally, I'd run a half jug of anti-freeze, just a HALF jug....the rest water.

Maybe change the t-stat again....lots of times new t-stats are just duds.....

The fans......make sure they are BOTH coming on at the same time and that BOTH are running in both LOW and HIGH settings. Next time your temps read 215, pull over and with your hand make sure BOTH fans are on. Fans on our cars always run together and go off together.
.....I would buy a laser temp gauge to check the temps with.....don't rely on the gauge in the cluster.......Use the laser and aim it right at the drivers side head right next to the temp sensor to get the best reading.


.
Reply
Old Apr 16, 2013 | 11:21 PM
  #6  
ZouMechE's Avatar
Staging Lane
iTrader: (1)
 
Joined: Jan 2013
Posts: 63
Likes: 0
From: Columbia, MO (Mizzou)
Default

Originally Posted by sjsingle1
you could always try a 160 stat........
Would not make a difference.
Reply
Old Apr 17, 2013 | 12:16 PM
  #7  
spy2520's Avatar
12 Second Club
20 Year Member
Photogenic
Photoriffic
iTrader: (3)
 
Joined: Feb 2005
Posts: 3,513
Likes: 1
From: Waldorf, MD
Default

What temp are the fans set to come on at?
Reply
Old Apr 17, 2013 | 12:30 PM
  #8  
jimmyblue's Avatar
Moderator
iTrader: (11)
 
Joined: Mar 2002
Posts: 12,604
Likes: 7
From: East Central Florida
Default

Thermostat makes zero difference here.

Fan settings must be fixed, they simply suck from
factory.

Then, go blow out the condenser and the new radiator,
reverse flow, and see how much debris you get.

Ducted cold air systems do shroud the condenser and
could be adding to the situation. That should be easy
enough to test.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

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

 Pouria Savadkouei
story-2

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

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

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

 Verdad Gallardo
story-5

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

 Pouria Savadkouei
story-6

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

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old Apr 17, 2013 | 01:37 PM
  #9  
dirtbag's Avatar
Thread Starter
Launching!
iTrader: (2)
 
Joined: Jul 2005
Posts: 218
Likes: 1
From: St. Louis, MO
Default

Originally Posted by LS6427
Listen here dirtbag.....lol.....had to say it.......

Anyway.....yes, 215 is too hot in my opinion. it would drive me insane if my temps were like that. my 427ci always ran around 195*F in hot Florida weather. There's something wrong. A very common thing for people to do when swapping a radiator is they do not get the fan housing back on perfectly snug up against the new radiator. Make sure the fan shroud is tight up against the radiator, and that the shroud is hanging on all 4 hooks. If the shroud is bent up or damaged or there's a gap in the shroud between the radiator and shroud......you're doomed, you will run hot. That causes the air from the fans to be wasted.

Fans are snugged up to radiator. No shroud damage. No problem here.

Lower front air dam needs to be perfect, no damage. This is mainly for cooling while cruising on the highway.
Fans do all the cooling, or almost all of it while at low speeds and stop and go driving.

Lower front air dam is in good condition. No problem here.

And personally, I'd run a half jug of anti-freeze, just a HALF jug....the rest water.

Will try this.

Maybe change the t-stat again....lots of times new t-stats are just duds.....

I'm putting a 160 degree thermostat in for the heck if it. My tuner has set the fans for a 160 stat so it should no issue to make the switch over.

The fans......make sure they are BOTH coming on at the same time and that BOTH are running in both LOW and HIGH settings. Next time your temps read 215, pull over and with your hand make sure BOTH fans are on. Fans on our cars always run together and go off together.
.....I would buy a laser temp gauge to check the temps with.....don't rely on the gauge in the cluster.......Use the laser and aim it right at the drivers side head right next to the temp sensor to get the best reading.

Definitely gonna try the laser temp gauge. Both fans do come on correctly.

.
Answers are in the quote. Thanks for the responses guys. I'll respond with the results as soon as I can.
Reply




All times are GMT -5. The time now is 07:56 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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