Head gasket job

[Pridian]

Hey all, I’m a teacher- so I’m off for the summer. I’ve been losing coolant at an alarming rate, so I’m looking at pulling the engine this summer.

Just a few questions for anyone who’s successfully completed the job.

1) I’ve done the timing belt- so how difficult is the head gasket job comparatively?

2) I’m assuming, from everything I’ve read, that I need to pull the engine. I’ve never pulled an engine before. While it’s out, I’m looking at replacing rear main seal and all that jazz as well. Are there any kits that anyone recommends for these gaskets/seals? I know Felpro for the head gasket.

3) I haven’t overheated to my knowledge. I know that you always want to machine the heads, so does anyone know of any good machine shops in SWFL? I’ve been searching and nothing to show for it- so I was just wondering if anyone has any experience.

4) lastly, I know there are a ton of videos on the matter- but I was wondering if anyone has made a write up.

Thank you for all of your help!

[KZJonny]

Welcome to the site! I'm never shooting us in the foot, but I would also spend some time at subaruoutback.org there is a LOT more info on the 2.5i NA platform than here, where the focus is very much on turbochaged engines.

There is a write up here somewhere. Google site search here is far better than using the build in serach function. I'll see if I can dig that up. It was pretty in depth, and possibly more work than needs to be done.

1 - It's a lot more work, but if you have a good tool chest and time (you said you have time) then it's totally reasonable. Remembering that you're opening the engine, so cleanliness become paramount now. Thing I learned the hard(sish) way, you'll save a lot of time later if you wash the engine thoroghly in the engine bay with the accessories off, then again when it's on the engine stand before removeing the heads etc.. 2.5i is MUCH easier to do a head gasket job than the EJ255/7 Just less junk in the way.

2 - Probably easiest to pull the engine, yeah. Not a hard job, but if you can beg/borrow an engine hoist + stand, your back will thank you. A LOT. I am 99% sure I got a kit from Mahle that had most of the top end gaskets I needed including head gaskets. As long as they are MLS and not the coated OE style, you should be fine. I didn't bother with the rear main personally, since they're not known to fail on these engines, but my all means do it. They are cheap, and it's preventative.

3 - If not overheated, you have options. This is not a high performance engine, tho not a slouch either. Many have just cleaned the heads + block surface (+/- copper gasket spray....) thrown in new gaskets and been on their merry way. I sanded the heads myself at home using a sheet of glass and sandpaper glued down flat to it. Probably took me half a morning and saved a few hundo. When I did my GT rebuild, I went to the machinist, but NA vs. 18psi of boost is a BIG difference in how much it matters.

 

If you fail on finding one of the several guides/walk throughs on here, someone will circle back and help out.

 

[rhino6303]

A few things first.

1. How do you know it's the headgaskets?

2. Buy a pressure tester and use it to find leaks.

3. Buy a hydrocarbon test kit for the headgasket.

You'll save money in the long run this way.

[KZJonny]

1 hour ago, rhino6303 said:

A few things first.

1. How do you know it's the headgaskets?

2. Buy a pressure tester and use it to find leaks.

3. Buy a hydrocarbon test kit for the headgasket.

You'll save money in the long run this way.

You are not wrong.

But there are two kinds of EJ253's. Those that have had a head gasket job done, and those that need to have one done soon. I agree, it would be wise to check, but if it isn't dripping coolant and it's losing a bunch, it's a pretty clear indication on these engines that the head gaskets are failing.

They all fail around 250k kms. I've done a couple now, mainly external leaks, but still... Unless you known for sure that the heads have already been done on an NA 2.5i, doing them is practically preventative maintentance.

Edited June 4 by KZJonny

[rhino6303]

18 minutes ago, KZJonny said:

You are not wrong.

But there are two kinds of EJ253's. Those that have had a head gasket job done, and those that need to have one done soon. I agree, it would be wise to check, but if it isn't dripping coolant and it's losing a bunch, it's a pretty clear indication on these engines that the head gaskets are failing.

They all fail around 250k kms. I've done a couple now, mainly external leaks, but still... Unless you known for sure that the heads have already been done on an NA 2.5i, doing them is practically preventative maintentance.

That is true (did this on my ej253 at 100k miles) but there are so mamy places for coolant to go without seeing dripping that it's easy to test first before tearing out an engine.