I know this question has been asked before, but I can't find the thread through a search. Please forgive me for a repeat.

 

So... I think we're considering a new-to-us car. I would love to buy a Legacy GT, but I am still a little leery about the head gasket issue. I know there was a year where they got much better, but can I please know the *EXACT year? I don't want to buy a car and have the HG blow on me. Was it 2005 or 2006?

It got much better in 2005, BUT, there are quite a few 2005 to 2010? that leak.

If you're looking at '05+ Legacy GT's, headgaskets aren't something you need to worry about. Those have the turbo engine that isn't prone to leaking.

If you're looking at '05+ Legacy GT's, headgaskets aren't something you need to worry about. Those have the turbo engine that isn't prone to leaking.

This is the consensus and verified by my friendly SOA tech: Turbo HGs do not leak.

Both of my non-turbo 05's (legacy and outback) experienced the external oil leak from HG which isn't so much of a problem until it starts dripping on the exhaust.

Had the sedan done under extended warranty but will probably wait until the Outback, now with 125k miles, starts smoking like a James Bond smoke screen effect.

I've seen an '06 blow at 97k. External oil weepage.

 

GD

NA head gaskets from '96 through 2010.

The '96-'99 EJ25Ds will blow into the combustion chamber this leading to hydrocarbons (exhaust gases) in the cooling system.

'00 - '04 typically can go over 100k miles before they get bad enough to replace. These leak externally along the bottom side of the heads and block. Usually oil is first, eventually followed by coolant. I have found once I see green coolant on the bottom of the heads or engine crossmember, the heads are more then likely warped.

'05 and up through 2010 usually leak the same as the '00 - '04 gaskets but they go a lot quicker. Usually under 100k miles. Same as above, once I see green coolant, most the time the heads are warped and need to be machined.

So, after the HGs are done, if done properly, how long are they good for?

...most the time the heads are warped and need to be machined.

 

I have to admit that I'm a bit confused about the warped heads.

 

Are the heads warped because:

 

- the head-gaskets have failed, allowing some coolant seepage?

or

- the engine has overheated, causing the head to warp, which in turn caused the HGs to leak?

 

i.e. which comes first, failed HGs or warped heads?

 

Or to put it another way, does engine overheating have to be present for the HGs to fail?

Ok I think I should elaborate.

 

On the EJ25Ds, they get over heated easier as people don't realize they fail internally, until it's too late. Because of the head design on these, they don't usually warp unless they are severely overheated. At that point the heads will crack or warp beyond repair and the block also warps from severe over heating.

 

On the EJ251 and up SOHC non turbo 2.5s, they run a single layer gasket with a coating on them. The coating will eventually get washed out of the bottom starting with the oil passages, then the coolant passages will follow but mileage can vary from 50k to 200k. Depends on routine maintanence and era of the engine. In '05 they were supposedly updated but seem to leak quicker then the older single layer gaskets. When the coating washes out to the point where there is green coolant, the heads are almost warped beyond the .002" spec they should be. It's not from overheating, it's usually from the coating being washed away and from numerous heat cycles. The OEM coating is fairly thick as well so I also think it releases some of the torque on the head bolts in the areas where it washes out.

 

Now don't quote me directly on some of this as its speculation from what I've seen. I typically do a set of 2.5 liter head gaskets of some era at least once a week so I do get to see a lot of different cases.

Turbo's use a much better headgasket and don't have the issue.

Somewhere around 2010 Subaru started using an updated gasket that should "solve" the issue. Allwheeldrive auto has the years if you want to look them up and see their recent video about it- i forget what year it was but it may be the 2010 Caboob just mentioned i guess that's why he mentioned it?

 

So, after the HGs are done, if done properly, how long are they good for?

depends which gaskets are used. if you use the same gaskets that were in there or lesser quality aftermarkets - there's no telling.

 

done properly with the following gaskets should last the life of the vehicle:

 

the DOHC EJ25D's 95-98/99- use the updated 610 gaskets from Subaru

SOHC EJ25's 99/2000+ - use the turbo EJ25 gasket

all subaru engines have head gasket problems always have i'm doing heads on a 06 outback with 90000kms on it leaking oil on exhaust will be the thrid 06 thiss year for headgaskets all under 100000kms as far as i know they still havent fixed the problem the cars just arn't old enuff yet to see how long the headgaskets hold up check the lower ds head seam for oil leaks

the turbo ones dont blow headgaskets because they throw a rod way before they can leak

all subaru engines have head gasket problems always have i'm doing heads on a 06 outback with 90000kms on it leaking oil on exhaust will be the thrid 06 thiss year for headgaskets all under 100000kms as far as i know they still havent fixed the problem the cars just arn't old enuff yet to see how long the headgaskets hold up check the lower ds head seam for oil leaks

DADGUMMIT!!!!

So if this is the case, HGs should be replaced as part of the timing belt interval?

My experience has been that the 105k timing belt interval is a good choice for a preemtive HG replacement.

 

In the vast majority of cases that policy would save people a lot of money and wasted time/effort.

 

And... in the vast majority of cases... people will not avail themselves of my sage advice and will end up losing the gamble.

 

I see this on a routine basis and it's no longer surprising to me. I can complete people's sentances over the phone when this subject arises. It's like reading a familair old script.

 

GD

My experience has been that the 105k timing belt interval is a good choice for a preemtive HG replacement.

 

In the vast majority of cases that policy would save people a lot of money and wasted time/effort.

 

And... in the vast majority of cases... people will not avail themselves of my sage advice and will end up losing the gamble.

 

I see this on a routine basis and it's no longer surprising to me. I can complete people's sentances over the phone when this subject arises. It's like reading a familair old script.

 

GD

 

This... Pretty much sums it up. If they're not leaking badly and are still OEM, replace them with the timing belt.

i agree i think the timing belt would outlast the headgaskets in most cases what your missing is how mutch damage the block and head surfaces get from running with a blow headgasket the last block i planed took 4 thow just to remove the burn away from around the cly and most take anywhere from 2-6 thow to get a clean surface the longer its gone the more damage and when you do gaskets the block surface is uhasly to bad to get a prefect seal so repeat headgasket failure is commen i do headgaskets rods mains rings and block and head surface now on everyone thats over 150000kms or been runing with blown head gasket just to cover my butt they work good and very few combacks

Then a question to ask is are the turbo HG the same pattern as NA? If so throw some turbo gaskets up there.

Use the 11044AA642 turbo head gaskets.

turbo one look like same ones little bitt different but same thing the turbo blocks are stronger so that helps still a weak gasket just a stronger block less prone to warp or cly walk[ yes cly walk ] witch is the main headgasket problem the barrels move and tear the headgasket back and fourth till it fails turbo ones have 4 added block supports to prevent thiss

turbo one look like same ones little bitt different but same thing the turbo blocks are stronger so that helps still a weak gasket just a stronger block less prone to warp or cly walk[ yes cly walk ] witch is the main headgasket problem the barrels move and tear the headgasket back and fourth till it fails turbo ones have 4 added block supports to prevent thiss

 

Not all turbos do. EJ205s still run an open deck block but the EJ255 and EJ257 run a semi closed deck because of the bracing you're talking about.

2.0 make me sick what a waste of time useless moters good for crank and heads [ no replacement for displacement ] i see thiss evrytime a big block kicks my subarus rump roast 502 bb aginst 2.5 subaru is a good example mind you i'm only 2 seconds of there time