Timing belt and water pump change?

[jseabolt]

Got a few questions regarding timing belt changes. First all is the 2.5 liter engines used in the Bajas an interference engine?

 

This website says some Subaru 2.5 liter engines are DOHC and some are SOHC.

 

http://autorepair.about.com/od/glossary/ss/timin-belt-inf2_6.htm

 

I figured all Boxer engines were DOHC wheather is be Porsche, Subaru, etc. That would be a given. Also I've never heard of a 2.7 liter Subaru engine. I know there is a 2.0 , 2.5 and a 6 cyliner.

 

That leads me to believe this website is not correct on anything.

 

Next question. My Baja has 61K miles on it so is it time to change the timing belt?

 

I've changed timing belts before on old Fiats and it's pretty straight forward so because there is plenty of room to work and nothing major to remove, I plan on doing it myself.

 

The next question is some "kits" on Ebay include a water pump as well. I know the importance of changing the tensioner bearing (I suppose Subaru has three of them) but is it nessessary to change the waterpump everytime you do a belt change?

 

I realize if the water pump fails you'll have to change the belt anyway because it's driven off the timing belt but what is the life span of a Subaru waterpump? Or is this one of those deals, "While your down there...."

 

I thought about just changing the waterpump at the next belt change. Any change the waterpump will make it to 120,000 miles? What is the typical life span of a Subaru waterpump?

 

On the other hand I've had cases where I've replaced a 15 year old "good" part with a newer part just because they were old (e.g. Fiat driveshaft couplings) only to have the new part fail in 5 years because most of the replacement parts for Fiats are substandard because they come from Russia or Turkey or plants in Italy with no quality control.

 

Also had issues with my Jeep Wrangler where I'd get a recall on a part and they would replace it with a so called better part only to have it fail (cat converter).

 

Just wanted some opinions from Subaru mechanics if changing the waterpump at 60,000 miles is a crap shoot or a worth while thing.

[GeneralDisorder]

Got a few questions regarding timing belt changes. First all is the 2.5 liter engines used in the Bajas an interference engine?

 

This website says some Subaru 2.5 liter engines are DOHC and some are SOHC.

 

http://autorepair.about.com/od/glossary/ss/timin-belt-inf2_6.htm

 

I figured all Boxer engines were DOHC wheather is be Porsche, Subaru, etc. That would be a given. Also I've never heard of a 2.7 liter Subaru engine. I know there is a 2.0 , 2.5 and a 6 cyliner.

 

Your Baja engine is SOHC (unless it's a turbo).

 

The 2.7 is the ER27 - it came in the 88/89/91 XT6 and is based on the EA82 but with two more cylinders.

 

As far as engines - here in the US we have had: 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.5, 2.7, 3.0, 3.3, and 3.5

 

That leads me to believe this website is not correct on anything.

 

I haven't looked but it sounds like they aren't too far off.....

 

Next question. My Baja has 61K miles on it so is it time to change the timing belt?

 

No - 105k is the interval for your engine.

 

I've changed timing belts before on old Fiats and it's pretty straight forward so because there is plenty of room to work and nothing major to remove, I plan on doing it myself.

 

The next question is some "kits" on Ebay include a water pump as well. I know the importance of changing the tensioner bearing (I suppose Subaru has three of them) but is it nessessary to change the waterpump everytime you do a belt change?

 

With the 105k car - my opinion is a definite YES. Do you really want to take the factory water pump to 210k?!? On the older 60k belt cars I say every other belt.

 

I realize if the water pump fails you'll have to change the belt anyway because it's driven off the timing belt but what is the life span of a Subaru waterpump? Or is this one of those deals, "While your down there...."

 

Yep - for $65 I'm not going to skip it.....

 

I thought about just changing the waterpump at the next belt change. Any change the waterpump will make it to 120,000 miles? What is the typical life span of a Subaru waterpump?

 

Change both at 105k. I've seen factory water pumps seize at 130k. There's too many factors to estimate it but 100k to 120k is a good safe run for a WP.

 

On the other hand I've had cases where I've replaced a 15 year old "good" part with a newer part just because they were old (e.g. Fiat driveshaft couplings) only to have the new part fail in 5 years because most of the replacement parts for Fiats are substandard because they come from Russia or Turkey or plants in Italy with no quality control.

 

This is not a Fiat. Quality replacement parts are availible - for water pumps on Subaru's both Aisin and Paraut make OEM quality pumps.

 

Also had issues with my Jeep Wrangler where I'd get a recall on a part and they would replace it with a so called better part only to have it fail (cat converter).

 

It's not a jeep either. Around here we all use the ebay belt kits (theimportexperts, or mizumoauto are my favorite sellers) without any problems. The rule is that if you use the aftermarket kits - replace everthing EVERY TIME. They are cheap enough that it's just good insurance.

 

Just wanted some opinions from Subaru mechanics if changing the waterpump at 60,000 miles is a crap shoot or a worth while thing.

 

Subaru belts haven't been spec'd to 60k in well over a decade. It's been 105k since the late 90's. This should be in your owners manual....

 

GD

Edited October 18, 2010 by GeneralDisorder

[idosubaru]

you should tell us the year to distinguish between SOHC and DOHC and what phase you'd have - but a baja has to be a SOHC Phase II EJ25 if it's a non-turbo.

 

timing belt interval should be 105,000 miles, look in the owners manual. if you don't have one, get one. i'd wait until 105,000 miles or 10 years (or whatever year stipultaion subaru uses) to replace it.

 

cars101.com is fantastic subaru site with lots of info on your baja.

 

2.7 liter was a 6 cylinder engine in the 1989-1991 XT6.

[jseabolt]

I didn't know the timing belt interval changes were listed in the owner's manual. Sorry about that. I was just curious and Googled it while working the night shift.

 

Yeah my Baja is the non-turbo 2003 model. I think the door stickers says it was built in July or August of 2002 so it's probably one of the first ones to roll off the assembly line. If that matters.

 

I did not know that the turbo models were DOHCs. I thought it was just a bullet proof version of the same 2.5 liter that was in my Baja.

 

Actually I thought Subaru was only using three engines during that period. 2.0 liter in the Impreza, 2.5 liter in the Legacy, Baja and Forester, and the 6 cylinder in the Outbacks and Foresters.

 

Well since my belt doesn't need to be changed until 105K miles, I see no reason not to change the water pump as well. I just figured 60K miles was a bit early for a water pump. That's why I asked if they were prone to failure around 60K miles.

 

That's all I need to know. Thanks.

Edited October 18, 2010 by jseabolt

[OB99W]

Got a few questions regarding timing belt changes. First all is the 2.5 liter engines used in the Bajas an interference engine?[...]

Since I didn't see an answer to that question -- all Subaru 2.5 liter engines are interference, both DOHC and SOHC.

[Fairtax4me]

SOHC means one cam per head. DOHC implies 2 cams per head.

There are also plenty of boxer engines (old Porsche and VW) that are pushrod type.

Edited October 18, 2010 by Fairtax4me

[jseabolt]

SOHC means one cam per head. DOHC implies 2 cams per head.

 

Yeah I know the difference between a DOHC and SOHC engine.

 

I did not know there was 2 variations in 2.5 liter Subaru engines...

 

This is the first Subaru I've ever owned so please forgive me.