Author Topic: Head gaskets, and you (Read 8137 times)

seat safety switch · « **on:** November 20, 2012, 01:38:06 pm »

One of the forums I read has an excellent FAQ about Subaru headgaskets which I now dump in its entirety here, because people ask me:

Quote

The subarus that have had problems with them are the N/A 2.5l cars. Have an EJ22? It probably won't break. The first EJ25s were especially bad, so if you're looking at a 96-99 2.5 impreza or legacy make sure they have been changed. Subaru has finally made a new gasket for the cars that will be trouble free (a thicker sti gasket- pn 11044AA610), but it is only for the phase 1 motors.

If you have a 99-09 n/a Subaru it also has crappy headgaskets, and if you go to the dealership for gaskets they will install those same crappy ones. Thankfully there is a solution to this problem- 04-06 STi headgaskets. The are the same thickness, have all the holes in the same places, but are a multi layer steel (MLS) design, compared to the junk single layer coated gaskets. Part number is 11044AA642.

For 2010 the n/a subarus finally got a MLS gasket which is pn 11044AA770, or the same gasket in the 2008+ STi. The only difference between this gasket and the -642 are the holes for the cooling passages in the head.

So to summarize
if your phase 1 2.5 needs headgaskets get 11044AA610
if your phase II 2.5 needs headgaskets MAKE SURE to get 11044AA642. The dealership will not give you these gaskets if you give them your VIN.

Now that we're starting to see 04-05 headgaskets failing it's worth reading up!

Motohead · « **Reply #1 on:** November 21, 2012, 12:30:16 pm »

hot damn, you'd think Subaru would have learned thier lesson with the phase 1 2.5s and gone MLS across the board.

Maybe a production consideration I am not seeing, such as surface tolerences needed for MLS (not to mention the extra cost of an MLS gasket).

Knock on wood I've never had HG issues on any Subaru I've owned including my 98 LGT back in the day, nor had it affected any of my friends/family subbies. No where have I seen hard stats on HG failure rates, maybe it's more common than the industry standard, but still a relatively rare occurance? Hmmm...

Jack_Cracker · « **Reply #2 on:** November 21, 2012, 12:34:13 pm »

I notice the EJ20 isn't mentioned.
Does this mean we're safe?

Motohead · « **Reply #3 on:** November 21, 2012, 12:40:07 pm »

NO ONE IS SAFE!

MWWUUUHAHAHAHA!

Seriously tho, I don;t hear of HG's going as I do on 2.5s, unless it's high boost/ tuning error related. All I have heard popping for no good reason is just 2.5 HGs. Totally antecedal hearsay, I have no (thankfully) first hand experience with HG issue.

gd8 · « **Reply #4 on:** November 21, 2012, 01:08:29 pm »

The 2L on 04 are Multi Layer Steel gaskets. Safe??? who knows. I ripped my block apart and noticed one end of the gasket was showing signs of coolient starting to work it's way in. At that time my engine was only stage 2.

seat safety switch · « **Reply #5 on:** November 21, 2012, 01:12:12 pm »

WRXes are safe(r), they use an MLS gasket.

This thread is primarily for NA engines, which is why it's in the NA subforum

teacherman · « **Reply #6 on:** November 21, 2012, 01:30:10 pm »

DOHC NA engine were brutal for blown HG's. This is why I got such a smoking deal on my LGT.

Jack_Cracker · « **Reply #7 on:** November 21, 2012, 01:30:44 pm »

Ahh yes. My bad, wasn't looking up there at the thread location.

gd8 · « **Reply #8 on:** November 21, 2012, 01:57:05 pm »

^ Yeah Jack, guilty by association... Jack's falult

AWDFTW · « **Reply #9 on:** November 21, 2012, 07:14:40 pm »

When you use the sti gasket do the torque specs on the head bolts change?

teacherman · « **Reply #10 on:** November 21, 2012, 07:51:39 pm »

Quote from: AWDFTW on November 21, 2012, 07:14:40 pm

When you use the sti gasket do the torque specs on the head bolts change?

I don't think it would. The size of the bolt doesn't change.

Guglianoh · « **Reply #11 on:** November 21, 2012, 10:16:25 pm »

Quote from: Motohead on November 21, 2012, 12:40:07 pm

NO ONE IS SAFE!

MWWUUUHAHAHAHA!

yup
had my HG go on my 94 WRX at 98xxx km but HG issues doesnt seem to be as big an issue on the turbo variants as they are on the NA

Quote from: AWDFTW on November 21, 2012, 07:14:40 pm

When you use the sti gasket do the torque specs on the head bolts change?

if u re-read the quote from the OP it says the gaskets are the same thickness only different construction, torque will not change

redblack · « **Reply #12 on:** November 21, 2012, 10:28:17 pm »

I just replaced mine last week with the 642 gasket, no more oil drips on my 2005 impreza. The job itself is not that hard, 4 hours to teardown, 1 day for the machine shop, 2 hours to clean up the block and another ~5 to re-install.

Jimmy@Vex · « **Reply #13 on:** November 22, 2012, 03:10:27 pm »

Quote from: teacherman on November 21, 2012, 01:30:10 pm

DOHC NA engine were brutal for blown HG's. This is why I got such a smoking deal on my LGT.

I got raped on my OB. I paid prime dollar and then the HG went a week later.

I machined .002" off the heads and I'm running STi HG's now. Runs great!

flyboynextdoor · « **Reply #14 on:** December 01, 2012, 06:22:55 pm »

Bad HGs is how I picked up my RS for $400, fixed the engine for another $400!!!

klatch · « **Reply #15 on:** June 02, 2015, 03:19:25 pm »

Quote from: seat safety switch on November 20, 2012, 01:38:06 pm

If you have a 99-09 n/a Subaru it also has crappy headgaskets, and if you go to the dealership for gaskets they will install those same crappy ones. Thankfully there is a solution to this problem- 04-06 STi headgaskets. The are the same thickness, have all the holes in the same places, but are a multi layer steel (MLS) design, compared to the junk single layer coated gaskets. Part number is 11044AA642.

Is this still the current lay of the land? My headgaskets aren't leaking at the moment but I'm keeping an eye on them. On speaking with Apex Specialized (shop in Edmonton) they told me that they use the factory gaskets, though I believe they said they are updated. I'm not sure if they were updated since this was posted, or if they were updated to MLS, or if I should still insist on the STI headgaskets if/when I need to replace them.

seat safety switch · « **Reply #16 on:** June 03, 2015, 10:24:39 pm »

Quote from: klatch on June 02, 2015, 03:19:25 pm

Is this still the current lay of the land? My headgaskets aren't leaking at the moment but I'm keeping an eye on them. On speaking with Apex Specialized (shop in Edmonton) they told me that they use the factory gaskets, though I believe they said they are updated. I'm not sure if they were updated since this was posted, or if they were updated to MLS, or if I should still insist on the STI headgaskets if/when I need to replace them.

I can't speak to what Apex uses.

I would insist on the MLS STI headgaskets.

AdrenalineXI · « **Reply #17 on:** July 26, 2015, 02:13:28 pm »

My '06 NA 2.5L Impreza is leaking oil all over my garage floor. I've just topped up oil to this point. IF I was to get someone else to fix it, does anyone have any recommendations in Edmonton? I've done timing belts, but head gaskets seem a bit out of my league.

Any advice?

gd8 · « **Reply #18 on:** July 26, 2015, 02:27:44 pm »

You have to find the source of the oil leak. Oil leak from head gasket is unlikely and not common.

seat safety switch · « **Reply #19 on:** July 26, 2015, 03:05:59 pm »

It is almost certainly your valve cover gasket, which is a common (if finicky) procedure. You can easily DIY that job.

snackers · « **Reply #20 on:** July 26, 2015, 09:13:30 pm »

While an HG oil leak may not be common, it does happen.
Mine is doing it right now.
Another forester sohc had it happen last year.
Valve covers were clean and shiny and spotless.