WAWalker

Well, if you read the thread.....................I anwsered his question as best as I could, without doing an engine tear down to determine a cause of failure, 50k after the repair. They should last longer than 50k. But I don't believe that "for the life of the vehicle" is a realistic expectation. Without documentation that shows a number of head gasket replacments lasting significantly longer than another 100k, "the life of the vehicle" is just a wild rump roast geuss, when the history of this problem is taken into consideration. I would still like to know how you can be so positive of the reair lasting the "the liftime of the vehicle". This is a burning question in my mind. Sorry, I missed your other post up there. Subaru made an updated head gasket, then STOPPED production of the engine after 3 years. Testing to make sure the new gasket took care of the problem, in order to provide customer saticfaction? They just quite makeing that problem and moved on to another. IMO. I'm not knocking these cars. I drive them, love them, and fixing them pays the bills. I order for ME to provide customer saticfaction, I need have the best understanding possible of the problems that these cars have and the best way to approch repairs and maintanence. I don't get there by compairing them to every other car on the road, or taking what is in some book as gossple.

This may be the problem. Who made the call on not milling the heads? Why were they not milled? These engines, and repairs to, should not be approched with an "all engines are the same" attitude. Chances are the heads were not warped. They are a relatively compact, stout peice of material, and warped heads are not as common on these engines as a longer inline or V8 cylinder head. So warpage is not the only thing to consider when decideing to mill or not to mill. I see the cylinder vibaration/movement causing a slight groove to be worn in the cylinder heads, this should be milled out. I have seen heads with errosion do to improper cooling system maintanence, this should be milled out, and if it can't be the heads are junk unless you can affored to have them repaid cheaper than buying a good core. In rare occasions the cylinder walls will crack. I have seen this on a 2.2L, not personaly on a 2.5L. But have been told that it does happen. Obviously if this is the case the head gasket job will not fix the problem. The cylinders should be closely inspected when head gaskets are replaced. Something is not right somewere to cause another failure at 50K.

And you know this to be a fact, and have documented head gasket replacements on both engines lasting how long, that would back this statement up. [qutoe=Ranger83] My sister in law's failed at 245K after being replaced at 145K.[/qutoe] Post #17 Is one documented case of a head gasket replacement lasting 100k. Not the first that I have heard of. If you could provide a little insite on the cause of the failure and what the updated gasket and proper installation is doing to change the original problem, I would love to here it. Other wise I'm not buying the "It should last forever" line. I see the problem differently in the real world. With proper maintanence, oil changes, air and fuel filter, valve adjustments, and cooling system maintanence, I see no reason why these engines couldn't last 300k. Other than a head gasket failure or two along the way. And judding from the history or these engines, if the head gasket is left alone untill failure, chances are that the overheating is going to shorten the life of the engine, so you will never know if it would have lasted another 100k had the gasket been replaced as a maintaence item. For someone who really wanted to try and make their 2.5L DOHC run for 300k, why would you want to insist on the head gasket never needing to be replaced more than once and run the risk of another failure that may kill the engine. You must explain yourself because I just can't understand. Again I say, it doesn't matter what any Subaru manual, or Chevy, Ford, Volvo.................manual says. You can't learn everything from a book. Experiance is the best teacher. There is no replacement interval for thermosates, water pumps, cam seals, crank seals, rear main seals, oil seperator plates, timing belt tensioner and idler pullies........................Should a person just wait for a failure before replacing these items? Other than the fact that it is a well documented/proven problem with Subaru engines.

Regardless of what any book says............Head gaskets failures on Subarus are a well documented problem. And if you work on enough of them and pay attention to the problem and the avarage milage at which the problem occurs, you can make some every informed decisions as to how to approach repairs and maintanence on a car that someone wants to drive for 200k+. I have sold at least 2 head gasket jobs on DOHC engines that had never overheated as preventative maintanence. The cars were reaching the failure window, and the customer wanted to be sure they didn't have to worry about it, so I am not a bit ashamed of doing it. I can't, at this point, make that kind of call with a SOHC engine because although it is a head gasket failure it is different in many ways. And the milage at which they start leaking does not seem to be as consistent.

If you are looking for info on an '01 2.5L, that is a SOHC engine. Different animal than the '97-'99 DOHC engine that this post was started for. Very important that these two engines and problems aren't confused. Two different problems, and possibly two different causes. I don't know that SOA has done anything other that the stop leak "cooling system conditioner" to rectifiy this problem. The head gasket itself may be the problem in these engines. These gaskets are a joke. The OE replacments are no different than the factory original. And I really don't have a clue what is causeing the leak. I would like to blaim the gasket but the funny thing is the leak is always in the same spot, which makes me thing it could be somthing eles. Anywhoo........Not to be an rump roast, but I think when a thread is started asking about a '98 2.5L the discussion should be limited to the DOHC engine. If there is a question about the SOHC engine a new thread should be started. People get confused. I know some people start thinking that they need the "cooling system conditioner" in their DOHC engine to prevent/fix their head gasket problem. Not going to work.

Yes, I use only OE head gaskets. I personaly don't think the head gasket itself is the real problem in terms of the 2.5L DOHC failures. I believe it is the design of the engine block itself. Yes, there are noticable differences in the upgraded gasket. Will it or does it help? I lean toward a no on that. If the failure is due to what I think it is due to, I think that the graphite impregnated fiber gasket (used on the '96MY 2.5L DOHC) would be a better choice. I can't test that theory on a customers car, and can't afford to do it myself so................... Also I see very few '96 2.5L DOHC head gasket failures. Although there are not as many on the road, only the auto trans cars got that engine in '96.

I have seen them go as soon as 88k and as long as 189k. Most are very close to the 100k mark. I personaly don't think there is any dodging of this problem, if you plan to keep one of these cars for a long time, I think you should plan on replacing head gaskets.

Why is this not worth debating? It is good tech. These cars are going to be around for awhile, why not figure out what the problem is or if there is a real fix that will make the engines last even longer. Manitanance on these engines is not the awnser. I've seen car with all the schedulaed(sp) maintanence done, and still the head gaskets let loose. What is it that you think causes the head gasket to fail? What makes you think that the updated gasket is the fix?

FWIW, I am fully independent from SOA or any of their dealers, other than buying OEM parts. Thought I should let you know since you did quote my post.

Buy the way, I think this is a very good topic. Not boring at all.

OK The difference in the "Phase-I/DOHC 2.5" engine block w/ 4 holes and center thrust, and the "Phase-II/DOHC 2.5" engine block w/ 8 holes and rear thrust, has no bearing on the head gasket issue. All DOHC engines have the internal leak. Have never seen one leak externally. I my experiance, since I've started tracking useage of parts I've done 30+ head gasket jobs in the last 4 years. Looks like most have been '97's but there has been plenty '98's and 9's in there too. Then you have to consider that due to age there are probably more '97's than '98's hitting the failure window milage wise, more '98's than '99's.................Did a '98 Monday, have a '99 comeing next Monday, so they are catching up. The SOHC engines all have the external leak. The only one I've seen that had an internal leak, someone had already replaced head gaskets on once. Don't know what they did wrong, I did not tear down engine. I was able to help customer get the dealer to fix under warranty. Have not come to a conclusion as to what is causeing the external leak and SOA isn't telling cause they aparently don't know. Their campain letter said the problem was fixed mid 2002, but there are 2003's and 4's with same problem. My best geuss is the head gasket itself, they are a joke. So No it dosen't matter what engine block you run, when you look at the cylinders of one with the heads off they are all the same. The ones with problems that is. If they don't have a problem there is no reason to pull the heads and look, is there?

When I do head gaskets on a 2.5L DOHC engine I tell the owners that they can expect another 100k. I don't believe that the new gaskets can fix the open deck large bore of the 2.5L, so I won't stick my neck out to far in estimating the life of new gaskets. That being said..................I will say they shoulda lasted longer than 50k. The lowest miles I've seen the origanals go is right around 90K.

Maybe I not sure exactly what it you are trying to find out. And I'm not sure what you mean by "mixed heritage" engines.

IMO I wouldn't say that '97-'99 was really transition years. More like a good idea gone bad. '96 was a transition year from the 2.2 to a larger more powerful engine, the 2.5. More dispaclement and DOHC's in a search for more power. Immediatly changes were made for the 97MY. Shorter pinstion skirts and solid lifters, again in the hunt for more power. The shortened pistion skirts resulted in pistion slap that cost SOA a lot of money. The head gasket design was also different between '96 and '97. This is conjunction with the larger bore resulted in head gasket failures, that also cost SOA money. I think these issue were probalbly a huge part of reason for another engine design. Historicaly, when Subaru has built a good reliable engine, they have used it for many years. JMO I think everyone is overthinking the "Hybrid" thing. The Hybrid engines that subaru dealers sell are Short Blocks, rebuilt by Cummins for SOA. They were production blocks for the '97-'99 DOHC. They are not nessasarly a mix of the best of two worlds. They are rebuilt lower ends period. You buy one and either use your old cylinder heads as is, have them rebuilt, or buy new, and install them on the rebuilt block. The result being a rebuilt engine that either has the 4 or 8 bolt bell houseing depending on what year of car your putting it in. As I said I don't have all the specifics on the blocks used for the SOHC engines. I don't know that they are the same as the '98-'99 8 hole rear thrust block, or if there were maybe some other changes. I do know that the dealer here needed a SOHC core to send back to SOA at one point in time and had to have a '00 or newer, a '98-'99 8 hole block wouldn't do. I don't know why, and didn't ask, just sold them a block. As far as the head gaskets.........................This has been pretty well documented. The DOHC engines had a internal combustion leak into the cooling system. The SOHC engines have an external head gasket leak, primaraly drivers side bottom rear of cylinder head.

Oh, and as you can see from the first chart, the 8 bolt bell housings started in '98. The bolt patterns are all the same but there are differences between the MT and AT I believe due to different starters. On a MT two of the bell houseing bolts/studs hold the starter on. Were as on a AT one bell houseing bolt/stud and one stud installed in the transmission houseing holds the starter.

This is straight from SOA TSB. This is probably wear the idea of a "Hybrid" 2.5L came from. Unlike the new bare boneshort blocks that could be purcased through the dealers, these rebuilt short blocks come with oil pan, water pump, thermostate and houseing, and oil pump, thus making them "Hybrids".? Anywhoo..................There is the application chart for your '97-'99 DOHC 2.5L engines. Then in '99 production of the SOHC engines started. I still don't have all the specifics on what got the 2.2L SOHC and what got the 2.5L SOHC.

There were 5 different part #'s for the DOHC 2.5L engines from '97-'99. Now Subaru is selling two different short blocks as replacements. Basicly there are two (2) EJ25 DOHC blocks: Four bolt, center thrust carnk. Eight bolt, rear thrust carnk. Will post more info shortly.

If you have ever pulled one of these apart and looked at the way this system works you would see that fluid leaking past these seals would cause a loss of pressure to the transfer clutch pack. A loss of pressure to the clutch pack isn't going to cause torque bind. Torque bind, when not caused by tire size, is caused buy either too much fluid pressure to the transer clutch at the wrong time, or wear in the transfer clutch discs and drive hub that cause the discs to bind and not release. A failed duty solenoid C, or in rare cases a bad TCM will cause full pressure to be applied to the clutch pack. The wear to the drive hub and clutch discs is just that, and the clutch pack and hub need to be replaced to fix.

If that pic that was posted is the '97, it is not just a matter of swapping body parts from your '95 to fix it. None of the body in the back are bolt on parts.

Just inboard of the jack point on the pinch rail, in front of rear tires, is the mounting point of the crossmeber that supports the front of the rear differential. If the lower part of the body mounting plate is bent up and touching the crossmember, you will get a considerable noise on decel. If this is as clear as mud, let me know, I could get some pics and post them up. I'm thinking you may have bent this jacking the car up. If you have a floor jack, jack under the center of the rear diff. This way you lift both tires at the same time and don't have to worry about damaging anything.

I believe that the body's are the same. I know they made so changes in '98. Go to 1stsubaruparts.com, look up body panels and see what year range they fit.

Were did you place the jack when jacking the car up?

Beware of ebay cars. Is you 95 a wagon or sedan? Is the 97 a wagon or sedan? Is it w/ or w/o Outback?

Yes, fully collapsed(sp?) lifters in an EA82 can very much sound like bottom end noise. Collapsed(sp?) lifers in a EJ22 sound a lot different. I dissmissed hydrolic lifter noise due to the fact that a '98 EJ22 doesn't have hydrolic lifters. True, internet and phone diagnoises can never be guaranteed. But in the last 10+ years of wrenching, the last 5 sepcalizing in Subaru repair, I'll take another stab at it. Listen at vavle covers with a stethascope, then listen at top of block above all 4 cylinders. If it is piston slap I'll bet #4 is the loudest. If it is valve train noise someone has been in there doing somthing to change the valve adjustment and didn't get it right.

Piston slap in post '96 EJ22 is not as common as the EJ25 piston slap, but not unheard of. In '97 they shortened the piston skirts, this is the cause of the pistion slap in the 22's and 25's. Also in '97 they went to solid lifters so the noise is not HVLA noise. If the valve are way out of adjustment they would make noise but more likely than not it is piston slap. I have worked on a couple EJ22's with piston slap worse than any EJ25 I've ever heard, and no it doesn't always go away.