2004 Forester Timing Belt

factor of 10+ difference in cost doing it vs waiting til it breaks.

do it, and don't cheap out - change the water pump, idler bearing ,tensioner - basically everything that turns except cams/ crank.

I had mine done a couple of weeks ago when I needed a new water pump. Nowhere near mileage but when pump was off, only extra cost was the belt as it was put on a new one or put back the old one.

You'll be more than stranded when the belt breaks and the valves collide into the pistons.

Do you have a crystal ball?

I'd strongly suggest changing the belt for several reasons. First, I believe they may have advertised a 105k interval, but I think on some models they rethought that and went back to 60k?

As someone who had a timing belt break on a Honda, you don't wanna go there just to save a few hundred bucks in preventive maintenance.

Second, Subarus like Hondas are interference engines. If your belt breaks, you'll not just be stranded, you'll have enough engine damaage such that you'd have essentially just totalled your perfectly good

2004 car.

Finally, have someone that knows subes do this job. A non-sube savvy generlist is quite likely to f*ck it up, at least in my experience with an independent mechanic.

Thank you all for the advice, I will take it to the dealer for the service.

Oh...one last bit of advice, it's a sales recession and dealers are looking to make up the revenue in the service department. Don't be surprised at a lot of suggested services, like the oh so lucrative fluid power flushing services that come in transmission, brake, engine oil, and differential varieties. All of them costing around $139 each. If you can check and eyeball those fluids and know when last you had them serviced going in, you'll be in a better spot to know whether the "your fluids are FILTHY!" FUD you'll likely get is legitimate or not. If you haven't had any of these done lately, though, they probably are worth thinking about though as the service interval on a lot of the fluids is a lot more frequent than a lot of people realize.

I'd be interested in the list's collective opinion of these power flush services and whether they're really worth the benefit they advertise vs drain and fill, and whether there aren't reliably just-as good places to have it done outside of a dealer. Refilling coolant on Subes does seem to be trickier than most other cars, so there may be an argument for having that done with a sube savvy place? I'm curious.

Dave--as for less specious upsells you might face: when doing a timing belt, it's usually advised to change the water pump since it's not that much of an adder to the job, and if the water pump takes a shit, you're stranded, engine overheats, and would have to re-do all the labor of getting that timing belt in there (and be stranded) anyway. Timing belt tensioners on the 2.5L cars are like disposable candy too, so it's possible that they'll suggest a new "cold weather 2 minute ticking device" (aka the timing belt tensioner) with the timing belt service too.

Good luck!

Firmly believe replacing the ATF/filter and the coolant at recommended intervals is money well spent if you are the type that drives the car to its end of life. I once got 450K miles out of an old Chrysler by adhering to this.

Someone please explain the advantages of interference engines. Subaru used to have many (most?) non-interference engines and now, seemingly, has none. What gives?

Thanks,

Dima

All manufacturers are chasing better economy/emissions/power optimization and I doubt there are many non-interference belted 4cyl. engines around. I think Toyota may still have one. Subaru's flat 6 engine has a chain that should last the life of the engine. I think mazda has an inline 4 with a chain. Perhpas there is a trend toward chains now.

Maybe someone else has more info.

The advantage of an interference engine is that they can make it with a higher compression ratio more easily. Try to design an engine with

10.5 to 1 compression without interfering. It might be possible, but you'd have to angle the valves so they would be more parallel to the travel of the piston. This would crowd room for spark plugs and would create a need to make the flow into and out of the chamber more in line with the travel of the piston as oposed to swirling around the chamber. That swirl allows the flow to not have to slow as much and steals less energy from the flow, thereby increasing efficiency. There are many many reasons for valve angles to be as they are.

So you can have either good flow efficiency, a high compression ratio, or a non-interference engine, or any two of them, but probably not all three.

I have a 1995 is that non interference?

Jeff typed -

According to Google, which you could certainly have done, it is a non- interference, whether it is a 1.8 or 2.2, since you didn't say. But you should still change the timing belt at recommended intervals.

Dan D '99 Impreza 2.5 RS (son's, currently undergoing cosmetic surgery) Central NJ USA

The 1.8 ansd 2.2 are non-interference, and the 2.5 is interference. I have heard that the 2.0 is non-interference, but the same person that said that said,"it's gotta be since turbos have such low compression." That makes sense, but it's not the same as knowing for sure that it is.

I jsut did a timing belt on my 2.2 a few months ago and I can confirm that you can turn the cams round and round without smacking the piston. Or at least I coudl with the particular position that my pistons were in at the time, which might not actually mean much.

Have a good one, Bill

Yeah, there IS a soob engine that will not collide piston to valve, but the VALVES will collide with each other due to angle/diameter geometry.

As in the exhaust valves will collide with the intake vavles? That must be a DOHC engine since it isn't possible for one cam to open both valves on a cylinder at the same time. I think the only DOHC engines are the early 2.5s and the 2.0s, so since the 2.5s are already interference with the piston, maybe that is the 2.0 engine. I'm just thinking out loud. Not saying it is so. Any insight on this?

Bill

I THINK it's the later 2.2s (after 96) that can do that. Not sure.

here's some data (there's the 2.5 SOHC listed that I have doubts about being non-int at one of the links so , YMMV)

list of Soob engines;

also from; ******The SOHC EJ Subaru boxer engines were non-interference enginesthrough 1996, run by a single timing belt driving both cams (bothsides of the engine) and the water pump. Because they are non-interference engines, if the timing belt fails, the engine of themodels up to 1996 will not be destroyed. The oil pump is drivendirectly from the crank shaft and the waterpump by the timing belt.All DOHC and 1997-up SOHC EJ engines are interference engines, if thetiming belt fails the engine will likely be destroyed or the valves &piston will be heavily damaged.****** Interestingly, the DOHC EG33 flat 6 'likely' could never suffer interference if 'only' the timing belt broke because of the gear driven second cam.