97 outback overheats above 35mph

[Deeron]

Hi all, I'm new here and just bought a 97 outback and have been having overheating issues.  A mechanic did a leakdown test and determined that it was a leaking radiator, so I replaced the radiator along with the thermostat, and the upper radiator hose (the aftermarket lower hose didn't fit).  The engine runs great and drives fine around town, but when I take it on the freeway it overheats.  It'll run well for anywhere from 2 minutes to an hour until the temperature suddenly rises.  It takes about 30 seconds to go from normal temp to red line.  If I stop for a minute and run the fan then it will return to normal temp and I can drive another couple of miles before the problem develops again.  I took it to another mechanic who did another coolant leakdown test and he said the system held pressure just fine.  

 

Any ideas?  I'm worried that it's a head gasket, but shouldn't that show up in a leakdown test or wouldn't it also overheat at low speeds? Could the thermostat just suddenly close? 

[987687]

Did you have a subaru OEM thermostat from the dealer installed? If not, that's probably the cause. The aftermarket ones suck.

 

It very may well be headgaskets... If you open the overflow cap NOT THE RADIATOR CAP, do you see bubbles coming out? That's a good sign of headgasket issues.

Also, when it overheats, does the heater stop working? If so, it's probably a headgasket.

 

But check to make sure they used a subaru thermostat first.

[idosubaru]

1.  are the overheating symptoms identical before any of the radiator/thermostat work - or are they different?

 

2.  properly bleed the coolant - they are notoriously unforgiving if any air in the system.

3.  test for combustion gases/hydrocarbons in the coolant.  that will verify head gaskets are bad or good.

 

these tests aren't helpful on this engine, don't waste your time with these:

a. compression

b. leak down

c. coil/coolant mixing

 

your symptoms don't sound like head gaskets - they sound like a cooling system not flowing enough which would suggest a clogged radiator or stuck thermostat. 

radiator is out since you replaced it.

 

so thermostat - if it's an aftermarket then get a Subaru or Xacta tstat, aftermarkets are like childs toys and problematic.  i don't honestly think that's your issue but it's cheap/easy enough that it should be checked.

[ivans imports]

headgasket

[Rooster2]

headgasket

yep head gasket........when said that the temp suddenly spikes, that is a dead give away that it is the head gasket. Since you just bought the car, I suspect previous owner sold the car because he figured out that over heating was head gaskets. Maybe you can get some of your money back, or have previous owner chip in on paying for the head gasket repair.

[Deeron]

Thanks for all of the responses, guys.  Since there are some conflicting opinions, I'll try to answer your questions to see if it clears things up.

Here's some additional info:

 

The overheating issues have gotten worse since replacing the radiator and thermostat. Originally, it just overheated a couple of time, and when I added coolant I could drive it for a few hours before the problem returned.  Now it happens every time I try to drive.  When it first overheated I didn't really pay attention before it happened, I just happened to look at the temp gauge and noticed the engine was hot.  

 

I got the thermostat from Napa, and it was cheap.  

 

I'm pretty sure the heater continues to work while it's overheating, but I didn't take notice of that.  I ran it full blast the whole time though.  

 

What I don't get is that if it's a clogged cooling system - either at the thermostat or radiator - than why would it cool perfectly fine for a while, then just suddenly spike? 

 

I bought the car from my uncle, and I'm sure he's honest, but I doubt he'll give me a dime. 

[987687]

Your first thing is to get a subaru thermostat. This picture speaks for itself on the topic.

 

 

 

So change that, burp the system properly (search on here how to do it), and see how it goes.

 

The sudden spike still sounds like headgasket, but you may be lucky...

When it's overheating, see if the heater works, and see if one radiator hose is significantly hotter than the other (don't burn yourself...)

 

What happens with a bad headgasket, is you get lots and lots of air (exhaust actually) in the system. Since the pump can't pump air, the heater doesn't work because coolant can't flow, the engine overheats, etc.

Edited December 14, 2013 by 987687

[Deeron]

OK.  I'll try the new thermostat and see what happens.  

 

The car has 134k miles on it.  It runs great (when it's not overheating) but given that it has overheated a few times now, should I worry about engine damage besides the gasket?  I drove the car to visit family, and don't have access to tools or a shop, so I'll have to have a mechanic do the work if it's a head gasket.  Do you think it's worth it, or am I going to just run into more problems because of excessive engine wear?  

[987687]

130k miles on the original headgaskets? Sorry to say, it's likely gaskets. If you haven't overheated it too bad, it's worth replacing. My family has a 99 that had the HG's replaced preventatively. It has almost 200k now running perfectly.

[idosubaru]

if it wasn't plunged into the red and abused a lot it should be fine.  will depend on oil condition and how it faired during the overheating process.  they are often replaced without issue.

 

the heads never crack or warp so simply resurface them and install new Subaru gaskets and you're done.  pressure testing and checking for warpage are a waste of time/money on these heads.

 

if it was like this when or shortly after you bought it, the condition was pre-existing.

[Deeron]

Yeah, it definitely overheated pretty good the first time.  I usually don't pay much attention to the temp gauge when I'm driving, so I didn't notice anything until I got out of the car and noticed steam coming from under the hood.  I let the cooling fans run for a while and added coolant after a bit, but the engine wouldn't really turn over until I left it sitting for another 20 min.  I had a bad battery at the time, so that could have been related.  Since then, it starts and runs pretty smoothly.  If I were at home and could do the work myself then I would just try to fix it.  The mechanic quoted me 2k for the gasket job, but I bet there will be at least another 500 bucks of the "while we're doing this" stuff.      

 

 I had the car for about 3 weeks before anything happened, and I put at least 1000 miles on it before it overheated.  

 

On a related topic, I really don't understand why cars don't come with warning alarms for temperature and oil pressure.  Just a little light on the dash really isn't enough for me, though I guess some people see that stuff right away.   

[1-3-2-4]

I almost always look at my dash when I'm driving.. I guess it's old habits, I know where the temp sits when it's level Just between the little water and F on the temp picture, like the others said having no heat is a dead giveaway, and if it was during the early summer like me 2 years ago turning on the AC makes it overheat that much quicker because of the condenser in the front of the radiator.

 

Btw the factory Oil pressure light only comes on when it's 2.1 PSI or less.. by that time the damage has been done, since I just lost my Ej25 not too long ago due to low oil pressure, I'm installing a oil pressure gauge.

[ivans imports]

Have 4 dead 2.5 d s from last week alone 3 headgaskets one thrown rod and 3 more calls today 2.5 headgasket over and over 95-98 twin cams why they go more in the cold a'm not sure.

[Deeron]

Ivan's imports:  Perhaps it's from people running their vehicles hard without warming them up first (something that I'm occasionally guilty of), which I'm told is especially bad when the block and head are made from different materials?  Or could the operation of the heater somehow effect the flow of coolant in some unintended way that causes headgasket failure?  

 

Based on your experience with these things, do you recommend repairing head gasket, replacing the engine or just scrapping the car?  It only has 134k. on it.      

[ivans imports]

change headgaskets as long as it runs ok And do a oil preshure check min 10 psi hot at idle The engines I see are all high kms 300000-400000kms Most headgaskets I do are at about 200000-300000kms

[Deeron]

So the mechanic here (a subaru dealer) told me that there's a 50% chance that there is also a cracked sleeve and that it probably isn't worth fixing with all the other problems.  The engine runs fine (besides the overheating issue) so are they just trying to get me to buy a new car, or is that really that common with these engines? 

[987687]

Of course a dealer is trying to get you to buy a new car, that's how they make their money.

They don't make money on old cars, nor do they really want to work on them.

 

I've only ever seen one 2.5 with a cracked sleeve. I beat the spoob out of it to the point it overheated and snapped a conrod, it kept driving for a few miles before total destruction....

This motor had a long history of violence...

Edited December 16, 2013 by 987687

[Deeron]

hmmmm.  That's one sleeve out of how many blown head gaskets?  I thought it sounded fishy especially when they told me that there is a 50% chance, because if that were the case then no one would repair head gaskets on these things.  If it passed  leakdown test with a warm motor would that mean that it's pretty unlikely to have a cracked sleeve, or would that not mean anything.  

Edited December 16, 2013 by Deeron

[987687]

If it was a cracked sleeve you'd have terrible noises, metal in the oil, coolant in the oil, bad leak down, blow by, and it probably would run like junk. HGs on these won't come up on a leakdown. But it's not a cracked something or other. That's BS.

[Deeron]

Thanks for the input.  I found an older post where someone in this same area had similar experience with a Subaru dealer here.  The dealer claimed it was a "cracked sleeve."  I called 3 other mechanics, all of who agreed with the folks in this site: the dealer is not being honest, if it runs fine, then it's most likely just a head gasket.  It's unfortunate that people practice business this way.  I guess it's time to take the car elsewhere.    

[ivans imports]

Never ever ever seen a cracked sleeve dosent happen heads don't crack [ Unless has been frozen ] I call bull on dealer they are just scared to take on the 2.5D happens lots this engine is a shop burner and very difficult to fix right. Run fast and far and find someone who has many Subaru headgaskets under there belt. For ex I have done over 100 headgaskets thiss year. and they keep coming On every single one customer was in headgasket denial Think I need a thermostat or rad { no you need headgaskets } over and over is always the last thing customer wants to hear but always the problem no point wasting money on anthing but. Anyway dealers are for servicing cars not fixing motors above there heads and abillitys.

[Paine]

Probably not the case for you but...

 

I overheated outside of Chicago 700 miles from home and 700 miles from where I was going. Freeway driving, out of nowhere, straight to the red line. I was 100 percent sure it was head gaskets. Turned out to be the 7 dollar radiator cap. Can't hurt to give it a try.

[ivans imports]

Don't let it fool you !

[subnz]

If doing all the previously suggested things ie headgaskets, correct genuine thermostat etc ( cheap ones don't open / flow well enough)

and still have problems need to consider the radiator especially  if it was 2nd hand it could be defective / partially blocked /  not flowing well enough also,  so get it flow tested by a radiator specialist if this is the case.  If blocked,   tanks will be required to be removed and the cores "rodded out"

Edited December 22, 2013 by subnz