life of replaced head gasket

[idosubaru]

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.

this is true, but the "life of a replaced head gasket", the title of the original post, is applicable to both engines. there is no difference in the life of a DOHC replaced head gasket and a SOHC replaced head gasket, if properly replaced they should both last the life of the vehicle. the real tangent was the "head gasket replacement interval" comment. this likely needs to have a thread of it's own since it is not common practice nor is it mentioned in any FSM, owners manual or considered standard practice on any vehicle, Subaru offers no documentation of this, nor do i recall anyone in the US ever mentioning this. like i already said, the owners manual doesn't mention replacing the headgasket and there's a reason for that.

[Petersubaru]

Thanks for clearing up any possible confusion between the different motors, that may have developed ... I seemed to understand that this thread was a general discussion about headgaskets, even though a late '90s car was mentioned ...anyway, the varous stories that all the members gave was appreciated..

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.

[WAWalker]

this is true, but the "life of a replaced head gasket", the title of the original post, is applicable to both engines. there is no difference in the life of a DOHC replaced head gasket and a SOHC replaced head gasket, if properly replaced they should both last the life of the vehicle. the real tangent was the "head gasket replacement interval" comment. this likely needs to have a thread of it's own since it is not common practice nor is it mentioned in any FSM, owners manual or considered standard practice on any vehicle, Subaru offers no documentation of this, nor do i recall anyone in the US ever mentioning this. like i already said, the owners manual doesn't mention replacing the headgasket and there's a reason for that.

 

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.

[Petersubaru]

Other manufactures like VW have documented headgasket failures and many people who use these vehicles FAR from home include the HG replacement as a maintenance item,(without any arm bending from the mechanic).. even though it is not mentioned in the owners booklet or any technical up-dated reports..in some cases it is prudent to have this job done...

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.

[idosubaru]

this thread was not started to discusss whether or not the EJ25 has headgasket issues and whether they can or should be replaced as PM. his has already been replaced, he's beyond that point. he's asking about the expected life of a replaced head gasket. with the updated headgasket and properly installed it should not need to be done again.

[Petersubaru]

If you "think it could be something else" other then the gasket ...could there be a possibility that the head bolt backs out ever so slightly...I say this because on the older vehicles ('80s) at least from my experience the leak also occurs at the same spot for my cars (passenger side, at the rear) ... the mechanic who previously worked on my car(s) for three HG repairs among other subarus felt that when removing the head bolts, there was one that seemed to be easier to immediately "break lose" (the last head bolt toward the rear)...3yrs ago I had to replace the headgasket on one of my older subi's and tried testing this theory useing my torque wrench(snap-on and tested to be correct)..the rear bolt was not even close to proper specs,... the Other bolts were tight,... maybe ARP's would work better....who knows??..I can only assume that when the HG repair was done that ALL the bolts were tightened to spec.................................

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.

[idosubaru]

by 1980's do you mean the EA82? the EA82 and EA82T headgaskets should be retorqued. install, torque, run engine to operating temperature. shut it down and tear it all back apart again to retorque the head bolts. Fel-Pro makes a permatorque gasket that is not supposed to require a retorque. they seem to hold very well for the many people on here that use them and recommend them over all others. what gaskets were used and were they retorqued? i do not know why you'd find the bolts loosing torque, that would be an interesting topic for another thread, have you ever asked, i'd be curious to see what everyone says about that? i know the turbo's tend to fail at the rear passengers side cylinder due to heat. there may be other similar contributing factors. the leak starting there and localized heat build up may possibly cause the bolt to loosen or just reduce the gasket material between the head and block, thereby making it seem loose eventhough it hasn't actually "backed out". 'ive seen a number of headgaskets that i've pulled where the headgasket was severly damaged, with much of the material missing, the missing material may put less pressure on the bolt head. it's hard to say which came first.

 

another very important issue which is more evident on the older subaru's you speak of, is the threads. the older subaru's tend to have very corroded and dirty threads when you pull them apart. even engines in good running condition that i've disassembled with no head gasket issues will have corroded bolts. these bolts and the bolt holes need to be meticuloulsly cleaned to make sure they are actually torquing properly. the proper torque, sequence, and retorque means nothing if the bolts holes or bolt threads are not in excellent condition. i clean them and run a tap and die over each bolt and bolt hole when i do my headgasket jobs. for the sake of time, i'd suspect most mechanics do not do that. that being said, EJ engines are typically much newer and fewer miles and do not seem to have the amount of corrosion and dirty threads that i see on the older 80's EA stuff.

 

headgaskets have to be done right to hold. the way they are done makes the difference between them lasting and not.

 

as a side note, with cooling systems in excellent condition, the EA82 will keep it's headgaskets for the life of the vehicle. problem is, after 20 years or a quarter of a century, it's hard to keep a cooling system in excellent condition. with all those years, miles and multiple owners there's just no way to gaurantee the vehicle hasn't been run hot. heat kills gaskets and seals and headgaskets see it up close and personal when it happens.

 

things often fail at the same point. the internal HG, the external HG, the dodge neon HG fiasco, they all fail in similar modes. they will fail at the weakest point of the system, so it makes sense that they fail in a similar fashion if there are pre-existing issues. engines that don't typically have HG failures...like the EJ22 will be more random. it will depend on things like which cylinder experienced bad ignition timing, localized heating...etc.

[WAWalker]

there is no difference in the life of a DOHC replaced head gasket and a SOHC replaced head gasket, if properly replaced they should both last the life of the vehicle.

 

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?

 

the real tangent was the "head gasket replacement interval" comment. this likely needs to have a thread of it's own since it is not common practice nor is it mentioned in any FSM, owners manual or considered standard practice on any vehicle, Subaru offers no documentation of this, nor do i recall anyone in the US ever mentioning this. like i already said, the owners manual doesn't mention replacing the headgasket and there's a reason for that.

 

Other than the fact that it is a well documented/proven problem with Subaru engines.

[nipper]

this thread was not started to discusss whether or not the EJ25 has headgasket issues and whether they can or should be replaced as PM. his has already been replaced, he's beyond that point. he's asking about the expected life of a replaced head gasket. with the updated headgasket and properly installed it should not need to be done again.

 

Key word "properly"

 

Thats why iasked what was done before.

 

nipper

[idosubaru]

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.QUOTE] you are correct, that is not a fact. there is no way to base this decision on facts. here's my reasoning. Subaru made a mistake and they know it. the headgaskets of the EJ25 have an issue. i assume that the updated headgasket of the EJ25 is Subaru's best attempt at alleviating that issue. complete assumption on my part, but i'm assuming Subaru is testing things and has some quality control and consumer satisfaction objectives that they want to achive. i'm trusting that they've done their homework and the newer gasket does an excellent job in fixing this issue. and this board offers a very small glimpse into these types of issues as well. we don't see too many repeat head gasket failures, and i've never had one. a certain amount of repeat failures are going to be due to mistakes or poor workmanship, but of course there is no way to verify if that is truely the cause or repeat failures are to be expected. i'm assuming, and that's my personal oppinion to trust Subaur, that they've made significant testing and design improvements on the EJ25 headgasket.

 

Other than the fact that it is a well documented/proven problem with Subaru engines.

we're just talking about different things. i'm speaking on broader terms, that headgaskets are not typical replacement items - see owners manuals of most production engines. think EJ22. all i'm saying is that headgaskets are not replacement items on the EJ2. you are correct, there are problem engines out there where PM HG replacement is a wise thing to do.

[idosubaru]

Key word "properly"

 

Thats why iasked what was done before.

 

nipper

 

agreed. that is certainly the first thing to look at for a head gasket that only made it to 50,000 miles. that was my/the first reply to this thread:

if properly replaced they should never need to be replaced again. the first time around, what brand gaskets were used? it should have been Subaru, if not then that's a possible cause. if not then the shop likely didn't properly clean or torque the head bolts or the heads were not checked and milled.

 

the "PM" HG is pointless in this case.....because his only lasted 50,000. if you want to suggest PM HG replacement as part of his solution, then you'll need to change your numbers to reflect a 40,000 mile interval and i don't think he's interested in that. nipper and i are trying to persue the more obvious issues/concerns he may have.

[WAWalker]

I had used the latest OEM head gaskets. pn 11044AA610

 

heads didn't need to be milled.

 

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.

[Petersubaru]

I am aware of this Well written "needed understanding" and I will bring up in the near future under the old subi forum your suggestion of what others might have to say about the One lose head bolt..

by 1980's do you mean the EA82? the EA82 and EA82T headgaskets should be retorqued. install, torque, run engine to operating temperature. shut it down and tear it all back apart again to retorque the head bolts. Fel-Pro makes a permatorque gasket that is not supposed to require a retorque. they seem to hold very well for the many people on here that use them and recommend them over all others. what gaskets were used and were they retorqued? i do not know why you'd find the bolts loosing torque, that would be an interesting topic for another thread, have you ever asked, i'd be curious to see what everyone says about that? i know the turbo's tend to fail at the rear passengers side cylinder due to heat. there may be other similar contributing factors. the leak starting there and localized heat build up may possibly cause the bolt to loosen or just reduce the gasket material between the head and block, thereby making it seem loose eventhough it hasn't actually "backed out". 'ive seen a number of headgaskets that i've pulled where the headgasket was severly damaged, with much of the material missing, the missing material may put less pressure on the bolt head. it's hard to say which came first.

 

another very important issue which is more evident on the older subaru's you speak of, is the threads. the older subaru's tend to have very corroded and dirty threads when you pull them apart. even engines in good running condition that i've disassembled with no head gasket issues will have corroded bolts. these bolts and the bolt holes need to be meticuloulsly cleaned to make sure they are actually torquing properly. the proper torque, sequence, and retorque means nothing if the bolts holes or bolt threads are not in excellent condition. i clean them and run a tap and die over each bolt and bolt hole when i do my headgasket jobs. for the sake of time, i'd suspect most mechanics do not do that. that being said, EJ engines are typically much newer and fewer miles and do not seem to have the amount of corrosion and dirty threads that i see on the older 80's EA stuff.

 

headgaskets have to be done right to hold. the way they are done makes the difference between them lasting and not.

 

as a side note, with cooling systems in excellent condition, the EA82 will keep it's headgaskets for the life of the vehicle. problem is, after 20 years or a quarter of a century, it's hard to keep a cooling system in excellent condition. with all those years, miles and multiple owners there's just no way to gaurantee the vehicle hasn't been run hot. heat kills gaskets and seals and headgaskets see it up close and personal when it happens.

 

things often fail at the same point. the internal HG, the external HG, the dodge neon HG fiasco, they all fail in similar modes. they will fail at the weakest point of the system, so it makes sense that they fail in a similar fashion if there are pre-existing issues. engines that don't typically have HG failures...like the EJ22 will be more random. it will depend on things like which cylinder experienced bad ignition timing, localized heating...etc.

[WAWalker]

agreed. that is certainly the first thing to look at for a head gasket that only made it to 50,000 miles. that was my/the first reply to this thread:

 

 

the "PM" HG is pointless in this case.....because his only lasted 50,000. if you want to suggest PM HG replacement as part of his solution, then you'll need to change your numbers to reflect a 40,000 mile interval and i don't think he's interested in that. nipper and i are trying to persue the more obvious issues/concerns he may have.

 

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.

[idosubaru]

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.

to each his own should suffice here. none of this was to prove or be right or wrong, that's not my goal. we all work on cars and have differing oppinions and ways of making decisions. when i start seeing replaced head gaskets failing i'll reconsider, but until then it is of no benefit to me to consider something that isn't an issue yet. i'd like to have something more concrete to go on, but i do not.

[WAWalker]

when i start seeing replaced head gaskets failing i'll reconsider, but until then it is of no benefit to me to consider something that isn't an issue yet. i'd like to have something more concrete to go on, but i do not.

 

Post #17 is a start.

[Tech1967]

Maybe the driver rear is the hottest part of the engine and causes that HG bolt to lost tensionson? Maybe a proper job requires complete teardown and block machine? I see more oil leaks on the drivers rear than anything. The block has a lot of real thin surfaces and maybe little local variations in deck flatness won't be caught with the straight edge and feeler guages. Maybe Subaru only pays 6 point something hours to do both gaskets and the repair gets done too fast. I'm willing to suck up lost time for the best job I can do but is everybody else..?

Chrysler had some stuff to spray on their mls gaskets that was supposed to work like a hot damn. On the topic of Chrysler I know that their warranty time for head gaskets was dropped because somebody discovered that they could disassemble a whole lot less, lift the head and dump a gasket in there to make time. They didn't want to pay a whole lot more for these jobs than the guys were taking.

[idosubaru]

Post #17 is a start.

true, that is a start. correlation does not imply causation. at that mileage there's any number of issues that could have caused the HG to go. i do not know who did the work nor how it was done or what maintenance was done/neglected. just as you asked for documentation and proof, i'd want the same from people that have claims of HG failure. i have no way to verify and document that HG jobs were done correctly or their weren't other issues that cause HG failure present before hand.

[Tech1967]

Some kind of good (ie not oil) lubricant between the head of the HG bolts and the washers will allow the washers to seat on the head and the bolt to spin smoothly during the torque process. How many people ignore the pop and jerk and how much does this effect the accuracy of their torque? I've got to admit to doing it a time or two because everything else was looked after (tap & die, cleaning etc.) without it going away. I was never happy enough to stop looking for a solution though.

 

PS No Soobees were harmed during the gathering of data, just Chryslers and they took it well.

[WAWalker]

true, that is a start. correlation does not imply causation. at that mileage there's any number of issues that could have caused the HG to go. i do not know who did the work nor how it was done or what maintenance was done/neglected. just as you asked for documentation and proof, i'd want the same from people that have claims of HG failure. i have no way to verify and document that HG jobs were done correctly or their weren't other issues that cause HG failure present before hand.

 

Ok,

In your opinion, which you are entiltled to, the original gaskets failed do to the fault of the vehicle owner or the gasket itself.

 

And any repeat failure, if the problem was not diagnoised and repair performed by Gary Gross, then the failure was either due to the fault of the owner, or the person who repaired the car.

 

Now I understand were you are coming from. Very bold veiw point.