Welcome to the North American Subaru Impreza Owners Club Friday January 19, 2018
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Subaru Models > Legacy Forum

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 08-24-2004, 03:10 AM   #1
Scooby Specialist
Member#: 38829
Join Date: Jun 2003
Chapter/Region: NWIC
Location: Tigard, OR
Not your usual 1997
Legacy GT

Question I'm confused. Cooling system problems...

So I was idling in the park, talking to some friends, nice summer night, and my car starts overheating, and at the same time throws a CEL. Not sure what's going on, I check the coolant level. It had boiled over and there wasn't too much in the reserve tank. However, I happened to be carrying around a gallon of filtered water, so I dumped it in to bring the level back to normal, and top off the radiator as well after it cools a little. Engine cools back down, but then the temp keeps going up and down. I'm VERY confused at this point.

I just replaced my thermostat a month and a half ago and I've driven the car every day since, so I am skeptical that it just went bad. I finally found an OBDII scanner, and pulled the code. I get P1502 and look it up online - "Radiator Fan Function Problem". So I go outside, start the car up, drive it around until the engine gets warm, then park it and wait for the fans to go on. One kicks on, then I sit there and rev the engine to make it hot. Other fan kicks on. Seem to be working fine to me! So I drive around again. Sure enough, temp goes up after several miles. I turn the heater on, and HOT HOT air dumps out. Hotter than I've ever felt from a car heater. That helps to keep it low enough until I park. I go to the store, get back in the car, and it is perfect all the way home. I drive it hard, and it stays at the perfect temperature.

Any ideas??? I think tomorrow morning I'm gonna do an oil change (a little overdue) and flush my whole cooling system. I think that the coolant getting so hot loosened up some junk in my radiator, 'cuz my coolant looks a weird color, and I saw some chunks floating in the overflow tank.

Please, anyone with cooling system experience feel free to chime in and give me the solution to my crazy car's problem. Anyone know what that CEL code REALLY means?

* Registered users of the site do not see these ads.
fastenova is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 08-24-2004, 03:26 AM   #2
Scooby Specialist
Member#: 53410
Join Date: Jan 2004
Chapter/Region: SWIC
Location: Tucson, AZ / Port Angeles, WA


sounds like possible head gasket issues...i dunno about the CEL code though...kinda interesting.
fibuz is offline   Reply With Quote
Old 08-24-2004, 12:16 PM   #3
Scooby Newbie
Member#: 56015
Join Date: Feb 2004
Chapter/Region: RMIC
Location: Denver, CO
02 WRX Wagon
05 XT Forester


Originally Posted by fastenova
'cuz my coolant looks a weird color,...
Have your coolent tested for hydrocarbons to make sure you dont have oil in there. Could be a possible HG issue but the CEL seems weird.
bhall is offline   Reply With Quote
Old 08-24-2004, 09:21 PM   #4
Scooby Specialist
Member#: 12535
Join Date: Nov 2001
Chapter/Region: NWIC
Location: Idaho slash Washington
vf39 06 5MT XT
92 Legacy Rally EG33'd


my guess, the level of coolant isnt up to where its supposed to be and so when the car gets warm there is a pocket of realllllly hot air or steam at the top of the system, the same place the coolant temp sensor is. Since you have replaced the thermostat we know thats working fine, when it cycles i think that is when the temp goes up and down.
biggreen96 is offline   Reply With Quote
Old 03-06-2005, 08:59 PM   #5
Scooby Newbie
Member#: 82215
Join Date: Mar 2005
Default Random Overheating on '97 2.5GT

I am having the same issues. After blowing a radiator after not noticing how hot the car got 300 miles into a roadtrip. I had the radiator changed and cooling system flushed and checked for cylynder head leaks. No exhaust in my cooling system, pressure test ok.

Now when I drive at the most random times the car overheats or comes close to it, to later go back to normal after I let it cool off in the below-zero weather. I did not have the thermostat replaced, nor the radiator cap, just the radiator. My system should have bled itself of air by now I figure, it really does it automatically my subaru mechanic said.

The problem does not go away, and especially after driving for 20 or 30 miles at 80-100 mph, the car just overheats when I get off the exit and drive on streets.
If the thermostat is open, it should stay open and not close in the middle of driving on the interstate. If there is air in the system, it should have bled itself by now since I filled the radiator tank to the top when it was cold.

Thoroughly confused. I've never had problems with this car. I am the 2nd owner with 94K miles. The 1st owner changed head gaskets at 60K miles.
boris1 is offline   Reply With Quote
Old 03-06-2005, 09:05 PM   #6
Scooby Specialist
Member#: 41012
Join Date: Aug 2003
Chapter/Region: E. Canada
1998 Legacy L


Get a compression test done. Overheating 2.5L almost always seems to be a HG
sha_zapple is offline   Reply With Quote
Old 03-06-2005, 09:14 PM   #7
Scooby Specialist
Member#: 58329
Join Date: Mar 2004
Chapter/Region: MWSOC
Location: MN
2005 Baja Turbo 5mt
Garnet Red Pearl


yeap....happened to me on my new used car on saturday?***....but found out that oil was in my coolant the day before! HG for sure.....my car overheats for like 5 min....then after that....seems to be working fine?***
illegal2.2 is offline   Reply With Quote
Old 03-06-2005, 10:33 PM   #8
MY99 2.5GT
Scooby Specialist
Member#: 5030
Join Date: Mar 2001
Chapter/Region: MAIC
Location: Martinsburg, WV, USA
1999 Legacy 2.5GT
12 Legacy GT 13 Armada


Compression test won't always show variance when the head gasket leaks. I had mine replaced at 58k under warranty. I took it in after an overheat and they did a compression test and found a lower number in cylinder 1.

I just hit 90k and had another over heat. I see the exact same symetems of the leaking head gasket before: oil in the overflow tank, bubling in the overflow tank when barely starting to get warm.

A tip for properly refilling the coolent system after flushing it or after an overheat. You will need to top the radiator off then fill the overflow tank. Run the car at 2500 rpm until the heat gauge shows a slightly above normal. While the car is still running check for air bubbling in the overflow tank. Don't let the car get too hot but let the bubbling continue for a minute or two then shut the car off. Let the car cool for a while and watch the coolent get sucked out of the overflow tank. Repeat this process until coolent no longer gets sucked out of the overflow tank.

If you don't fully refill the cooling system it will have problems with up and down temps during normal driving. Hot air bubbles in the coolent stream really hurt the systems ability to cool the car.

If you do all this making sure to fully fill the cooling system and it still has heat trouble or bubbling in the coolent stream I would either take it to a mechanic and get the head gaskets replaced or try a bottle of Bar's Leaks Head Gasket repair. I just finished putting the additive in my cooling system and will keep you guys updated as to whether or not this stuff works.

MY99 2.5GT is offline   Reply With Quote
Old 03-06-2005, 11:12 PM   #9
Russell Rogers
Scooby Specialist
Member#: 27261
Join Date: Oct 2002
Chapter/Region: NWIC
Location: Wa
I'm Ron Burgundy?


Head gasket that is all.
Russell Rogers is offline   Reply With Quote
Old 03-07-2005, 08:45 AM   #10
NASIOC Supporter
Member#: 30669
Join Date: Dec 2002
Chapter/Region: Tri-State
Location: USA, North NJ, 07456
1998 Legacy 2.5GT
Silver Sleeper BK, 5MT


Having the front of the car on ramps helps bleeding the cooling system as well.
Park it there, pull the cap and start it up. Squeeze the radiator hoses a bit to force air out, keep the heater on hot.

Add coolant to the radiator until you can't get more in then replace the cap.

Keep the tank at the proper level.

Not all cooling systems will self bleed, some are a real pain.
Charlie-III is offline   Reply With Quote
Old 04-16-2005, 11:15 PM   #11
MY99 2.5GT
Scooby Specialist
Member#: 5030
Join Date: Mar 2001
Chapter/Region: MAIC
Location: Martinsburg, WV, USA
1999 Legacy 2.5GT
12 Legacy GT 13 Armada


Bar's Leaks worked. Ive had it in for about 2 months now. Drove it easy for the first month and have driven the snot out of it for the second month. Still no sign of overflow tank bubbling.

I will caution you to make sure the coolant system is totally flushed. I managed to clog the radiator cap allowing coolant to get out into the overflow tank but it couldn't get back in. Another good flush took care of it. $10 and a day and a halfs work was much better then $1100 for replacement gaskets and labor.

MY99 2.5GT is offline   Reply With Quote

Thread Tools
Display Modes

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
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cooling system problem gakusya Service & Maintenance 15 02-11-2011 10:00 PM
"Burping" Cooling System Problems.. STI_KLR Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 31 11-03-2008 04:16 PM
Cooling system problem - car idles at 3k racer_x Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 5 10-22-2008 02:28 PM
i have a big cooling system problem! TheBryman Service & Maintenance 11 06-12-2007 03:21 PM
Cooling system problem? taphonomist Service & Maintenance 0 04-17-2005 05:40 PM

All times are GMT -4. The time now is 06:34 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2018 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.