new cooling issue - Team Camaro Tech
Heating & Cooling Heating, cooling and air conditioning Sponsored by:Cold-Case Aluminum Radiators

 2Likes
  • 1 Post By 69-Pace
  • 1 Post By ilikeike
 
LinkBack Thread Tools Display Modes
post #1 of 13 (permalink) Old Apr 8th, 19, 05:07 PM Thread Starter
Tech Team
 
Join Date: Aug 2018
Posts: 31
new cooling issue

I've had my 68 camaro since last august. It has the four gauge cluster on the console. SBC 400 (late 70s) and a TH350 automatic trans.

The temp gauge had always registered one small notch past the first large notch despite weather or distance driven. I guessed that was an inaccurate reading as it would likely be only about 120*. In Oct, after getting it back from the shop, the gauge started registering different temps. It will show temps raising pretty steadily on idle, but will go up to the yellow line (about 211*?) and then fall back a few notches and go back up to the yellow line while driving.



I was concerned that the t-stat wasn't opening, so I pulled out the pretty old 160* and put in a new (tested) 180*. intake was dry so I think the 160 t-stat had failed. Afterwards, I let the engine idle for about 5 minutes and temps sat at the beginning of the yellow line.
when I took it out for a drive, the temp would go back to the yellow line with acceleration and drop down to about 190* or so when I was idle at a light or off the accelerator. Air temp. was about 70*.



When I checked radiator coolant, it was low, so I added 50/50 coolant about a week ago. Yesterday, the coolant looked about 4 inches lower than my previous fill line (checked on cold engine). I think I'd only driven about 2-3 very short trips in that time. Radiator is unknown age, but a stock type with stamped reservoirs. I have not seen any puking out the overflow. The rad. cap is an unknown lbs rating. Am I checking this wrong? The level of coolant shouldn't change that much should it?



I have checked the temps in the engine bay with a laser a few times. block in front and on side by temp sender were at about 210*, top radiator hose was about 193*. Lower hose was around 160* something. It appears that the temp. gauge is reading pretty close.



Am I getting normal operating temps? Seeing the temp needle go in to the yellow part of the gauge is concerning.



Thanks, Tom
AlamocitySS is offline  
Sponsored Links
Advertisement
 
post #2 of 13 (permalink) Old Apr 8th, 19, 05:17 PM
Admin/Super Moderator
Brian
 
69-Pace's Avatar
 
Join Date: Jun 2010
Location: Connecticut USA
Posts: 12,343
Garage
Exclamation Re: new cooling issue

Tom - These gauges - if factory installed or factory style have a resistor to "correct" the gauge. Also the sender is in the head on the drivers side. Both should be tested. Both may need replacement.

You can bench test the gauge and sender by following the referenced sticky. To do so you will need an Ohm's scale on a multi-meter. Also helpful if you have a potentiometer so you can send a known ohm to the gauge and see what it registers at which point you can either live with that scale or change senders, and or add resistance to get the needle where you would like it.

Here is the sticky on water gauge sender testing https://www.camaros.net/forums/19-el...ole-gauge.html

Brian
Larger Dave likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1969 Z11 Pace Car - L48 350cid/300hp - 4 Speed Muncie 12 bolt rear.

Super Moderator Team Camaro
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
to send me a private message
69-Pace is offline  
post #3 of 13 (permalink) Old Apr 8th, 19, 08:51 PM
Team Member
Darin
 
ilikeike's Avatar
 
Join Date: Jun 2013
Location: Stanislaus Co. Ca.
Posts: 1,214
Re: new cooling issue

I wonder where the water is going. Out the tail pipe or in the crankcase?
The oil isn't milky is it ?
dhutton likes this.

1968 Butternut Coupe,
TKO 600
9" narrowed 2"
(new Speedtech torque arm & mini tub setup being installed now.)
421" Dart SHP block.
3" drop front and back.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ilikeike is offline  
 
post #4 of 13 (permalink) Old Apr 9th, 19, 06:48 AM
Senior Tech
 
Join Date: Nov 2018
Posts: 433
Re: new cooling issue

Might want to get a pressure tester from the loan a tool deal at auto part store and check radiator for a pin hole leak. Those kind of leaks can typically not show up on the floor as the hole is so small the coolant evaporates when it hits the hot engine

with that said having 3-4" low of coolant in radiator should not cause a overheating issue
SoCal805 is online now  
post #5 of 13 (permalink) Old Apr 9th, 19, 07:25 AM
Senior Tech
Dave
 
Join Date: Dec 2005
Location: Tampa, Florida
Posts: 4,510
Re: new cooling issue

I might point out that 400 is a bigger number than 396. If you have a SBC 400 with a four barrel good heads and a cam you are making nearly fifty percent more power than a BBC 396. As such you will need a BBC HD radiator and BBC fan (I prefer the newer 7 blade over the period correct five blade), and proper fitting fan shroud which is a problem with a SBC Camaro.

Big Dave
Larger Dave is offline  
post #6 of 13 (permalink) Old Apr 9th, 19, 09:32 AM
Senior Tech
 
Join Date: Nov 2018
Posts: 433
Re: new cooling issue

Quote:
Originally Posted by Larger Dave View Post
As such you will need a BBC HD radiator and BBC fan (I prefer the newer 7 blade over the period correct five blade), and proper fitting fan shroud which is a problem with a SBC Camaro.

Big Dave
This fan shroud is for a BB (23") radiator used for a SB (motor mounted center of frame). What I have for my 327 using a 23" radiator

https://www.summitracing.com/parts/oer-3893814
SoCal805 is online now  
post #7 of 13 (permalink) Old Apr 9th, 19, 09:57 AM Thread Starter
Tech Team
 
Join Date: Aug 2018
Posts: 31
Thanks for all the input. I hadn't considered the fan size. I'll measure what is in the car. Now I'm wondering if I should shouldn't just have the radiator flushed and fully checked?
AlamocitySS is offline  
post #8 of 13 (permalink) Old Apr 9th, 19, 12:18 PM
Senior Tech
 
Join Date: Nov 2018
Posts: 433
Re: new cooling issue

Quote:
Originally Posted by AlamocitySS View Post
Now I'm wondering if I should shouldn't just have the radiator flushed and fully checked?
a quick pressure test using a loaner gauge will tell you instantly if the radiator is leaking....but it won't tell you if the cores are plugged up

You are losing coolant so it is leaking from "somewhere"....and a not free flowing radiator will run hotter.

Obviously a good radiator shop could tell you on both issues
SoCal805 is online now  
post #9 of 13 (permalink) Old Apr 15th, 19, 07:12 PM Thread Starter
Tech Team
 
Join Date: Aug 2018
Posts: 31
Re: new cooling issue

Ok, trying to figure this cooling issue out, I checked a few things and finally pulled the oil filler cap from the valve cover, passenger side.


Is this what I think it is, frothy oil from a blown gasket??

https://ibb.co/Sv5T4Yq
AlamocitySS is offline  
post #10 of 13 (permalink) Old Apr 16th, 19, 05:44 AM
Senior Tech
Travis
 
Join Date: Oct 2017
Location: Wyoming
Posts: 251
Re: new cooling issue

Possibly but doubtful. More than likely this is just condensation caused by not getting the car up to operating temps for a long enough period of time. Take it on a long drive and it will clear right up.
travisch is offline  
post #11 of 13 (permalink) Old Apr 16th, 19, 07:19 AM
Senior Tech
 
Join Date: Nov 2018
Posts: 433
Re: new cooling issue

^^^^, if the oil is chocolate milk....then you have a blown head gasket

as mentioned condensation inside the oil cap will cause what you see on it. Typically due to short drives where the motor does not operate at full temps
SoCal805 is online now  
post #12 of 13 (permalink) Old Apr 16th, 19, 04:41 PM Thread Starter
Tech Team
 
Join Date: Aug 2018
Posts: 31
Thanks guys. The oil was changed about 200 miles ago. It's slightly darker than I thought it should be, but Amber colored and thin looking, not cloudy.

I guess I'm back to the radiator being a potential issue. Can't explain why the cooling system is eating coolant.
AlamocitySS is offline  
post #13 of 13 (permalink) Old Apr 16th, 19, 04:53 PM
Moderator
____
 
DOUG G's Avatar
 
Join Date: Mar 1999
Location: Maryland, USA
Posts: 19,048
Garage
Send a message via MSN to DOUG G
Re: new cooling issue

pull the sparkplugs....that will also tell you if its leaking by the color of the plugs

68 Camaro~LSx ~all motor
1.54 60'--6.95 @ 98.45 660'--10.96 @ 121.53
DOUG G is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user 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.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Cooling system upgrade, 67, 350 Kiowa Heating & Cooling 14 Oct 8th, 18 03:15 AM
HELP COOLING QUICK. Overheating issues and not good Vintage A/C LYK2ROC Heating & Cooling 4 Jul 3rd, 18 06:34 PM
Pertronix Ignitor 2 Issue jimbo68 Electrical & Wiring 7 Jun 19th, 18 07:57 PM
Parade Duty Cooling Question 1969z11 Heating & Cooling 7 Mar 12th, 18 08:08 PM
Retro Electro RS Light Installation Issue VETJET Camaro Tech 5 Jan 11th, 18 08:21 PM

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

 
For the best viewing experience please update your browser to Google Chrome