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

Overheating problem

Old May 8, 2011 | 12:32 PM
  #1  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default Overheating problem

A while back I bought a 1996 Formula that was in pretty rough shape and in non start condition. I recently got it all put together and have some issues. The mods in the car are comp engineering drag shocks, lca relocation brackets, heater hose mod, 3.42's, eBay headers and y pipe, ngk tr55 plugs, Msd wires, ls1 steering shaft, fuel line relocation, wire mod, ls1 front brakes, egr and air delete, hvac delete, power steering delete, low mount alternator relocation, ls1 lid coming soon and I have taken out plenty of weight. I have been trying to get the car from over heating but I have not been successful. I have gotten a new water pump, thermostat, radiator, hoses, fans, radiator cap, coolant and sensors. Before I turn it on I always flip the switch for the fans onto high and ill start her up. I let her sit there and wait to see of she will warm up but all I see is the needle dig in on the red side and the check gauges light comes on. After that happens I go check the motor and its not really too hot. I can even open the radiator and all I get is a lil pressure to pop out and noting more the water barely feels warm. When I touch the hoses while running they don't feel warm or anything. I switched the sensor in the water pump so that I could get the same reading to the computer and temp gauge. I hope this is enough info in the problem.

Thanx for any help
Reply
Old May 8, 2011 | 12:35 PM
  #2  
rich5368's Avatar
TECH Regular
iTrader: (2)
 
Joined: Apr 2010
Posts: 442
Likes: 0
From: Cheyenne, WY
Default

Could possibly be a faulty temp sending unit.
Reply
Old May 8, 2011 | 12:47 PM
  #3  
Big Al's Avatar
TECH Resident
iTrader: (1)
 
Joined: May 2005
Posts: 970
Likes: 1
Default

There are two temperature sending units, one for the PCM mounted on the water pump, the other for the gauge mounted in the driver's side head just under the header. How long does it run before the gauge shows overheating? (I don't understand : "I switched the sensor in the water pump so that I could get the same reading to the computer and temp gauge." What exactly did you do?

Al 95 Z28
Reply
Old May 8, 2011 | 12:49 PM
  #4  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default

I tried the stock one located in the driver side head twice and it would not send a temp, once I tried the mod which would send the temp to both the computer and temp gauge it finally started reading it. Idk if I should try leaving it on till I see signs of a real overheating problem but I just don't want to blow any head gaskets. I would believe that it should build up some pressure after running for a couple shouldn't it?
Reply
Old May 8, 2011 | 12:55 PM
  #5  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default

On ltxtech there was a thread on switchin the sensor on the water pump and the connector to the sensor would be wired up the green wire leading to the gauge as well as the two wires leading to the computer. This mod is meant to get the same reading to both computer and gauge in attempt to get rid of the crappy sensor in the head that never works right. I have two firebirds and neither one uses the head temp sensor for readings on temp gauge
Reply
Old May 8, 2011 | 01:04 PM
  #6  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default

http://ltxtech.com/forums/showthread...ght=temp+gauge

This is where I got the mod from
Reply
Old May 8, 2011 | 01:27 PM
  #7  
Big Al's Avatar
TECH Resident
iTrader: (1)
 
Joined: May 2005
Posts: 970
Likes: 1
Default

Originally Posted by Xposure
I'm new to this so I did not now about that mod. But: If you run out of water, like bust a hose or something, the water pump will not get hot. Well it may but it would be too late to do any good. Chevrolet put the gauge sensor in the head for a reason, because it gets hot quick if the water is gone. That's why they moved it from the intake manifold many years ago. If they could have saved 10 cents on a sensor they would have.

Just my opinion.....

Al 95 Z28
Reply
Old May 8, 2011 | 01:34 PM
  #8  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default

The reason I did that mod was because out of the sensor that came on the car, one from the junk yard and a new one from autozone along wit three different connectors, I could not get the temp gauge to move until I did this mod
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 May 8, 2011 | 05:19 PM
  #9  
96azz28's Avatar
On The Tree
 
Joined: Dec 2010
Posts: 166
Likes: 0
Default

Possibly the water pump drive shaft coupler went out
Reply
Old May 8, 2011 | 05:33 PM
  #10  
GM PHASST's Avatar
On The Tree
 
Joined: Apr 2010
Posts: 162
Likes: 0
From: Philly
Default

U should try and get the correct temp sending unit from the dealer. Local stores like autozone and pepboys will sell u a engine coolant temp sensor which goes into the waterpump instead of a temp sending unit which goes in the head.
And u r bleeding all of the air out thru the thermostat neck rite?
Reply
Old May 8, 2011 | 07:01 PM
  #11  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default

When i installed the new water pump i filled the block completely with long life coolant from az and i let it sit for thirty like that to make sure it did not go down anymore. I then put the new 180 degree thermostat also from az and then filled the radiator up with the one bleeder screw open. I have deleted the hvac lines on the water pump and simply put a plug on them so i only have one bleeder screw. I do also have the steam pipe connected straight to the radiator in the opening right below the one that goes to the overflow tank. I will probably try the right sending unit but i still dont think that will solve the problem of me being able to run my car for five minutes and not build up any pressure in the system. i can go and pop open the cap on the radiator right after and nothing major like gushing coolant will happen like on my other firebird.
Reply
Old May 8, 2011 | 07:02 PM
  #12  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default

How would i check the water pump shaft coupler?
Reply
Old May 8, 2011 | 09:54 PM
  #13  
96azz28's Avatar
On The Tree
 
Joined: Dec 2010
Posts: 166
Likes: 0
Default

Un Bolt the water pump and behind you'll see the coupler mine was spinning freely, the inside was grazed out
Reply
Old May 8, 2011 | 10:02 PM
  #14  
Xposure's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2010
Posts: 148
Likes: 0
Default

Well I tried spinning it and it had a lil slack but never spun freely on either the motor part of the water pump part
Reply


Thread Tools
Search this Thread

All times are GMT -5. The time now is 08:27 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 | 2026-06-04 18:13:20


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