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Mallory

2003 Forester using oil and anti-freeze, what to look for?

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I have a 2003 Forester that my daughter has been driving for a couple of years.  It has 160,000 miles on it.  It is either using or leaking oil and also either using or leaking anti-freeze.  Both are slow enough that there's never any sign on it leaking on the ground, even if I leave it parked and idling for a long time.  I haven't gotten into this project yet, but I'm looking for ideas as to what I should be checking.  I'm pretty sure it still has the original cam belt, and I will be changing that and the water pump very soon.  I'm hoping the water pump is the source of my anti-freeze leak.  What are some common leaks on these cars that I should be looking at?  Thanks.

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Head gaskets, especially if it’s the EJ25. Although I’m not 100% sure the factory head gasket leak runs into the EJ253 which I believe your forester has.

@GeneralDisorder - he’ll be able to give you the required head gasket part number to correct the leaks. 

How much oil and coolant is missing and over what time period are we talking?

Cheers 

Bennie

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Try these 2 easy fixes before assuming that it's a head-gasket leak:

- Tighten all clamps on the coolant-hoses (if they are adjustable).

- Install a new (Subaru OEM) PCV (Positive Crankcase Ventilation) valve.

On the EJ25 engine, the head-gasket typically leaks oil and/or coolant to the exterior of the engine.  And the favored spot to see this leak is on the left-side (driver's side in US) head, near the rear of the engine and underneath.  You have to get underneath the car. You're looking for the joint between the block and the head (not the joint between the head and the rocker-cover, although that might also leak). If the head-gasket is leaking, you'll see oil seeping out of that joint. If the oil-consumption is manageable, replacing the head-gasket is not urgent (but still desirable).

Edited by forester2002s
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Inspect for leaks.  Look carefully under the engine. 

Oil loss - external visible leaks or install a Subaru PCV or it’s blowing past the rings  

Factory installed 03s usually leak coolant externally.  They start leaking very slowly at first underneath and progress slowly over a long time.  You can drive them a long time (I’ve seen 100k+) by simply topping off fluids. 

Already replaced head gaskets (not at all unlikely) are less forgiving and have more varied failure modes. 

If it’s an external leak the Subaru coolant conditioner works almost 100% of the time on initial external coolant leaks of original factory head gaskets  

If original that belt is insanely overdue by age and miles. 

Install AISIN or Subaru timing kit - belt and all pulleys and tensioner and water pump.  At a minimum at least replace the belt and lower toothed idler, the most common timing failure points. 

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El freddo - I have no idea on how much oil or anti-freeze it's using.  I haven't driven it and my daughter wasn't the best at keeping track.  That's why I wanted to know the main problem areas to look at first so I don't find them the hard way!

My buddy has a shop and we're going to put it up on the lift and look it over close for leaks.  From the posts I've read so far I'm thinking it will probably need head gaskets.

What is the cam belt change interval on these cars?

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105,000 miles 105 months.  If it's original and needs head gaskets do it all.  Buy an Aisin kit instead of cheap Chinese Junk Gates or Dayco

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How can I tell which engine my car has?  All I know for sure is it's a 2.5 liter single cam.  Does that make it an EJ25?  Is there a tag or is it stamped on the engine somewhere so I can tell for sure?

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12 hours ago, Mallory said:

How can I tell which engine my car has?  All I know for sure is it's a 2.5 liter single cam.  Does that make it an EJ25?  Is there a tag or is it stamped on the engine somewhere so I can tell for sure?

Its an EJ25.  Nothing else non-turbo ever came in any 2000’s Forster. 

Resurface the heads (GD has a thread on here for DIY, really easy), install Subaru headgaskets and follow bolt and torque procedures precisely.   Check valve clearance   

Install AISIN timing kit

timing belt interval is 105 months or 105,000 miles. 

But at this age and miles the pulleys are not generally wise to leave in place. They should be replaced as well. If they fail then the new belt breaks and being an interfernce engine the valves bend, usually a lot of them.  

The kit is actually cheap for high quality and getting a reliable 100,000, no surprises, miles out of it.  

New plugs, wires, and PCV valve and it won’t really need anything but oil and air filters for 100k. 

Edited by idosubaru

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Every Aisin kit I find says it's only for manual transmission cars, and mine is an automatic.  Is there a difference in belt kits?  I don't see why there would be.  I don't find any other kits listed that way, but I don't dare order without knowing for sure.

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I believe the difference between the MT and AT kits is the water pump outlet.  The manual kits also include a spacer for setting the gap on the timing belt guide only used on the MT vehicles.  I believe the auto water pump has an extra outlet, but I may not be remembering it correctly,

 

Edited by Mike104

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