Overheating in '91 Subaru Engine

Reply

  #1  
Old 07-02-06, 12:18 PM
Member
Thread Starter
Join Date: Jul 2006
Posts: 1
Overheating in '91 Subaru Engine

Hi. I have a 1991 Subaru Legacy with AT. It's in mint condition and has 310,000 miles on it. I've had the oil changed ever 3k miles so I attribute this to the longevity of the engine. We've had very little trouble with it except for the following:

After about 20 minutes of driving, the car will overheat for no apparent reason. We've installed a new radiator, new hoses, new thermostat and had all heater hoses replaced.

The stange thing about it overheating is that it only gets hot on one side of the radiator. When you open the radiator cap and let off the pressure, the coolant and heat gauge return to a normal operating temperature immediately.

Any suggestions? Thanks.
 
Sponsored Links
  #2  
Old 07-02-06, 01:18 PM
LouBazooka's Avatar
Member
Join Date: Dec 2005
Posts: 553
Somebody mentioned air bubbles in cooling system a while ago, I guess it is possible but, in any case with so many miles on engine I'd go ahead and replace water pump as well, even timing belt too. ( it's about the same labor in most cars ). Parts are cheap.
 
  #3  
Old 07-02-06, 03:20 PM
Member
Join Date: Feb 2005
Location: Michigan
Posts: 335
did you burp the system after you replaced the radiator tstat and hoses?
 
  #4  
Old 07-02-06, 04:18 PM
DaVeBoy's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Mar 2006
Posts: 1,665
Originally Posted by LouBazooka
Somebody mentioned air bubbles in cooling system a while ago, I guess it is possible but, in any case with so many miles on engine I'd go ahead and replace water pump as well, even timing belt too. ( it's about the same labor in most cars ). Parts are cheap.
Why stop there. Just get a whole new car!
 
  #5  
Old 07-03-06, 09:17 AM
davzack's Avatar
Member
Join Date: Jun 2006
Posts: 304
Exactly how much pressure is being generated? Try this, if you start the car and run it for just a couple of minutes...not enough to get it too hot...and then take off the radiator cap, are you getting a lot of air/pressure? I'm thinking that you may have developed a head gasket leak...especially with the miles you have on the engine. In your particular case, you may be getting hot exhaust gases blown into the cooling system...
 
  #6  
Old 07-03-06, 02:52 PM
DaVeBoy's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Mar 2006
Posts: 1,665
Originally Posted by davzack
Exactly how much pressure is being generated? Try this, if you start the car and run it for just a couple of minutes...not enough to get it too hot...and then take off the radiator cap, are you getting a lot of air/pressure? I'm thinking that you may have developed a head gasket leak...especially with the miles you have on the engine. In your particular case, you may be getting hot exhaust gases blown into the cooling system...
And if that is the case, many garages have a tester they put to your open radiator where the cap goes and test for exhaust gas in the water.
 
  #7  
Old 07-03-06, 05:15 PM
Member
Join Date: Jun 2006
Posts: 338
You replace the radiator cap yet those little buggers do make a difference, are the fans coming on. The bleed the air out of the system run it with the cap off for about 10-15mins and rev it every once in a while.


If it is not consuming coolant?

You can rent a cooling system pressure tester at a parts store and see it if holds pressure

For the price of having a shop pressure test the system you can buy the tester.

Also there is kit that is around $70 that comes with a dye that changes color for testing for exhaust gases in coolant usually you can only find those from hard core automotive tool places like matco, snapon websites.
 
Reply

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'