H6 HG replacement possible without pulling engine?

[jonathan909]

I have some minor crap to take care of first, but the next big job is going to be head gaskets in the '01 H6 OBW we picked up cheap last winter because the PO had started pulling it apart and quickly found himself out of his depth.

I've been assuming that I'll be pulling the engine because everything looks just that much tighter in there (than the EJ25 OBWs and Foresters which I've done in situ) .  But I'm just browsing the TSM now and it says the heads can be done without pulling the motor.

Can anyone confirm/deny this and relate helpful experience?

Edited April 10, 2021 by jonathan909

[idosubaru]

I’ve done Subarus insitu, including H6s, but not an EZ30.  I don’t mind doing them that way sometimes but the EZ would be a time sucking basket case. Have multiple jacks so you can tilt the engine to a favorable angle side to side. Lift drivers side while working on drivers side for example. Almost roll the engine over.

What is a TSM and where does it say it can be done in the engine?

[jonathan909]

Technical Service Manual aka FSM - I use the terms interchangeably (sorry - I'm always jumping between mfgrs).

On page ME(H6)-22 it says:

E: PROCEDURE S143001E45
It is possible to conduct the following service procedures
with engine on the vehicle, however, the
procedures described in this section are based on
the condition that the engine is removed from the
vehicle.
Camshaft
Cylinder Head

I mean, if it's sorta reasonably possible I can dig in, and if it gets too miserable (e.g. tilting the motor as you describe) I can always say "screw it" and yank it.

[CNY_Dave]

I favor the JDM engine route.

[jonathan909]

What, you mean just replacing it?  Sorry, man, I don't spend that kind of money on cars - I need it for boats.

I'm sure I mentioned this here a while ago, but if not...

Back around the beginning of last year I drove by one of those portable moveable-fluorescent-letters roadside signs, set up to promote a used-car dealer. 

Sign said "30 CARS UNDER $15,000".  Doing the mental math, I drove on thinking, "yeah, that's about right".

Edited April 11, 2021 by jonathan909

[GeneralDisorder]

My shop, as is the case with most dealerships, will not perform HG's on any H6's. 

Replacement JDM engines are CHEAP. Much cheaper than we would charge for a HG job. 

In our opinion, the EZ30's are good for about 175k to 225k and then they get replaced. 

GD

[jonathan909]

What's the problem?  Just too much time+effort to do the job, or is there a problem with the results?

[GeneralDisorder]

It's more labor than a 4 cylinder - which currently goes for $2500. The H6 would be more in the realm of $3500 - $4000 when you consider cylinder head machine work, labor, etc. 

You can frequently get the H6 JDM engines for half what a typicaly H4 goes for. Usually about $1200. They are cheap and low mileage. Due to lots of supply and relatively low demand. 

The math is easy from there. 

GD

[jonathan909]

Sure, I get it.   This is a pure cost-effectiveness argument rather than there being something reliably unrepairable about the EZ30.

[idosubaru]

The timing chain covers in H6 vehicles that have been in rust prone areas would be a point to note. Those 60 bolts can be bad enough they won’t come out with the intended bits to remove them.  Be ready to address those if they appear rusty. With almost 60 of them you don’t want each one taking 3 minutes to access or drill out - that would be 3 hours just to remove the outer cover. 

you could also try to determine which side is failed and only replace the one bad side. Although I’m not sure how - pull plugs?

the ones I’ve done have worse high and low spots than 4 cylinder Subaru engines. I don’t know if that’s just coincidence or H6s are more prone to that, but I resurface them all anyway. 
 

There is one nod to reliability driven decision for JDM. H6s are like DOHC head gaskets and prone to random overheating in the initial stages. I’ve seen overheating events spaced out by months.  This also means they’re far more likely to be limped along, improperly diagnosed and repaired and overheated again over long periods of time.  These repeated overheating attempts are bad for the lower end bearings and a valid reason for JDM. The ones I repair I know the vehicle and owner well and have an idea how bad it was overheated.  The ones I replaced have signs of significant or repeat overheating events or unknown/unsure.

[jonathan909]

When PO started in on it, he'd only bought one gasket, so it's certain he only planned to do the bad side, which is obvious - it's a serious coolant leak to the great outdoors.

I'd figured on doing both Just Because, but given what you gents are saying I may just do the one.

On the other hand, the effort overhead, particularly in the timing cover alone, is significant.  I'll have to think about it and see how it goes.

[1 Lucky Texan]

I've only read about taken the motormounts loose and using ratchet straps to pull the engine away from the working side.

[jonathan909]

Understood.

I still plan to go ahead with this, but want to stress that I absolutely respect the rationales offered above.  But where they are driven by necessary commercial/time considerations, I'm not so constrained; if I have the time available to invest so I can put my limited cash elsewhere (my eye's on a Supercat 20 in Texas at the moment), that's what I'm going to do.  But the time/money equation isn't the only thing driving me, either.  As the old Stiff Records slogan goes, "Try everything once, except incest and folk dancing".  I haven't yet pulled apart an EZ30, I know that I'm going to learn some new stuff, and if that includes, "They were right, this is stupid, I wish I hadn't done it, and it's time to buy a JDM", I can accept that outcome too.

[idosubaru]

1 hour ago, jonathan909 said:

Understood.

I still plan to go ahead with this, but want to stress that I absolutely respect the rationales offered above.  But where they are driven by necessary commercial/time considerations, I'm not so constrained; if I have the time available to invest so I can put my limited cash elsewhere (my eye's on a Supercat 20 in Texas at the moment), that's what I'm going to do.  But the time/money equation isn't the only thing driving me, either.  As the old Stiff Records slogan goes, "Try everything once, except incest and folk dancing".  I haven't yet pulled apart an EZ30, I know that I'm going to learn some new stuff, and if that includes, "They were right, this is stupid, I wish I hadn't done it, and it's time to buy a JDM", I can accept that outcome too.

The good thing is that you’ve essentially already done this.  Someone else posting the same question might be ill equipped and way over their head.  It’s laid out like any other Subaru engine in terms of form factor. the ez engine bolts up to the transmission and engine crossmember of the 4 cylinder Subarus you’ve done.  The timing chain is the same location and “line up the marks” ideology as Subaru belts, with one simple measurement suggested in the FSM.... Just with 100 asinine allen head cover bolts.

If they’re rusted I’ve ordered a complete set of hex head bolts to replace them with instead. I posted a thread how to remove rusty ones with a chisel in a few seconds rather than drilling/torching.

If it’s leaking coolant externally you might be able to avoid the headgasket replacement altogether. 

*Initial* *external* leaks of *factory* installed stock gaskets respond with basically a 100% success rate to Subaru $2.50 coolant conditioner. Each of those starred words is chosen carefully.

If it’s the original gasket, which is likely, and it wasn’t left go to long, it would work here as well.

But then you’re already sitting on a partially disassembled engine so working backwards might not be a good fit.

Edited April 11, 2021 by idosubaru

[jonathan909]

Well, I was - but it's pretty much back together now.  This was a matter of necessity, because around here it's a real problem if a car won't move under its own steam.  PO had really just started the job - rad, AC condenser, intake manifold, crank pulley out - before realizing what he was getting into.  My guess is that he took one look at the timing cover and threw in the towel.  I mean, he was trying to do this on his back lawn, not even on a concrete pad.  So after I got it home I decided that until it made its way up the queue it should be able to start and run - which would also help me assess the leak, which is pretty bad.

I've had a couple of good experiences with the coolant conditioner, but I think this is rather too severe for that, and the car and motor (not its first, as I recall) came with a really long story too complicated to commit to memory.  So I'm making no (optimistic) assumptions about my initial state beyond "looks bad".

Oh - and as for the timing cover bolts, between here and Texas (where this car apparently also spent time) it's pretty dry, so I don't expect rust to be a big problem.

Edited April 11, 2021 by jonathan909

[1 Lucky Texan]

Ido has a technique that seems to work. The other way I read of was an impact screwdriver, the kind you whack with a hammer. I expect it is the 'percussive shock' in common that helps them work.

 

cue;

 

 

Edited April 11, 2021 by 1 Lucky Texan

[idosubaru]

4 minutes ago, 1 Lucky Texan said:

Ido has a technique that seems to work. The other way I read of was an impact screwdriver, the kind you whack with a hammer. I expect it is the 'percussive shock' in common that helps them work

Definitely use that first. Maybe even torch it first.  I’ve got a good one, it wouldn’t work on any of the 50+.  there were only 4 that came off with the impact. The rust flaked off the Allen head corners leaving nothing to grip too. 

[jonathan909]

Feynman's actual van!  Not a realistic depiction of working with thermite, though.  You don't light that stuff with a match...

Edited April 11, 2021 by jonathan909

[1 Lucky Texan]

worked with a guy with railroad experience,  used thermite packs for welding rails. 

 

 

[1 Lucky Texan]

sorry your thread turned into such a 'train wreck'.

 

[CNY_Dave]

I had a coolant weep from a head gasket for almost 200,000 miles, the subaru / holts rad weld conditioner kept it under control up to and beyond the combustion leak into the coolant.

 

If something was beyond a weep or maybe a small trickle yeah it probably wouldn't work.

[Numbchux]

It may be possible to do in the car, but it's going to be a nightmare. Like the DOHC 4-cylinders, the cams have to be removed to access the head bolts. When you take the exhaust cams out, the exhaust buckets will fall out unless you can roll the engine on it's side.

If you insist on doing the repair, do yourself the favor, and pull the engine.

 

 

@GeneralDisorder, do you have a preferred JDM importer?

Edited April 12, 2021 by Numbchux

[GeneralDisorder]

We have used Foreign Engines Inc. in Lynwood, WA on many occasions. 

GD