Timing belts

[John Rethorst]

I bought an '01 OBW a month ago, with 36000 mi. on it. Very well kept-up,
appears near new. So I'm happy as a clam and then, just as I'm falling asleep
one night, I remember talking with my girlfriend's brother back in 1991 or so.
He had a Subie and the timing belt had just broken, requiring a new engine. May
I sleep with the assurance that Subaru definitely fixed that issue? Thanks,

 

[Edward Hayes]

Your 2.5L engine has a 105,000 miles replacement interval. Sleep well. ed

 

[John Rethorst]

Your 2.5L engine has a 105,000 miles replacement interval. Sleep well. ed

Thanks ed.

 

[RJ Walsh]

Breaking the timing belt, by itself, will not require a new engine but
if this occurs on a 2.5l with the "interference" valves then a valve
could strike a piston when the belt breaks thereby the need for engine
work. This was fixed in the newer years, not sure when, but I know my
`97 Legacy has the interference setup. Info on this has been in this
group before.

 

[uglymoney]

Thanks ed.

Correct. But it is still an interference design. If it breaks, it
interferes...

nate

 

[Jim]

Splitting this thread a bit, Have a '97 Legacy with the 2.2L engine.
My recollection is that this is a non-interference engine; correct?

 

[Edward Hayes]

Don't know about 2.2.L engines but, SOA says "ALL 2.5 L ENGINES ARE OF THE
INTERFERENCE TYPE" Ed Hayes

 

[Henry Paul]

I have a '96 Impreza with the same engine. The 2.2 is non-interference.

 

[pickle]

I have a '96 Impreza with the same engine. The 2.2 is non-interference.

It is my understanding that all of the Subbi 2.2's are of the
interfearence type. We all have opinions on this.
Perhaps we can find a site that puts this to rest.
Than we'll all know.
If I find anything, I'll post it here.

 

[Henry Paul]

I have the SOA service manual. Non-interference.

 

[Mickey]

Don't know about 2.2.L engines but, SOA says "ALL 2.5 L ENGINES ARE OF THE
INTERFERENCE TYPE" Ed Hayes

That's funny! Earlier this yr when I replaced the belt on my 00 SOC
2.5, I turned the cam shaft by hand with crank TDC and never felt any
interference. I think it is just the dual OHC 2.5 that are
interference designs.

Mickey

 

[Edward Hayes]

Mickey: The SOHC and DOHC 2.5L engines use the same valve angle and are
interference engines. It is not as simple as just turning the crankshaft or
camshaft. It is when both crankshaft and camshaft are spinning and one spins
down while the other is turning that the problem occurs. For instance when a
camshaft is out of step or stopped (broken belt), some intake and or exhaust
valves are open when the piston comes up and hits the valve. ed

 

[Henry Paul]

Is it possible then to have the camshaft move accidentally while replacing
the timing belt and not cause any damage?

 

[y_p_w]

Is it possible then to have the camshaft move accidentally while replacing
the timing belt and not cause any damage?

I don't think turning it by hand as slow speed is a problem. The
problem is when they collide at engine speeds. I tap two glass
bottles lightly, and nothing happens. Smash them into each other
at 25 MPH, and you end up with broken glass.

 

[John Rethorst]

The SOHC and DOHC 2.5L engines use the same valve angle and are
interference engines.

How can you tell which one (SOHC or DOHC) your 2001 OBW has? I've looked through:

http://www.cars101.com/outback2001.html
http://subaru.com/owners/
http://www.subaruoutback.org/
http://www.strictlycars.com/topsubarusites/index.html

and can't find when Subaru went from one to the other. I'm not big on
performance but (as a new owner of an '01) do want to know which engine I have
so I can look at its history and take a proactive stance towards maintenance.
Thanks,

 

[Henry Paul]

The head size and timing cover size give it away. The dealer can tell you as
well if you give them your VIN number.

 

[Edward Hayes]

Your 2001 is the SOHC version as is my 2000 Forester. The change over was in
1099 or 2000. As a double check whey not go to SOA at www.Subaru.com and
ask. ed

 

[Mickey]

Mickey: The SOHC and DOHC 2.5L engines use the same valve angle and are
interference engines. It is not as simple as just turning the crankshaft or
camshaft. It is when both crankshaft and camshaft are spinning and one spins
down while the other is turning that the problem occurs. For instance when a
camshaft is out of step or stopped (broken belt), some intake and or exhaust
valves are open when the piston comes up and hits the valve. ed

Not wanting to get in any argument but. The piston doesn't get any
higher than TDC as I had mentioned in original post. Rotating the cam
ALL valves in that head have a chance to open and hit anything they
interfere with. Now on the DOHC engine if the cam belt breaks, it is
possible for both the intake and exhaust valves to be open at one
time. Not sure if the interference design is valve to valve or valve
to piston issue.

Mickey

 

[Edward Hayes]

Mickey: I email SOA technical dept and they said ALL 2.5L Subaru engines are
of the interference type. ed

 

[Jim Stewart]

Not wanting to get in any argument but. The piston doesn't get any
higher than TDC as I had mentioned in original post. Rotating the cam
ALL valves in that head have a chance to open and hit anything they
interfere with. Now on the DOHC engine if the cam belt breaks, it is
possible for both the intake and exhaust valves to be open at one time.
Not sure if the interference design is valve to valve or valve to piston
issue.

Looking at the illustration in the maintainance manual,
I suspect both.