High mileage maintenance/wear items?

[DumpsterSoap]

Hey all, I have an 05 GT wagon with the 5MT that has around 170k miles with the original engine/trans.  Car is mechanically stock, only real modification is a catback exhaust.  I'm wondering what maintenance items to look for and just items in general that like to go out at higher miles.  I have done a good bit of maintenance on it already (as well as catching up on some other things still) - I'm not a car expert by any means, but I'm fairly mechanically inclined and have a good idea of what to look for.

Some of the items I've done in my past two years of ownership are the oil cooler gasket (along with the connected hoses and coolant crossover pipe), passenger side rear brake line, new battery, new engine and cabin air filters, turbo banjo bolt filter removal, starter, and power steering pump o-ring.

I'm also in the middle of doing the spark plugs but the threads on cylinder 3 stripped out, which I suspect is from the spark plug being cross-threaded when it was last replaced.  I don't have the garage space to pull the engine to properly fix it, so I'm most likely taking it to a trusted Subaru shop to fix.  While they do that, I think I'm going to ask to do the headgaskets at the same time for the peace of mind.  I do have some parts/fluids which have to go in the car yet but haven't gotten around to, such as gear oil for both diffs and the transmission, front O2 sensor, and exterior weather stripping for the rear windows.  Valve cover gaskets were done a few years ago and planning on doing a timing belt job in the next 5-10k miles.

With that being said, is there anything specific I should look for with such high mileage?  Motor mounts look fine to me (no fluid leaking/rubber looks okay) but some of the suspension bushings have seen better days.  I've also heard the hoses for the PCV system should probably be looked at to make sure the rubber looks okay.  I haven't checked wheel bearings yet but it is also on the list to inspect.  Open to any suggestions/comments.

[BoozeRS05]

Depending on location and condition of the car, I don't REALLY know whether I'd go after the headgaskets if they aren't troubling you.  I'd probably stop at the valve covers, oil pan and rear main seal.  Definitely suggest getting a new PCV assembly (it's an assembly, not just the valve) to install while the motor is out.  Look over all the hoses in there with this age and those miles.  I'd jump on new motor mounts though, 170k is a lot of miles on the OE mounts in my mind.  The coilpacks can get pretty crusty too, only use OEM.  Clutch and flywheel resurface depending on how old they are now.  New motor ground wires.  If you have the OE turbo still in there, I'd probably want to have one of those ready.

Fwiw, I don't trust the manufacturer's tune.  On a stock car I feel like a COBB stg1 map is significantly healthier than the factory tune.  My $0.02

[Max Capacity]

I would not worry about HG's as turbo motors don't have the same issue as NA engines.

If it ain't leaking, leave it alone.

Check the under engine ground straps, you can make up your own ground wires that will out last OEM.

The PCV from NAPA is like $14.00

I'll say NGK coils are good too, only use NGK plugs. 

Denzo 234-9120 is the only Front O2 sensor to use.

[All_talk]

I'll add...

 

As you noted, wheel bearings, specially the rear.

Keep an eye on the coolant temp, sooner or later it will need a radiator. 

And if you have the engine out inspect the turbo oil drain line. They can get hard and weepy, and are much easier to change with the turbo/engine out.

[DumpsterSoap]

The only reason I brought up maybe doing head gaskets is I kept seeing air bubbles when trying to burp the coolant last year.  Granted, it was also my first time doing a coolant flush, so could be just inexperience.  But I didn't see any temps above the standard operating temperature, so HGs came to mind.  I haven't done any additional testing to confirm this, but coolant levels have been fine and oil looks normal.

Ground straps are good, that is one other thing I did remedy.  All parts gone into it are OEM - spark plugs, O2 sensor, etc. etc.  The coil packs do look a little worse for wear, so I've made a note to replace those in the next year or so.  I'll definitely make a note to get the rear main seal replaced while it's out, as well as a couple other things you guys have mentioned.  As I've found out before, "while you're in there" is a dangerous phrase!!

The turbo was replaced at one point (I can't remember when/what mileage without looking at the records), but it's been holding strong.  Clutch is pretty fresh and still grabs great.  One other thing I was looking into doing eventually is new belts/pulleys, especially with the separation issue the crank pulley likes to present.

Thanks for the responses, definitely appreciate the info!  Love this forum!

[Max Capacity]

What's the build date ? it should be on the driver's door jamb label. 

I replaced heater hoses May 2012 when I put a ej257 short block in.  

 

I replaced my oil pan and coolant cross over tube (2nd time), I filled the coolant system while the front end was high in the air. Slowly filled the radiator, I could hear burping in the tank while slowly filling. Left an inch or so low in the turbo tank. I put rad cap on, lowered the left side a bit, keeping right side higher. Started engine, let T'stat open. level in tank didn't really change. I shut off engine, lowered car, put cap on tank. Added a small amount to overflow tank. Took car for test ride, shut off engine. Looked in overflow tank saw couple of bubbles as coolant returned to radiator system. Car did not and has not gone above the 9 o'clock on temp gauge. I've put almost 200 miles on, no issues. I have added a small amount to the overflow tank the second day. I use a thin wood stick to put down the bottle to check level.

[Max Capacity]

Have you seen that link ?

[DumpsterSoap]

I have!  I'm 1 of 86 - RBP 5MT Limited wagon.  I'll see if I can find some pics to post.  Definitely doesn't look like it has as many miles as it does, and is surprisingly clean rust-wise despite being a midwest car all its life.  Needs a good paint correction, which I plan on doing once I get the space.

[BoozeRS05]

Same as mine! They only made our color one year, glad to see you’re taking care of it 

[DumpsterSoap]

Nice, matching black interior too!  I didn't know they made RBP for only one year, that's an interesting fact.  It is a fantastic color, although I'd be lying if I said I wouldn't swap it for a GRP wagon if I had the chance haha.  But the way it shines in the sun is something else.  My main goal is to get the car up to speed with everything previous owners neglected and get it to a good spot.  Slowly but surely.

[Pleides]

The stuff that goes with high mileage on any car is rubber, so replace any and all suspension bushings. The factory ones are quite soft on our cars and don't usually go much beyond 100K and 10 years. All of mine are no longer original in every suspension arm as well as the sway bars. 

The HVAC actuators tend to go. Sit on both sides of the car with the heat on as well as with the A/C on the manually at 65 with the fan all the way up and see if both are roughly the same temperature. The passenger footwell one that controls temperature often breaks and is a relatively easy fix. It sounds like a bubbling coffee machine when it dies. Mine got stuck in the full-cold passenger position.

Window seals tend to go. They're becoming a rarity, so buy them now if you need them.

Everything else is fix as you go. I popped my first engine at 214K and am at 235 now. 

Don't do the head gaskets for now. If your engine ever goes for any other reason (which is much more likely in the form of piston ring or rod bearing failure, perhaps a burnt valve within your heads if you're unlucky) then they'll need doing anyways. They tend to last on the turbo cars as long as the boost stays at 20 PSI or under on more factory-size turbos. Larger turbos and higher boost will necessitate head studs from ARP.

 

You mentioned it's a midwest car. The fuel filler neck is likely rusty if there's even a spec of rust underneath the car.

[KZJonny]

Just because you’ve already opened your wallet…. I’ll mention it’s worth looking at fuel tank seams as well. I’ve seen quite a few 05-06 vintage cars now, and most seem to have had the tank replaced, or are rusty to the point of near failure. (This is the time to replace all evap hoses while you’re in there….) maybe you are lucky and it’s all good.

Most of the rest seems to have been covered… I’ll note that I took someones advice and replaced the crank pulley with a Fluidampr unit. Spendy yes, but it does seem to tamp down vibration and add a some extra smoothness to deacelleration in particular and low RPM shifting.

[DumpsterSoap]

Thanks for the responses.  After I take care of the current projects, the plan is to take a good look underneath and see what needs to be taken care of - suspension, bushings, etc.  Good advice on the fuel tank area, I'll make sure to look at that.

I've heard good things about Fluidampr and going that route for a crank pulley.  I've not done much digging on it yet, but is there a reason why those are generally recommended over single piece crank pulleys instead?  Such as the Grimmspeed or Perrin units.

[KZJonny]

11 minutes ago, DumpsterSoap said:

 

I've heard good things about Fluidampr and going that route for a crank pulley.  I've not done much digging on it yet, but is there a reason why those are generally recommended over single piece crank pulleys instead?  Such as the Grimmspeed or Perrin units.

Fluidampr is silicon filled, so it is using a variably viscous fluid damper as the name implies. It's a little like the VLSD in your rear differential, the harder you push on it, the thicker the silicon gets as it resists shear.

It's much closer to the idea of the "added weight" flywheels like GADT offers:

https://shop.getadomtune.com/light-enough-crank-pulley/

This could be a very long and technical answer, but I suppose it can be summarized like this:

-light cranks can help a little with hitting target RPMs faster because you are accelerating less rotational mass. So, quicker into boost, etc... They are typically incompatible with a lightened flywheel if you are going that route... So, one or the other. Too little rotational mass causes problems, balance and vibrations issues.
-because they are typically just a hunk of aluminium with no type of dampener in them, they can be quite cheap
-they have disadvantage as well, like RPM drops off more rapidly between shifts, again, because you have less momentum keep the engine spinning when you disengage the clutch, and many report chattery clutch engagement and "juddering/jumping" getting going from a stop....ymmv

 

Heavier crank pulleys do kind of the opposite.

-slightly slow down RPM rise, and hold RPM a little better between shifts
-compatible, or perhaps even complimentary to a lighter flywheel, if playing with those variables is a thing you want to do.
-in the case of the Fluidampr, cost is a factor, since it a multi part design, etc... however, the fluid dampening is (in my experience so far) actually noticeable, and I find idle a little smoother, and I can definitely take my time a little more between shifts, which I like. Hard for me to pin down how much the thing did just on it's own, since I made quite a few changes at the same time (shifter bushings, Group N trans mount, etc...) But I do kinda have to say it is at least doing some of what is claims to.

I use my car more as a Grand Tourer, with some hard pulls down highway on ramps and jaunts down twisty roads at mid-speeds, so the setup suits me well. I suppose if I was looking for all out fast shifting and getting into boost as fast as possible, then a lightweight system would be better? Dunno. The JMP Custom VF40 I've got installed spools plenty fast enough that I have no problem getting into the meat of my peak torque range in a hurry.

Maybe that helps? It is some words anyway.

[DumpsterSoap]

That makes perfect sense, thank you for the explanation!  I agree in that a Fluidampr pulley would be the way to go - I do not mind paying more for a product if it does its job exceedingly well.  It quite honestly it suits these cars well, they are a Grand Tourer after all, right? 

I'll probably keep the power stock on this until the block keels over, in which I'll do some light power additions.  Certainly not aiming for a high speed/performance build by any stretch - that's what my 400whp turbo FRS is for anyway

[Pleides]

1 hour ago, DumpsterSoap said:

Thanks for the responses.  After I take care of the current projects, the plan is to take a good look underneath and see what needs to be taken care of - suspension, bushings, etc.  Good advice on the fuel tank area, I'll make sure to look at that.

I've heard good things about Fluidampr and going that route for a crank pulley.  I've not done much digging on it yet, but is there a reason why those are generally recommended over single piece crank pulleys instead?  Such as the Grimmspeed or Perrin units.

I asked my tuner at Surgeline about Fluidampr crank pulleys and he said they're an absolute must have at the 600 WHP+ mark just to keep the engine in balance and increase its longevity, let alone for how much better the car feels with them. I've never been in a car with one but it's on my shortlist just to quiet down the crank and engine movement.

[Infosecdad]

8 hours ago, Pleides said:

I asked my tuner at Surgeline about Fluidampr crank pulleys and he said they're an absolute must have at the 600 WHP+ mark just to keep the engine in balance and increase its longevity, let alone for how much better the car feels with them. I've never been in a car with one but it's on my shortlist just to quiet down the crank and engine movement.

I have one on mine with approx 300hp to the wheels and it’s a noticeable improvement in smoothing out the engine. Highly recommend if you can afford it. 

[DumpsterSoap]

I am definitely adding a Fluidampr pulley to the parts list.  Seems like a great addition and helps keep the same spirit a touring wagon should have IMO.

[KZJonny]

55 minutes ago, DumpsterSoap said:

I am definitely adding a Fluidampr pulley to the parts list.  Seems like a great addition and helps keep the same spirit a touring wagon should have IMO.

Disclaimer: I do not make any money from promoting them. Ha!

But I'll always put in a good word for a product that is well made, and does what it claims to do. I'm very happy with the how much smoother my engine is after the install, and since I really only finished my power and driveline related work a few weeks ago, it's really sinking in in how big of a difference it is. I don't imagine you'll regret it.

I would be very interesting to hear your commentary if it is possible to do a drive before install and immediately after, without changing all sorts of other parts. (I replaced mine when I did my timing belt, so even that would've helped smooth out idle in theory, as the belt was real old, and had probably stretched a bit.)

I've spent money in a couple other places that it may not have been *entirely* necessary, but don't regret that either. I wanted to do a header as part of my turbo/exhaust upgrade and decided to spend the extra money on the Holy Header. Needed? Nah, not really, but I did want an EL header, and it seemed to be regarded as the best available. When I got to hold it in my hands, and I saw the absolute work of art the casting and welding was (not to mention the sweet sound of non-rumbly efficiency...) I would tell anyone with money burning a hole in their pocket to get one. Fitment was perfect, install took minutes.

My car needs paint, will always be on stock rims, and doesn't have silicon rad hoses, or any engine dress up (as examples). But it does have a lot of money put into reliability enhancement and "safe" power. You get to spend your money where you like!

Edited August 25, 2022 by KZJonny

[DumpsterSoap]

That is good to hear.  I'll try and remember to write up some comparisons when i get one on the wagon, sounds like a very worthwhile modification.  It's always nice spending money on quality parts that make a difference and are healthy for the vehicle.  I am in the same boat is you where I enjoy spending money there than on flashy engine bay parts, but sometimes those are fun to buy too.