From the reading and listening I’ve been doing since this bs started with my Subi, and as a guy that R&R’d rod bearings on a 70 GTO 400ci Hurst 4-on-the-floor in my youth - more than once - I was a wildman on the street - they say God watches out for young children and idiots…
Anyway, I would agree the most likely failure is the gasket itself. It’s the most sensible. Even if it was a design mismatch between the gasket and the mating surfaces or bolt strength whatever, the failure still lies with the gasket.
But I’m not lettin’ Subaru off the hook! They captained this ship, and now it’s a wreck in my backyard!
Exactly, @millhunk - Subaru’s been dealing with this problem for 10+ years, they set the gasket specs. And if it was just a gasket problem, why does the new design eliminate coolant passages through the head gasket?
Head gasket issues have been around for a lot longer than 10 years; more like 30 and counting.
I don’t know how they would get away with no coolant passages without frying the heads. The gaskets certainly appear to have coolant passages and so do the cylinder heads.
The coolant’s carried in outside-the-head pipes, oil passages through the head, I read…
Here’s more discussion of the changes:
It will be interesting to see the details on that. Separate block and head cooling circuitry doesn’t tell me much.
A long time ago Subaru ran an external coolant pipe to the cylinder heads but it was a feed only as I vaguely remember.
I’m thinking the bigger change on the new engine block is from an ‘open deck’ to a ‘closed deck’ design, like Subaru uses in its turbo engines, which haven’t had near the amount of head gasket problems, as far as I know.
If you ask Subaru…The will refer you to the “NEW AND IMPROVED HEAD GASKET SET” Ive bought more than a few of these and none have come back yet…the last one was about 3 yrs ago…and the others are all out there a good bit longer than that. Haven’t been blamed for any new failures YET…so…I dunno.
Blackbird
For what it’s worth, this entire head bolts don’t need retightened thing started back in the middish 80s and Subaru is not the only one where problems surfaced.
Fiat and Nissan did the same thing and Nissan especially suffered. After the head bolt retorque was eliminated the head gaskets started puking oil from the pressure port that fed the overhead camshaft. A retorque may have stopped the leak but policy was to replace the gasket; some under warranty and some not. I did 2 or 3 of these per week.
Another factor could be this. A lot of guys I’ve worked with (including some Subaru Master Techs) never checked the cylinder heads for flatness. My unscientific guess on the number of Subaru warped heads I’ve seen is probably in the 50% range. A max of .002 is allowed and I’ve seen some at .005-.007 even on engines that were not overheated.
Logic would dictate that a short cylinder head such as a Subaru should be near impossible to warp but that’s not the case. My opinion is that it’s caused by heating/cooling cycles, compression pressures, and the previously mentioned lack of head bolt retorque, gasket crush an relaxation, etc.
So if a head gasket job on Subaru goes south later on one has to wonder if a warped head that was not checked is the cause.
Yes I would agree with you OK44…that Subi head is a small head and you wouldnt think it would or could warp very easily. Since I was trained or learned from OLD OLD SCHOOL Guys like my Father and Grandfather… I’ve NEVER installed ANY cylinder head without my Machinist Ruler taking a looksie FIRST. I mean there is NO POINT in going any further if we have out of spec PARTS now is there? I ALWAYS CHECK the HEADS…AND THE BLOCK prior to re-assembly. Its just the correct way to do things. So far NONE OF MY SUBI jobs have come back to haunt me. KNOCK ON WOOD.
Its funny…this business in kind of THANKLESS… You do a great job and repair the issue and YOU ALMOST NEVER HEAR ANYTHING …NO NEWS…NO HAPPY CUSTOMER SINGING YOUR PRAISES…
Its only when $%^& is hitting some sort of Fan somewhere that you hear back on how you did or how the job went. Thats why I ALWAYS call my customers or friends or whomever I have helped AND I ASK…HOW IS EVERYTHING? NO leaks? No coolant issues? No Problems? It is only then when I hear any kind of Positivity.
So for the record…using the “New and Improved Subaru Head Gaskets” Level checking the Heads as well as the block…and simply being meticulous in all endeavors of said job…None of my Subi’s have returned. Is this the solution?
To this day I am still haunted by the guy who said there is a block defect in these particular vintage Subarus… THATS A HORRIFYING STATEMENT for someone like me… ME NO LIKEY…so I hope that guy was incorrect because the implications are far reaching if there is a defect and I “Conned these nice people into not giving up on their Subarus”
Blacbird
Here’s what the Subaru block’s ‘open deck’ looks like. See how little metal there is around the cylinders for the gasket to seal against?
I understand the open block concept and theory about head gasket failures attributed to it.
Point being that the block is not an issue if a proper job is done when replacing the head gaskets so that tells me the block wasn’t the problem to begin with.
If the block was the problem then the new head gaskets would surrender and no sane mechanic would replace gaskets in an engine like this.
The same thing happened with Nissan and there was no open block design. No problem as long as the head bolts were retightened. Once the no need to policy became effective they leaked in droves.
You know, my sister had a 2000 Nissan Sentra that blew a headgasket at around 60k miles. But, my sister and cars…I remember trying to check the oil in that car once - it took about 30 minutes and a pair of vice grips to do it - then I had to go buy a new dip stick from the Autozone.
Yes the cylinders are “Siamesed” and while that does limit sealing surface this is no way uncommon in the “engine world”. This is an area that’s harder to seal but if its flat and the head is equally so…then they seal. None of this is uncommon…lots of engines are of similar design. In fact the area between the cylinders is actually larger than the perimeter sealing surface is by almost a factor of 2… I see no reason why any of this should leak when the head is square, the block is square and you have a gasket of appropriate design and material. There’s nothing really strange or wrong here.
Blackbird
So that picture that texases posted of the block - am I right in assuming that those void spaces around the cylinders are kind of problematic? I mean, Subaru trying to eliminate weight? Really? How much weight vs how much freakin bs is caused by thermal expansion of that thin freakin metal!!??
Okay, I’m gonna rant…What’s the 3 most likely things to put you on the side of the road? Here they are in order: Battery, tires, and cooling. The fact that Subaru would make a decision to save a little weight by creating an even BIGGER risk of any one of those three, makes me want to choke an engineer!
Okay, I’m done. I think the think that bugs me most is that the car is a really good car otherwise. I really like my Subi, and that’s why it’s worthy of a headgasket change.
Open deck designs are pretty common but Subaru has had more problems than others it seems
Its not about weight per say Millhunk. Its about packaging and also trying to enlarge a design that started out at 1.8 litres I believe. Somebody correct me if I’m wrong here. Usually we see this happen when an engines capacity grows but its dimensions stay the same. I can assure you it is Not Cheap to redesign a block and have the tooling made to make the castings…so they don’t try to do that very often… then when the capacity is increased over time…we get cylinders that are too close in bed together. Trust me you would go broke in a hurry if you made a new engine every year from the ground up.
Blackbird
Does anyone know of this issur in the2011 tribecs 6 cyl.
I just had it happen to me with 65,000 miles.
I hope the new system automatically closes inactive threads after 90 days. In the meantime OILWELL start your own thread.
@“VOLVO V70”
there’s another thread which should probably die on its own
But the guy keeps posting, with no new results or progress :trollface:
I think we all know who I’m referring to 