Sbc 4.3 v6 head gasket leak? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans Advertise
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 09-05-2019, 11:28 AM
Registered User
 
Join Date: Jun 2014
Posts: 135
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sbc 4.3 v6 head gasket leak?

Hi

I check heads and did head gasket job and other seals about 15k ago. Car was first doing bubbles after shut off and just before i remove heads there was bubbling in radiator when cap was off.


Now in last month ive noticed that there is coolant loss in reservoir. I did marks on reservoir coolant level and it has dropped two times about inch. I have hot and cold marks.


I did coolant system pressure test today. System holded pressure 10minutes, then i released pressure. No leaks and no coolant smell.


Exhaust smoke is colorless, no white. Oil is good.


I started engine without cap when it was allmost cold. Near thermostat opening there was couple time bubbles. Bubble was big and lazy, about 1/4 size of radiator neck. So couple that size bubble in two minute. After that coolant was overflowing outside radiator (because engine was warm enough) so i had to close cap.



Is there again problem in head/head gasket? Car is on daily use and winter is coming, so i must do job soon if there is problem.


Is there anything else tests to do? I must check spark plug color, how about pressurising system and spark plugs off?


Engine runs very well and temp is steady.


Help me!



Engine is 1992 chevrolet 4.3 v6 tbi.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-05-2019, 12:41 PM
Registered User
 
Join Date: Apr 2007
Posts: 12,294
Wiki Edits: 0

Thanks: 167
Thanked 1,103 Times in 880 Posts
Check the reservoir for a crack that leaks coolant.

Bogie
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-05-2019, 01:00 PM
Registered User
 
Join Date: Jun 2014
Posts: 135
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
No cranks seen and reservoir is dry. That amount of fluid usually leaves moist
Reply With Quote Quick reply to this message
 
  #4 (permalink)  
Old 09-06-2019, 05:06 AM
Registered User
 
Join Date: Jan 2012
Location: Grand Rapids, MI
Posts: 1,921
Wiki Edits: 0

Thanks: 213
Thanked 394 Times in 321 Posts
Check the hose going from radiator to overflow and the neck of the radiator that connects to the overflow hose.

You can check the neck and hose by plugging the end that goes into the overflow with a bolt then pressurize the system.

The bubbles your describing is usually bad lower fins or a lower hose allowing air in. Things expand when they get hot. These include hoses.


Also do not dismiss the cap. I have solved several mystery coolant leaks(northstars that they think is instantly a bad head gasket) with a new cap and few hoses.

Caps are a maintenance item. They can allow coolant to leak past that paper thin gasket overtime.

You may not see coolant on the ground as it will evaporate especially with radiatiors that have metal sides. Now there may be some stains. But if you dont wipe down or degrease the sides these can easily be overlooked.



I would replace the overflow hose, clamps, and cap. Preventive maintance, cheap, and may fix your issue.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 08:25 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.