Generation IV Internal Engine 2005-2014 LS2 | LS3 | LS7 | L92 | LS9

Coolant won't circulate?

Thread Tools
 
Search this Thread
 
Old May 11, 2012 | 06:11 AM
  #1  
Forced_Induction's Avatar
Thread Starter
Staging Lane
 
Joined: May 2010
Posts: 55
Likes: 0
Default Coolant won't circulate?

I have a TSP 402 LS2 in a Mazda RX7.

Here's what happened:

My old radiator started to leak, so I bought a new one and installed it. Burped the system and went for a drive. Everything was fine until I got on the highway, one of the radiator mounts came loose yanking my lower radiator hose off the thermostat housing causing a big mess. I immediately shut the car off, pulled over and got it towed.

Got home, reinforced the mounts, refilled with coolant. Let it idle for a little while with the radiator cap off, topped off coolant and garaged the car and haven't touched it for about two weeks.

I took the car out last night. Let it warm up a little and took it down my street. Noticed my temps started getting really hot (230F). Pulled over, shut the car off, popped the hood and my radiator was ice cold to the touch, lower radiator hose was barely warm.

I figured I have a stuck closed thermostat. Went and bought a new one at Autozone. Put it in. Started the car up again and let it run some until it started getting really hot again. Shut it down and my radiator was still cold.


Am I missing something?
Reply
Old May 11, 2012 | 06:13 AM
  #2  
roninsonic's Avatar
TECH Enthusiast
10 Year Member
iTrader: (3)
 
Joined: Sep 2011
Posts: 584
Likes: 0
From: Mayport, FL
Default

Sounds like there might be a big-*** air bubble in the system.
Reply
Old May 11, 2012 | 07:25 AM
  #3  
Forced_Induction's Avatar
Thread Starter
Staging Lane
 
Joined: May 2010
Posts: 55
Likes: 0
Default

Hmm.. That's what I was thinking
Reply
Old May 11, 2012 | 07:37 AM
  #4  
SweetS10V8's Avatar
12 Second Club
iTrader: (4)
 
Joined: Jun 2004
Posts: 2,580
Likes: 3
From: Michigan
Default

I leave the coolant crossover ports open as I fill the engine, a massive amount of air comes out. Then when the coolant starts coming out for a second or two, I install the crossover.

Since the coolant temp sensor is in the head, an air pocket forms and itll read very hot. Id loosen the crossovers and start filling it with more water.
Reply
Old May 11, 2012 | 09:21 AM
  #5  
Forced_Induction's Avatar
Thread Starter
Staging Lane
 
Joined: May 2010
Posts: 55
Likes: 0
Default

Crossovers on the heads right?
Reply
Old May 11, 2012 | 01:00 PM
  #6  
SweetS10V8's Avatar
12 Second Club
iTrader: (4)
 
Joined: Jun 2004
Posts: 2,580
Likes: 3
From: Michigan
Default

Yeah, the 4 corners. Sometimes all 4 are interconnected, and some have a crossover on the front and two block offs on the rear.

Reply
Old May 11, 2012 | 11:56 PM
  #7  
427 zeo6's Avatar
On The Tree
 
Joined: Mar 2012
Posts: 131
Likes: 2
Default

Other possibility would be a big air pocket in lower radiator hose, I like to drill a 1/4" hole in my thermostats to allow air to vent through them when filling cooling system.
Reply
Old May 12, 2012 | 10:06 AM
  #8  
jay_lt4's Avatar
10 Second Club
iTrader: (4)
 
Joined: Oct 2006
Posts: 855
Likes: 0
From: wisconsin
Default

i have ran into this on several engine swaps with the rad at different height compared to the engine,, i take the top hose off the rad and fill coolant right into the hose to fill the engine full of coolant first. this has always worked for me
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 May 14, 2012 | 05:26 AM
  #9  
Forced_Induction's Avatar
Thread Starter
Staging Lane
 
Joined: May 2010
Posts: 55
Likes: 0
Default

You guys were right. It was just a big air pocket in the block. Cross over trick works well.
Reply
Old May 14, 2012 | 06:22 AM
  #10  
SweetS10V8's Avatar
12 Second Club
iTrader: (4)
 
Joined: Jun 2004
Posts: 2,580
Likes: 3
From: Michigan
Default

Good!
Reply




All times are GMT -5. The time now is 09:57 AM.

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