sam888 Posted January 1, 2009 Share Posted January 1, 2009 I did a search on this problem and these are the closest that describe what I have but not quite. http://www.ultimatesubaru.org/forum/showthread.php?t=33438&highlight=intermittent+heater http://www.ultimatesubaru.org/forum/showthread.php?t=86957&highlight=intermittent+heater Here is what I have 1991 Leg LS Wagon; 217k miles Orig Engine. Radiator replaced 5 months ago but problem was already there. I think the car overheated once when me and my wife were at the top of Hurrican Ridge Wa needle was past the half mark it did not reach the red zone. I pulled over right away and luckily coasted down in neutral to the ranger station where I was able to put water in it and made it home without problems since the leak was slow. Replaced the radiator at that time. The car warms up fine, temp gage gets to normal at normal rate and stays normal throughout the various driving conditions. I only get heat if the engine is reving at about 2000 rpm. If I am idline at below the air goes cold. I noticed that if I am going down hill or parked with front pointing down hill It is harder to get the heat to come thru even if I rev the engine. Coolant level is fine and the car does not overheat. Anyone have any ideas? Thanks! Quote Link to comment Share on other sites More sharing options...
Durania Posted January 1, 2009 Share Posted January 1, 2009 -Radiator Cap -Air bubble in the system -Water pump -Clogged heater core? Quote Link to comment Share on other sites More sharing options...
Skip Posted January 1, 2009 Share Posted January 1, 2009 sounds like it may need a good "burbing" many posts on how to do it. basics are get the front up on ramps let it run from cold with cap off watch for burping taking place at filler neck (keep drip pan under rad) Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 1, 2009 Share Posted January 1, 2009 What is the condition of the timing belt? You're belt may be glazed and slipping over the waterpump pulley, reducing water circulation. Although, if you are losing coolant regularly, you may have the beginings of a head gasket issue. Sounds excactly like what happens. Espescially the no heat going down hill. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted January 1, 2009 Share Posted January 1, 2009 sounds like it may need a good"burbing" many posts on how to do it. basics are get the front up on ramps let it run from cold with cap off watch for burping taking place at filler neck (keep drip pan under rad) The burping is a good idea. Also, it is possible that you have a bad head gasket which allows exhaust gas to enter the cooling system. This causes engine over heating and poor heater performance. That could be causing the need for 'burping." Car heating systems rely on coolant flow through the heater core to provide warm air to the cabin. A "gas" added to the cooling system reduces heater efficiency. I had a 91 Leggie that blew a head gasket resulting in pressurizing the cooling system resulting in a leaky radiator. Is it possible that same thing happened to your radiator? The early 2.5 engine introduced in 1997 gets the bad rap for blowing head gaskets, but the earlier 2.2 engine (as in your car) can still blow a head gasket. Check your radiator over flow for bubbles when the engine is warmed up and running. If you see bubbles, you have a head gasket issue. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 1, 2009 Share Posted January 1, 2009 (edited) assuming your details are correct (the radiator fixed the leak): your heater core is clogged. remove both hoses going into the firewall and flush the heater core out. probably best to just plan on replacing those hoses and clamps too, good chance they are not in good enough shape to reliably pull off and reuse. Edited January 1, 2009 by grossgary Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 1, 2009 Share Posted January 1, 2009 assuming your details are correct (the radiator fixed the leak): your heater core is clogged. remove both hoses going into the firewall and flush the heater core out. I disagree. The fact that the heat goes awy when the car is pointed downhill is a clear sign of an air pocket developing in the cooling system. This is ussually from a bad HG, but can happen from other leaks or a bad Radiator Cap. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted January 1, 2009 Share Posted January 1, 2009 I disagree. The fact that the heat goes awy when the car is pointed downhill is a clear sign of an air pocket developing in the cooling system. This is ussually from a bad HG, but can happen from other leaks or a bad Radiator Cap. ditto on Gloyale's comments. If the heater core was plugged, you would not get any heat output, or very minimal heat. Also, the heat output would be constantly poor, as coolant always moves minimally through the heater core. The air pocket theory is a better idea, as the air pocket is not a constant. Sometimes coolant is moving through the heater core, sometimes not much, depending on the air pocket, and the water pump circulating varying amounts of coolant/air pocket. As Gloyale suggests..........a bad HG, or a radiator cap. My vote is a bad head gasket. Quote Link to comment Share on other sites More sharing options...
Qman Posted January 1, 2009 Share Posted January 1, 2009 Put a thermostat in it. Sounds like there isn't one. Do you get heat only when driving? Or does it work when you are sitting still with the engine revving over 2K? Quote Link to comment Share on other sites More sharing options...
Durania Posted January 2, 2009 Share Posted January 2, 2009 Put a thermostat in it. Sounds like there isn't one. Do you get heat only when driving? Or does it work when you are sitting still with the engine revving over 2K? If a thermostat is not present, wouldn't that point to a previous cooling/over-heating condition? Quote Link to comment Share on other sites More sharing options...
ericem Posted January 2, 2009 Share Posted January 2, 2009 So if I understand what you are saying. You mean the car is running fine, no overheating issues, but the heat out your vents is not coming out unless you rev it up. I ran into the same issue after putting in my new radiator. At the same time I also replaced my thermostat (only use OEM and get a gasket) and my radiator cap, which are important parts and can give you symptoms you are getting. The following day re-bled the system with the car parked(be sure engine is cold obviously before doing anything) on a uphill slant, engine running, and open up the radiator cap, squeeze the top hose a continously to get out any air and continue adding coolant untill it is filled to the top of the lid actually to the first notch so you can put the lid on obviously. Watch it, the fluid should stay at the same height and this way know it is filled and there is no air in the system otherwise keep pumping that top hose. Also be sure to put the heat on with the temperature on the hottest side and fan on lvl 3-4. Clean up the cap to, there might be some crap on the rubber. The issue should not occur after this as long as the temp gauge sensor is working correctly. There have been other discusions and someone suggested the heatcore could be clogged. Lets not jump to conclusions though. Quote Link to comment Share on other sites More sharing options...
sam888 Posted January 2, 2009 Author Share Posted January 2, 2009 I have reviewed all the post on my questions and I am not surprised at the wealth of information that I get from this message board. My father in law thinks I am a genious because I fixed his car when no mechanic in town could based on feedback I got from this message group. My thanks to all of you who have posted. Based on all of your suggestions I think the problem is probably caused by air/gas in the system although a plugged or retricted heater core is still a possiblity. I think I will start by replacing the radiator cap and doing what is referred to by some of you as a "burping". I have not looked at fluid loss or leaks that someting I will do. If that doesn't work then I willr replace the thermostat after that I will do a heater core purge/flush. Someone asked for the condition of the timing belt; I am not sure but it was replaced at about 200k miles. It was also mentiponed that the HG leak can be the cause of gases/air in the system if that is the cas I should be having overheating problems which I am not having although it is winter. Can it still be a HG even if I don't experience engine overheat? Also if the HG is shot how soon should I be thinking about replacing/fixing it? At the moment the car runs fine. Thanks again for all your help. Quote Link to comment Share on other sites More sharing options...
Durania Posted January 2, 2009 Share Posted January 2, 2009 Yeah I think the radiator cap and cooling system burp will be the best way to start going about diagnosing your problem. I thought I had some head gasket problems because my BRAT was getting warm, not hot going down the road and losing heat out the vents. Turned out to be a 5 dollar radiator cap. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted January 2, 2009 Share Posted January 2, 2009 Can it still be a HG even if I don't experience engine overheat? Also if the HG is shot how soon should I be thinking about replacing/fixing it? At the moment the car runs fine. It can. You won't have any issues with overheating for a while, then one day when the coolant reaches a critically low level, you'll overheat. Worst cases, there is so much airspace trapped in the motor that the temp gauge reads cold, since no water is touching it, meanwhile the motor is cookin. Give it a good burp and fill, check or replace the rad cap, then watch carefully for bubbles in the overflow, or any loss of coolant over time. Quote Link to comment Share on other sites More sharing options...
9098 Posted January 3, 2009 Share Posted January 3, 2009 Had the same problem on my 1990 Legacy. 10 to 1 if you watch your temp guage closely when the heat goes away...you will notice the temp going up quick. I was pulling my hair out. It worked fine for weeks and would overheat at the worst times. It's the HG. The 2.2 is not bullet proof. Just twice as good as the 2.5. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.