Welcome to the North American Subaru Impreza Owners Club Friday September 19, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

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.
Reply
 
Thread Tools Display Modes
Old 01-04-2007, 01:06 PM   #1
greenhand
Scooby Newbie
 
Member#: 97677
Join Date: Oct 2005
Location: Seattle, WA
Vehicle:
1998 Impreza 2.5 RS
Black

Unhappy Thermostat/Temperature Problem on my 98' RS

I have a 98 RS that is pretty much stock. Near the end of August I was have thermostat issues with it sticking and my car overheating. To sidestep the problem while on a roadtrip we just removed the thermostat and we've not had another problem since. Ok, so this past weekend I decided that my gas milage was suffering from me being lazy and I purchased a new thermostat and o-ring from the local Subaru dealership. Ran great...for about 2 days...overheating again from what appears to be another STICKING THERMOSTAT!!! Is this a recurring problem with these cars, or is there possibly another reason why my car chooses what temperature it wants to be at, pinned at the top of gauge one moment, then down to half and normal operating temperature the next. This is so frustrating, any suggestions?
* Registered users of the site do not see these ads.
greenhand is offline   Reply With Quote
Old 01-04-2007, 01:20 PM   #2
legacy1907
Scooby Specialist
 
Member#: 94024
Join Date: Aug 2005
Chapter/Region: South East
Location: Raleigh, NC
Vehicle:
05 WRX CGM
95 YJ Flat black

Default

if you want to test the thermostat you can heat water up in a pot till it boils and dip the thermostat in to see if it opens without problems and then you can tell whether its the thermostat or something else
legacy1907 is offline   Reply With Quote
Old 01-04-2007, 07:36 PM   #3
SiFuSpEc
Top Scoob 008
 
Member#: 77299
Join Date: Dec 2004
Location: Bedford, Ohio
Vehicle:
'05 2.5RS
#78 ST, MAXIMUM ATTACK!

Default

try spending a bit longer to burp the car...

squeezing both top and bottom hoses, and letting the car heat cycle a couple times..
SiFuSpEc is offline   Reply With Quote
Old 01-04-2007, 07:57 PM   #4
greenhand
Scooby Newbie
 
Member#: 97677
Join Date: Oct 2005
Location: Seattle, WA
Vehicle:
1998 Impreza 2.5 RS
Black

Default

Does anyone have a cooling system diagram?
greenhand is offline   Reply With Quote
Old 01-04-2007, 10:56 PM   #5
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
QuickSilver Metallic

Default

Head gaskets.
Patrick Olsen is offline   Reply With Quote
Old 01-04-2007, 10:57 PM   #6
kickitjp
Scooby Specialist
 
Member#: 60035
Join Date: Apr 2004
Chapter/Region: PRSIC
Default

Quote:
Originally Posted by Patrick Olsen View Post
Head gaskets.
Seriously. Check your coolant for oil.
kickitjp is offline   Reply With Quote
Old 01-05-2007, 12:06 PM   #7
greenhand
Scooby Newbie
 
Member#: 97677
Join Date: Oct 2005
Location: Seattle, WA
Vehicle:
1998 Impreza 2.5 RS
Black

Default

I did. I'm in denial right now. I know it's a 98...Headgasket. Yes, there is that very small oil sheen when I open the radiator. I took the thermostat out for the time being. From reading around, I should just get the OEM engine gasket set from my local Subaru Dealership? Also, does anyone have a PDF version of the Hayes or Service manual for the DOHC 2.5? Thanks for everyone's help! Looks like the cherry picker will go into use within a few weeks.
greenhand is offline   Reply With Quote
Old 01-05-2007, 12:21 PM   #8
greenhand
Scooby Newbie
 
Member#: 97677
Join Date: Oct 2005
Location: Seattle, WA
Vehicle:
1998 Impreza 2.5 RS
Black

Default

Also, are there any easy, fairly affordable changes I should make while pulling my engine out and apart? Obviously I might need to machine the heads if they are warped, any aftermarket options I should be looking at? Any reccomendations are greatly appreciated. Thanks.
greenhand is offline   Reply With Quote
Old 01-05-2007, 12:46 PM   #9
Legacy777
Scooby Guru
 
Member#: 4800
Join Date: Mar 2001
Chapter/Region: TXIC
Location: Houston, Tx
Vehicle:
1990 Legacy & 97 OBS
AWD 6MT EJ22T AWIC Swap

Default

How are you bleeding the cooling system? There should be a burp/bleed screw on the top of the passenger side of the radiator. This needs to be removed in order to properly bleed/burp the radiator of air.

In addition, there is a common failure point in the front on the passenger side end tank on the top...directly in front of where the top radiator hose enters. It will crack there, let coolant leak, and air back in when things cool.
Legacy777 is offline   Reply With Quote
Old 01-05-2007, 12:55 PM   #10
greenhand
Scooby Newbie
 
Member#: 97677
Join Date: Oct 2005
Location: Seattle, WA
Vehicle:
1998 Impreza 2.5 RS
Black

Default

No leaking coolant in the engine compartment, yet losing coolant anyway. I turned the heat on high on the floor, ran the car with the radiator cap off while filling the coolant up, and waited for all the air to bleed out of the system...
greenhand is offline   Reply With Quote
Old 01-05-2007, 01:01 PM   #11
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
QuickSilver Metallic

Default

Quote:
Originally Posted by greenhand View Post
No leaking coolant in the engine compartment, yet losing coolant anyway. I turned the heat on high on the floor, ran the car with the radiator cap off while filling the coolant up, and waited for all the air to bleed out of the system...
Definitely make sure you remove the bleed/vent screw from the passenger side of the radiator. I've never had any issues with air in my cooling system, and I don't do anything special to fill it - engine off, remove radiator cap, remove vent screw, fill until the radiator's full, fill the overflow bottle to the "Full - Cold" line, done.

Quote:
Originally Posted by greenhand View Post
Also, are there any easy, fairly affordable changes I should make while pulling my engine out and apart? Obviously I might need to machine the heads if they are warped, any aftermarket options I should be looking at? Any reccomendations are greatly appreciated. Thanks.
You can do performance stuff like Delta cams or getting the heads ported and polished. There are no aftermarket head options for the Subie engines. The OEM gaskets should work just fine, although some people use Cometic gaskets instead.

Pat
Patrick Olsen is offline   Reply With Quote
Reply

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
need some help with my 98' RS rlig Normally Aspirated with bolt-on Forced Induction Powertrain 8 06-10-2006 04:48 PM
rs mudflaps wont fit on my 05 rs. rsracer2005 Interior & Exterior Modification 6 03-30-2005 11:37 AM
Steering Problem on my '02 RS? Rosso_Corsa Normally Aspirated Powertrain 1 12-31-2003 01:35 AM
most recent pics of my 98' RS SubeDonC Member's Car Gallery 7 09-09-2002 11:47 AM
I have the terrible Cold clutch shudder problem with my 2001 RS scootr Normally Aspirated Powertrain 16 12-21-2000 10:53 PM


All times are GMT -4. The time now is 10:22 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.