Jump to content
Ultimate Subaru Message Board

Burping question on overheating Legacy


Recommended Posts

Hi Guys,

 

I’ve been searching the form for an answer to my question, but am not sure if I’m using the right search terms to find what I need.

 

I just had the timing belt changed on my 1998, 2.2 Legacy. My brother did the work for me and everything seemed to go great until we started the car up. It ran great, but then started overheating.

 

To make a long story short I think it’s because there still some air in the radiator system somewhere.

 

It seems to run great around the city, but when I get it out onto the highway it starts getting too warm. Specifically the reading would get up to about 2/3 when the temp normally sits at just below 1/2. This would happen when going up long hills and when I turn the heater vents off. When the temp starts to go too much above the halfway mark I turn the heaters on and that seems to help bring the temp down. I certainly would not call it stable though.

 

This morning when I looked the antifreeze reservoir was empty. I added some antifreeze directly to the radiator through the cap. It took about a cup of fluid, and then filled the reservoir. It seemed to help a little on the drive into work this morning. There was not as much overheating….but then the trip into work is much more downhill.

 

I did not have any overheating issues at all before the timing belt change...this is completely new. I also initially replaced the old TStat with an aftermarket one. I'm planing to get an OEM one after reading some posts here.

 

Ok, onto the question. I think there’s still some air in the system. Would you guys agree with this?? If there is, can I park the car on an uphill overnight and then check in the morning to see if some air works its way up to the top of the radiator?

 

I did do a search for burping but it only came back with three posts for slightly different engine types….mostly 2.5’s. Are the techniques the same for the two different engine sizes, or does it not make a difference?

 

I don’t want to waste you guys time if this has been asked a million times over….just point me to the correct search terms or to an older thread if it’s available.

 

Thanks!

Urban Coyote

Edited by Urban Coyote
Link to comment
Share on other sites

Search here for "burp", "burping", etc. I think these is even a link to a video.

 

2.5's are moody but I've had the same issue with 2.2's.

 

Usually removing the lower hose to drain the rad, then attaching it and taking off the upper hose to fill the engine until the top hose is full. Then connect it and top off the radiator.

 

That's all it usually takes on a 2.2.

Link to comment
Share on other sites

Burp it. Get the front of the car as high as possible, squeeze the top radiator hose over and over until no bubbles come out at the radiator fill port.

 

Start the car and do it all over again, until it's bubble free. Put the cap on and let it come up to temp. Shut off the engine and let it cool, the engine should draw coolant in from the overflow bottle.

Link to comment
Share on other sites

Thanks guys.

 

Yup, made the cardinal sin of putting an aftermarket t-stat in....I'm going to pick up a Subaru one after work today on the way home.

 

Excuse my ignorance, but what does the top radiator hose look like, and where abouts would I find it? Is it a large hose, or a smaller one?

 

Again, excuse my ignorance, I know just enough about cars to get myself into trouble :P

 

UC

Link to comment
Share on other sites

the top hose is on the passenger side of the rad and connects to the engine. burping on a hill, nose up will not hurt. but filling and idling the engine with the rad cap off untill it reaches full operating temp, temp guage reads normal and t-stat opens, will also work. once warmed up, if there is an air bubble, it should burp and the level of coolant will drop, fill rad the rest of the way and put on the cap. fill the over flow.

Link to comment
Share on other sites

Excellent! Thanks! I thought that was the one being referred to, but wanted to make certain. I watched my brother working with that one so had a pretty good idea. I have a pretty steep gravel ramp at my place that I will park the car on when I get home tonight. I will give a few of these ideas a try.

Link to comment
Share on other sites

Burp it. Get the front of the car as high as possible, squeeze the top radiator hose over and over until no bubbles come out at the radiator fill port.

 

Start the car and do it all over again, until it's bubble free. Put the cap on and let it come up to temp. Shut off the engine and let it cool, the engine should draw coolant in from the overflow bottle.

 

 

I gave this a try and didn't see much of anything in the way of bubbles....maybe a few. How much air is enough to cause problems? I will check the level of fluid in the morning.

 

UC

Link to comment
Share on other sites

I don't notice any gurgling and such, but with the winter tire on and road noise I may not be able to hear it.

 

I did check the overflow chamber this morning and some fluid had been drawn off so I'm hoping this may be a good sign.

 

When I tried the burping last night the car had not completely cooled off as I had let it sit about 2 - 2.5 hours. When I first went to squeeze the radiator hose it sent a spurt of fluid over the top of the radiator fill port...so I may ahve missed a bigger bubble there.

 

Anyway, if the issue persists I may just bite the bullet and take it into Subaru for a radiator flush and replacement of the aftermarket t-stat. If it still acts up after that then I'll get really worried!

 

UC

Link to comment
Share on other sites

Have you removed the coolant bleeder screw from the righthand side of the radiator? Try removing that screw and filling the system until coolant comes out the hole. That should do it. May take a couple of tries. Make sure your heat is on high.

Link to comment
Share on other sites

*Sigh* Nope, no change from yesterday.

 

It is strange though, if I only drove in the city I wouldn't have a clue in the world that something was not quite right as the temp behaves perfectly. It's only once I get onto the highway and specifically go up rather steep hills that the temp starts to climb, and almost as quickly when I go down a hill it drops again. Oddly enough, when I put the car in neutral and coast down a hill, it starts to climb again. If I put it into gear again on the same hill, the temp drops. Once I hit the city and start doing the start, stop. and wait at lights, the temp looks perfect.

 

Go figure......

Link to comment
Share on other sites

Thanks guys.

 

Yup, made the cardinal sin of putting an aftermarket t-stat in....I'm going to pick up a Subaru one after work today on the way home.

 

Excuse my ignorance, but what does the top radiator hose look like, and where abouts would I find it? Is it a large hose, or a smaller one?

 

Again, excuse my ignorance, I know just enough about cars to get myself into trouble :P

 

UC

 

Okay, but after replacing the thermostat, and connecting the lower radiator hose, disconnect the upper radiator hose at the radiator, fill with coolant till it takes no more, reconnect hose to radiator, fill radiator till it takes no more, remove burping valve on top of radiator located oposite to the filler cap, pour coolant into little hole until it takes no more. Oh yeah, do all of this with the heater temperature controller on your dash turned to the high temp side. Do all of this before starting engine. Also, since your brother just changed the timing belt, make sure he didn't disconnect the radiator fan control wires and forget to reconnect them :)

This worked for me after swapping a 2.5l engine.

James

Link to comment
Share on other sites

Did you ever change the t-stat?

 

Since it really hasn't "overheated" per sey and only gone up about 3/4 on the gauge then my money is still on the t-stat. An OEM should solve your problem. I had the same symptoms on a MY97 2.2 with the aftermarket in it. Idled fine and ran locally ok with a needle width below 1/2, but would creep up on the highway to 3/4 then move around a little then back down again.

 

After a drive check your lower radiator hose, bet you find it's stone cold, or at least a lot cooler than the top one. That's what happened to mine until I replaced the t-stat.

Link to comment
Share on other sites

Make sure your heat is on high.

 

Oh yeah, do all of this with the heater temperature controller on your dash turned to the high temp side.

 

 

You guys, the heater core in a subaru is a fulltime part of the cooling system. There is not a valve in the hose that opens or closes flow to the core. There is no change in what happens to the water flow through the core based on the blend door. Heater core is *in the loop* 100% of the time.

 

There really is no need to even look at were the temp control settings are for filling and burping.

Link to comment
Share on other sites

When I replaced the 2.2 in my impreza I had the same thing happen. Big air bubble and the engine got hot quick. Then I read the owners manual and it says regarding filling the coolant system:

 

"Slowly pour the coolant and fill to the radiator filler neck and to the reserve tank's "FULL level mark. Do not pour the coolant too quickly, as this may lead to insufficient air bleeding and trapped air in the system."

 

"Start and run the engine for more than five minutes at 2000 to 3000 rpm."

 

Next I followed the above directions and the engine got hot quick again, but this time it went about 2/3 of the way to red on the temp guage and then the thermostat opened and it cooled down to normal ( about 1/3) I topped off the reserve tank the next morning and the rest is history.

 

Try the 2000 - 3000 rpms for 5 minutes and I bet it will work.

 

Good luck

 

Daniel

 

ps- I was using oem thermostat!

Edited by crockettbrat
Link to comment
Share on other sites

If you've got a big bubble, and particularly a non OEM thermostat this hasn't worked for me.

 

Perhaps you'll be luckier.

 

Search here for the video on burping. I also raise the front of the car on the side the rad cap is on. Often when having problems I pull it up on one rhino ramp.

 

Don't forget to drain it (I use the lower hose) Before trying to fill through the top hose.

 

It's a pain sometimes. But you should really have it figured out by now between the posts and suggestions here.

Link to comment
Share on other sites

Ok, I bit the bullet and took my roo into the dealer for the thermostat change and to have the radiator filled up properly. I don't have enough confidence in my abilities just yet to do the whole procedure with the draining and re-filling on my own, so I took it in and told them exactly what I wanted done.

 

On the drive home everything worked perfectly! The temp went to the just below half way and stayed there rock solid. Whether is was a bubble, or the t-stat is anyones guess....I'm just glad everything is working properly again!

 

I'm definitely printing off all of this info and stashing it in the car though.....you guys are the best!!

 

Urban Coyote

Link to comment
Share on other sites

After all that you took the easy (and expensive) way out?

 

Sometime you just have to get it fixed. I don't have a garage, or a lot of tools, or 'mechanical intuition'. If I tried and something went wrong, or I made it worse then what? Unfortunately I don't have another car to use in case something happens to the roo I have. I do the best I can with what I have and am learning.....what more can I say than that?

Link to comment
Share on other sites

Nothing. No harm intended.

 

At the very least you did the research to find out what the problem was and how to fix it.

 

At the very least you were able to keep the mechanic honest.

 

Not as fulfilling as fixing it. But you didn't get "taken" by not knowing what needed done.

 

Not bad at all - really.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...