Stripped head bolt. Helicoil? New block?

[paraparker]

Hi. Long time Subaru owner. New here. Searching around and seeing a lot of helicoil stuff for plugs, but I'm wondering how wise a helicoil would be for a stripped head bolt?

Quick(ish) backstory. Searched high and low for a nice first gen Legacy (hard to find where I live in Montana these days) and finally picked up a '94 Alpine Sport in Denver in really, really good condition. It has a fraken2.5 in it though that was getting head gaskets replaced as I waited to drive it home to Montana. Drove the 1,100mi great! Nice torque on the 2.5. A week after getting home coolant starts blowing everywhere, I have no heat and the overflow tank is bubbling like an aquarium... gaskets already?! How is this possible?

Local mechanic notes cheap NAPA gaskets and a stripped head bolt that destroyed gasket quick. Glad I made it back to Montana! Local mechanic doesn't want to helicoil, but instead swap in a rebuilt 2.5 SOHC he has for $2k installed with 12mnth/12,000 warranty. 2.2s are rare around here to say the least & don't wanna go JDM route etc, but we're going to try the local junkyard at least to see if we can find something cheaper. Don't want to spend $2k for his 2.5, but thinking a helicoil might be risky in that high pressure spot not to mention labor cost of removing, shipping to machine shop, re-install etc. etc.

What would you do?

"Ruby" thanks you for your kindly input.

[rallyak]

Helicoil should be fine, and make sure they lock-tight in. Also to avoid any other ones possibly striping out, I would suggest head studs. I've never helicoiled a Subaru head bolt hole but have done it on other engines when I worked at a local machine shop. I never had one come back.

[Someperson]

helicoils are quite strong.

[fireman2101]

I used a helicoil in a Cadillac 472 motor for 5 years and never had a problem and I put it through a lot of abuse. If they are done right they are very strong.

[wtdash]

BTW, a SOHC 2.5 longblock (heads and intake manifold) would be the '99+ phase 2 and its wiring harness isn't compatible...and your 2.2 Phase 1 intake wiring harness won't work on it (easily).

You could just use the 2.5 short block w/the existing 2.5 (DOHC ?) or 2.2 SOHC heads and intake.

$2K is a lot for engine swap, IMHO.

You don't state WHERE in MT, but I know a few mechs around Missoula that might have a 2.2 avl.
TD

[paraparker]

BTW, a SOHC 2.5 longblock (heads and intake manifold) would be the '99+ phase 2 and its wiring harness isn't compatible...and your 2.2 Phase 1 intake wiring harness won't work on it (easily).

Yeah, but I think they've already accounted for that with the previous swap as the 2.5 already in it ran great (until the gasket blew/bolt stripped of course). I recall the local mechanic murmuring something about a different harness in there. There is a local junk yard with a 2.2 for $850, but it's buried in snow and would be "weeks" to remove from the donor car. The guy is notoriously lazy. Haha. I'd save about $500, but can't wait that long. Plus I work at a ski resort so like the extra grunt of the 2.5 to be honest.

$2K is a lot for engine swap, IMHO.

I'm up in Whitefish North of Kalispell where everything costs twice as much as anywhere else. I knew/know that $2k is a lot for a swap, but it's totally rebuilt and he'll warranty it for 12 months/12,000 and I'm supporting a local mechanic so... yeah it'll hurt, but I'll hopefully have a sweet, reliable Alpine trim '94 for years to come.

I'm tempted to get the 2.2 junk yard for my '72 VW camper I'm restoring (slowly). Be about the same swapping that in as totally rebuilding my current Type IV 1700. Hmm. First things first.

[mike-tracy]

The problem with the phase II engines are that the cam timing marks are radically different from the phase I's. Any phase I DOHC ej25 can be controlled by a phase I ECU due to compatible cam gear timing marks.

Not saying the problem is insurmountable, but this isn't a 1:1 swap.

[paraparker]

The problem with the phase II engines are that the cam timing marks are radically different from the phase I's. Any phase I DOHC ej25 can be controlled by a phase I ECU due to compatible cam gear timing marks.

Not saying the problem is insurmountable, but this isn't a 1:1 swap.

Mechanic just called and the head bolt "insert" (not helicoil I guess) is installed and working he says. He noticed it's a '98 block with '04 heads, which is why the previous mechanic had problems with piston slap 'cause he used the wrong thickness gasket I guess. A real Franken-bu for sure. Says it's running well though and he put in a new clutch and throwout bearing kit while he was at it. We'll see what happens from here, but I'm just glad to have it back. Hope the insert holds.

[kimokalihi]

Piston slap? That's where the piston slaps the cylinder walls. Sounds like he's talking about piston to valve contact or something. 04 heads won't work unless they are running an OBD2 ECU. I think your mechanic doesn't know subarus.

[paraparker]

Piston slap? That's where the piston slaps the cylinder walls. Sounds like he's talking about piston to valve contact or something. 04 heads won't work unless they are running an OBD2 ECU. I think your mechanic doesn't know subarus.

Probably my poor terminology. When the Denver mechanic did the head gaskets he reassembled and said the piston heads were hitting something. He put in thicker gaskets to correct that. That's when he didn't tighten a head bolt correctly (or whatever caused it to strip) causing his gasket job to fail. My local Montana mechanic (who's been working on Subarus for decades) just did an insert to fix that head bolt instead of me having to buy a "new" motor. That's when he identified the '04 heads on the '98 short block. They must have accounted for the ECU originally in Denver because the car runs fantastic.

[kimokalihi]

Interesting. Could you snap a couple pics of the engine/harness/ecu?

[paraparker]

Interesting. Could you snap a couple pics of the engine/harness/ecu?

Sure. I'll try to get some uploaded tomorrow. Would be curious myself to see what the heck is going on with my Franken2.5.

[paraparker]

Interesting. Could you snap a couple pics of the engine/harness/ecu?

Here's a couple photos. I'm an engine noob so will need to Google where the harness/ecu are. These photos are probably pretty useless really, but might show the macro picture.

Ran great up the mountain this morning to the ski resort I work at. Love the 2.5 torque band compared to the 2.2. Only issue I saw is that when I pull up to a stop sign/light it'll stall out. I've read that could just be the ECU "re-training" itself. Dunno. By the time I got up the mountain it wouldn't stall when I stop, but does still dip almost to 0 before recovering to around 600-800 after bouncing around for a minute. Hmm. There is a bit of a ticking in 3rd around 2,750 RPM, but not in any other gear at that RPM. Hmm.

We'll see how long she lasts I guess. My local mechanic said whom ever worked on it in Colorado were either Russians or Gorillas. Ha!

Basic engine shot:


Intake:


ICV welded to intake?!


'Nother engine shot: