Unpredictable overheating

[ccridge]

My 1998 Subaru Legacy [76,000 miles] started randomly over heating last
year. The radiator was removed and cleaned and the thermostat replaced.
For six months no problem then suddenly yesterday the engine heat gauge on
the dash goes to the max temp. Meanwhile the cabin heater is blowing
unheated air. If the past is any indication, the problem will go away for
a week or a month and then reoccure again. It's almost like some loose
foreign matter is floating in the coolant and suddenly blocks a key
passage. I'd appreciate any help.

Thanks
Chris

 

[George Adams]

From: "ccridge"

For six months no problem then suddenly yesterday the engine heat gauge on
the dash goes to the max temp. Meanwhile the cabin heater is blowing
unheated air.

Sounds like a head gasket. Get it checked out before serious damage occurs.


George Adams

"All good fishermen stay young until they die, for fishing is the only dream of
youth that doth not grow stale with age."
---- J.W Muller

 

[Bob Bailin]

My 1998 Subaru Legacy [76,000 miles] started randomly over heating last
year. The radiator was removed and cleaned and the thermostat replaced.
For six months no problem then suddenly yesterday the engine heat gauge on
the dash goes to the max temp. Meanwhile the cabin heater is blowing
unheated air. If the past is any indication, the problem will go away for
a week or a month and then reoccure again. It's almost like some loose
foreign matter is floating in the coolant and suddenly blocks a key
passage. I'd appreciate any help.

It sounds like you have a slow coolant leak, possibly from a leaking
head gasket that's also allowing exhaust gases into the coolant,
displacing even more coolant.

Check the coolant level in the radiator when the engine is cold. It
should be completely full, and probably isn't. The coolant overflow
bottle is probably almost empty, too.

Bob

 

[Jim Stewart]

My 1998 Subaru Legacy [76,000 miles] started randomly over heating last
year. The radiator was removed and cleaned and the thermostat replaced.
For six months no problem then suddenly yesterday the engine heat gauge on
the dash goes to the max temp. Meanwhile the cabin heater is blowing
unheated air. If the past is any indication, the problem will go away for
a week or a month and then reoccure again. It's almost like some loose
foreign matter is floating in the coolant and suddenly blocks a key
passage. I'd appreciate any help.

It sounds like you have a slow coolant leak, possibly from a leaking
head gasket that's also allowing exhaust gases into the coolant,
displacing even more coolant.

Check the coolant level in the radiator when the engine is cold. It
should be completely full, and probably isn't. The coolant overflow
bottle is probably almost empty, too.

Agreed. The lack of cabin heat is a dead
giveaway that there's no coolant in at least
part of the system.

So you have 2 problems. The first is getting
the air out of the cooling system. The second
is finding out what caused the problem in the
first place. Bob's theory sounds likely to me.

 

[WillM]

Head gasket would be my guess. My 98 Outback did the very same thing last
winter. Although, it was not as random as you are experiencing. These
engines are notorious for blowing head gaskets.

Will

 

[Mike]

My 1998 Subaru Legacy [76,000 miles] started randomly over heating
last year. The radiator was removed and cleaned and the thermostat
replaced. For six months no problem then suddenly yesterday the engine
heat gauge on the dash goes to the max temp. Meanwhile the cabin
heater is blowing unheated air. If the past is any indication, the
problem will go away for a week or a month and then reoccure again.
It's almost like some loose foreign matter is floating in the coolant
and suddenly blocks a key passage. I'd appreciate any help.

Thanks
Chris

Two words... HEAD GASKET

I had my 1998 Subaru Outback begin to have random and sudden overheating
episodes at about 88,000 miles. I checked the thermostat and purged air
out of the system. A telltale sign is that when you see air bubbles
(exhaust gas) coming from the overflow tube in the coolant bottle.

 

[hippo]

All the previous comments sound fair enough. If the cold coolant level in
the radiator and header tank checks out ok, check if the bottom hose has
collapsed or is really squishy once the car is warmed up - but before it
boils! Cheers

 

[Dr. Rastis Fafoofnik]

I have a 98 Ltd Edition Liberty here in Aus. 76,000 on the clock, the exact
same symptoms that you are experiencing. They didnt pick it up the first
time. Now it is back in the shop. No 3 Cylnder has a broken head gasket.

I thought that the boxer engine was renowned for its relibility. cant
beilieve that i only got 76K out of the thing before i have to spend 2K
having the thing rebuilt. I am a little pissed! Wont be so quick to buy
subaru again!

You know..it's funny...I call out problems like this with subaru(and other
POORLY designed autos) and the people that own them get SO PISSED OFF.
They dont want to hear/see this info printed in public.
While the WRX series may be a tad faster than other imports, SUBARU's wont
last for the long run!
75,000 miles(or 4 years) and they are falling apart! Toyota/Honda and most
american iron last FAR longer than that.
Subaru is a cheap car, built cheap, to be cheap.Built with a dollar sign in
mind.

 

[Gavilan]

I have a 98 Ltd Edition Liberty here in Aus. 76,000 on the clock, the exact
same symptoms that you are experiencing. They didnt pick it up the first
time. Now it is back in the shop. No 3 Cylnder has a broken head gasket.

I thought that the boxer engine was renowned for its relibility. cant
beilieve that i only got 76K out of the thing before i have to spend 2K
having the thing rebuilt. I am a little pissed! Wont be so quick to buy
subaru again!

Head gasket would be my guess. My 98 Outback did the very same thing last
winter. Although, it was not as random as you are experiencing. These
engines are notorious for blowing head gaskets.

Will

My 1998 Subaru Legacy [76,000 miles] started randomly over heating last
year. The radiator was removed and cleaned and the thermostat replaced.
For six months no problem then suddenly yesterday the engine heat gauge
on
the dash goes to the max temp. Meanwhile the cabin heater is blowing
unheated air. If the past is any indication, the problem will go away for
a week or a month and then reoccure again. It's almost like some loose
foreign matter is floating in the coolant and suddenly blocks a key
passage. I'd appreciate any help.

Thanks
Chris

 

[hippo]

<<You know..it's funny...I call out problems like this with subaru(and
other POORLY designed autos) and the people that own them get SO PISSED
OFF. They dont want to hear/see this info printed in public.
While the WRX series may be a tad faster than other imports, SUBARU's wont
last for the long run!
75,000 miles(or 4 years) and they are falling apart! Toyota/Honda and most
american iron last FAR longer than that. Subaru is a cheap car, built
cheap, to be cheap.Built with a dollar sign in mind.>>

You know, I keep reading your posts and wonder if we're dicussing the same
brand? Obviously everyone believes what they believe, but just consider
this. My 13yo Liberty (yr Legacy) wagon was recently traded with 332000Km
(just over 200K miles) roadworthy, rust and probelm free, with routine
maintenance over the 6 years I had it and my 99 OB
Limited does everything expected of it. Friends & acquaintances have 40-45
different brands of car, ranging from the very old and questionable to
brand new BMW, Merc, Subaru, Toyota, Lexus, MG, Ford, Holden (yr
Chev/Pontiac) and most of the current Japanese & Korean ranges. Most rate
Subaru highly, many will buy another one.... and no, they're not all rich
&/or running lease cars with pre-paid maintenance either. Cheers