Worth replacing head gaskets during ARP install ?

Gypsy62 · **Posted:** Sun Feb 21, 2016 4:06 pm

As a former Subaru mechanic, as I prep to upgrade my 145k '05 CRD into the "diesel-lifespan" zone ala this site's outstanding advice, I'm very tempted to swap in a fresh HG while the bolts are being tossed for studs.

Pros?
Cons?

Drawing from >60 '96-'04 2.5liter Soob HG R&Rs, it's hard to resist installing a fresh HG while the topside is cleared: no structural head issues to sweat, no decking, etc. Just the onward confidence of a spankin' new HG.
One less-touted 'pro' is the opportunity to inspect/decarbon the piston chamber surfaces (less sleeves). Minor (nay, irrelevant if etecnos already in -hand), but in the CRD I suppose it would also permit you to ID if yours still has ceramic glo's by observing tips. Head-off (versus head-on) would also eliminate the anxiety of old ceramic glos breaking into the piston chamber during etecno swap.
It appears that ARPing the studs/rockers while leaving the head in-place avoids messing with the timing alignment/components. LJ posts suggest that the tbelt R&R learning curve (& special tool required) may make the strongest argument against preventative replacement of the HGs.
Particularly when nailing tbelt R&Rs, the stakes are high and familiarity is huge. Re Soobs, my first tbelt required >7hours, subsequent <2hrs. I'm guessing similar #'s echoed by CRD vets.
Maybe the crucial criteria would be knowledge of tbelt/pulleys history and condition: if there's any doubt whatsoever about the tbelt/pulleys when tackling the ARPs, setting aside the 'relatively' nominal additional parts cost, does(n't) it make sense to combine all of the following improvements simultaneously:
ARPS/Tbelt, pulleys/Weeks I, II/Etecnos/ (Head Gasket) ?

Thoughts?

olypopper · **Posted:** Sun Feb 21, 2016 4:32 pm

Do the head gasket. If you are down as far as being ready to install ARP's the you are really close to pulling the head and knocking it out......at least the CRD head gaskets are better than Subaru head gaskets or you'd have done one years and many miles ago!

And the weeks kits are great and eliminate yet another place for problems down the road.

dhenderz · **Joined:** Fri Dec 11, 2015 9:26 am **Posts:** 164

Gypsy62 wrote:

It appears that ARPing the studs/rockers while leaving the head in-place avoids messing with the timing alignment/components. LJ posts suggest that the tbelt R&R learning curve (& special tool required) may make the strongest argument against preventative replacement of the HGs.

Not true. You have to pull the cam carrier/intake to gain access to the head bolts (studs). Therefore you will be required to pull the cam pulleys and timing belt.

papaindigo · **Posted:** Sun Feb 21, 2016 5:22 pm

My personal opinion is ARP studs are a bit over the top as a preventative maintenance item as you do have to go in further than just a TB job to remove the valve cover/cam holder to get to the head bolts. That said there are several reasons that might get you in that far (rocker issues from wear or jumped time or a head related coolant leak) and if you are already in that far for whatever reason then I'd say do the ARP studs which is what we did on stoutdog's 06 due to a glow plug tip issue.

flman · **Posted:** Sun Feb 21, 2016 7:08 pm

With a MLS I would just put in the studs, but then again 145K on these questionable engines, maybe a HG is not a bad idea? I just did studs on my Libby with about 60K on the OD, but the other with 100K need gasket and head any ways.

geordi · **Posted:** Sun Feb 21, 2016 7:28 pm

Quote:

Maybe the crucial criteria would be knowledge of tbelt/pulleys history and condition: if there's any doubt whatsoever about the tbelt/pulleys when tackling the ARPs, setting aside the 'relatively' nominal additional parts cost, does(n't) it make sense to combine all of the following improvements simultaneously:
ARPS/Tbelt, pulleys/Weeks I, II/Etecnos/ (Head Gasket) ?

This is exactly the list you should be doing, because to dig down to the head bolts, you *will* need to remove the complete timing system and all the labor fully overlaps.

This is rapidly becoming the more popular service that people hire me to do on their CRDs, I've done probably about 20-25 ARP stud sets by now if not more. You sound like you have the skills though, but be sure you are familiar with the procedure before you start to minimize your downtime. The book value for this job is about 18 hours, I can do it in about 10.

If you are not currently losing coolant and getting low coolant alarms, then your head gasket is just fine. This is a multi-layered-steel gasket, and it does not fail on its own. What fails is the clamping force of the crap factory bolts, and then the 2500+ psi combustion pressure starts forcing its way into the leaves and finds the water jacket. If you aren't losing coolant, then you should be just fine with swapping one-by-one to the studs and driving on. That is what the vast majority of stud kits I have installed have gotten, and they are all doing just fine. Even minor leaks can be cured just with fresh clamping, but it is better to not have a leak at all.

Gypsy62 · **Posted:** Sun Feb 21, 2016 7:32 pm

Unrelated, but I'm attemting to post instructional pics to my other thread re "Toad-wiring a CRD".
Pics prohibited? If allowed, then how and where can they be attached?
Thanks!

geordi · **Posted:** Sun Feb 21, 2016 7:39 pm

Gypsy62 wrote:

Unrelated, but I'm attemting to post instructional pics to my other thread re "Toad-wiring a CRD".
Pics prohibited? If allowed, then how and where can they be attached?
Thanks!

You have to have them hosted somewhere else and then use the img tag to link the image to your posts.

I personally use the Dropbox service (it's free) and use the "public" folder to put any images in.

If you haven't signed up with Dropbox, use this link and we both get extra free space: https://db.tt/EAx8lor

flash7210 · **Posted:** Sun Feb 21, 2016 7:40 pm

You have to upload your pictures to a image hosting site such as photobucket.
Then you put the [img] link in your post.

And why do your toads needs wiring?

Mountainman · **Posted:** Sun Feb 21, 2016 10:24 pm

Pulling the head is about twice the work of just leaving the old HG in there, and then I insist on resurfacing the head, checking for cracks, and getting a valve job if they need it. I would pass on the HG, mainly because there's a lot of work and expense beyond the one for one ARP job. Oh, I've also noticed that every exhaust manifold I pull is warped, and that's another $50-$100 to get it milled flat. I got 3 done at one time for $100, but the machinist said that the setup is a pain because there isn't a flat surface to push against or grip, so just one would have cost me $50+.
The only thing I like about pulling the head is that it gives you a chance to get the EGR port on the exhaust manifold completely sealed off, but then again, that's even a little more $$$

Gypsy62 · **Posted:** Sun Feb 21, 2016 10:52 pm

Geordi; dropbox working. Thanks!

Re HG: if doing tbelt, etc., what about replacing the water pump along with the front main/cam seals? Any other cogent seals?
How pricey and dicey are these water pumps?
Add replacing the thermostat (?). As awesome as the member-made unit is, for me it's currently a stretch to fork the franklins for that sexy bit of hot metal. Maybe next lottery.
I always add all the above parts when doing Soob HG jobs.
Re KJ, Mileage-driven decision?

geordi · **Posted:** Mon Feb 22, 2016 2:04 am

Replacing the front half of the water pump is all that is required, unless you like suffering and pain. One o-ring. Buy the Graf water pump from IDparts (comes in the full timing kit) and that will be all you require for the timing components.

As far as the rest, IDparts carries everything you will need.

Did you use my link to set up Dropbox, or did you already have it? I'm curious b/c I don't see any update of space, and I'm not sure the link actually works.

Worth replacing head gaskets during ARP install ?

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