Hi, I disassembled my motor and I'll putting in the new head gaskets soon. It's on a '97 Legacy GT 2.5 motor. Anaerobic seal, copper spray or nothing? What do you guys do and what do you recommend?

 

I got the following sealers, all permatex:

Ultra Grey - intake manifold, little bit on the valve covers and cam brackets, thermostat housing, anywhere else?

 

Water Pump RTV silicone - for the water pump gasket, I bought a subaru gasket - I read to use the ultra grey though, not sure which one to use yet.

 

Blue Threadlocker - cam bracket bolts or just some motor oil?, cam cover bolts, just about all the bolts except the head bolts.

 

This is my first major engine repair job, so all input is appreciated.

Thanks.

Edited September 10, 201015 yr by 86GLScooby

I never use anything on the head gaskets. Using a good quality gasket is all you should need as long as the heads and block are flat. I tend to go aftermarket, but I also build for rally or turbo applications, that might be overkill for you.

 

As for the other bits & pieces, just follow the service manual suggestions. If you can't find a service manual for that engine you can use one for the turbo engine, the differences would be in torques and such, not in sealing materials.

 

If you don't have a manual to give you the torque specs and sequences, you will need to get them, they are quite important to success.

 

Keep a clean work area and take your time. It's not that hard and is very satisfied when it's a job well done.

On any 2.5 use SUBARU head gaskets, installed 100% dry. No sealer or sprays of any kind whatsoever. If you use a sealer, you'll be changing the gaskets again in a month.

After market gaskets are hit or miss, it might work great, or it might fail in 500 miles. But either way you go, the biggest factor in how long the gasket lasts will be how flat the heads are, how clean the sealing surfaces on the head and block are, and making absolute certain that you follow the proper torque procedure.

 

For the water pump gasket. Use Indian Head shellac compound.

Most parts stores carry this, its usually less than $5.

ALL GASKETS INSTALLED DRY!!!!!!!

 

 

YES - WATER PUMP TOO.

 

Dealer gaskets do not require any sealant and you will just make a mess and comprimise the seal if you do that.

 

Do not use the threadlocker either. You don't need it. That is for very specific applications. ESPECIALLY do not use threadlocker on the head bolts!!!!! I will personally come over there and kick you square in the nuts.

 

GD

Don't kick me in the nuts... I actually realized that I typed that after I had my coffee and edited it after getting back from autozone... can't believe I typed that... you just put some motor oil on the head bolts. As for taking my time... yes, I'm on day 5 and I'm just getting to the head gaskets. Bagging and tagging everything as I go along. Learning the hard way on some stuff, but that's okay. This is take forever though... can't wait to be done, but I'll take my time.

 

Now, the water pump gasket, this is from subaru, for some reason it doesn't lie flat of the ground like it's warped or something. I don't know if it's defective or what, but I think I'll put some sealant on that one perhaps. Or use the bent up cardboard one that came with the pump... lol, no I won't do that.

 

I have the tork info, so that should be okay... aspecially the head gasket sequence.

 

Thanks for your comments and I won't put anyting on the subaru head gaskets... as for the other stuff I'll follow the manual.

 

I appreciate your comments, thanks.

Now, the water pump gasket, this is from subaru, for some reason it doesn't lie flat of the ground like it's warped or something.

 

they are or have some metal in them, don't worry. just install it dry and torque all the bolts to spec. you'll be good.

 

unless it is kinked, then get a replacement.

This thing is a beast... I've been spraying the exhuast bolts under the heads with PB Blaster for 3 days now and they still won't come off. Any advice? Bottom of the bolts are realy rusty. Put my breaker bar on it and I can see that they are stripping, but I don't want to over do it... seems like a bad design, why don't they use bolts? (becuase the head is aluminum) Tried tightening them a little and then loosen, nothing.

 

Researched and found the helicoil method and some others... really? Do I cut the studs off if I can't get the nuts loose or what?

Edited September 10, 201015 yr by 86GLScooby

Thought I got one off, but it actually unscrewed from the head... Got 3 off out of the head and 3 stripped... 50% success rate. But it's still a fail. Update, got 5 out and one is totally stripped... need the bolt out tool.

 

Welcome to the club?

Edited September 10, 201015 yr by 86GLScooby

Heat is your friend on those exhaust bolts.

 

Never stripped one. Have broken a few off though.

 

Make sure to use a wire brush to clean the threads off before you try and remove the nut. Sometimes the nut breaks loose than hits all the crap in the crappy threads then it has problems.

 

As has already been stated all gaskets dry.

 

Hope you're resealing the baffle plate while it's out with the Ultra Grey. If you're doing the oil pump it gets Ultra Grey too.

All the OEM water pump gaskets are warped like that - it's from the punching/deforming process they use to create them. They are fine - just torque it down and it will be ok. No need for sealant - they are rubberized anyway.

 

GD

I thought about the ole plumbers trick, if it's stuck heat it up... but I wasn't sure about that with all the flamable fluid around. I don't mind buying new studs if I can just get this last one out. I would assume they break easier when heated?

i think less than %50 of the nuts come off for me. i'm surprised dave gets them out, his rust should be about what mine is. i expect the entire stud to come out with it most of the time.

 

i've never had a problem getting one out though - have you used a socket and wrench - what happens? it's rounded off?

 

heat is always useful...used appropriately of course.

I clean the threads after the nut. Then I get about 50/50 nuts versus studs. I don't care I just mark them so I know where they go back and am liberal with the anti-seize. BTW those nuts are also what's used on the engine mounts and exhaust. And they are coated and kinda pricey for just a nut. Therefore I have some new ones on hand and a drawer full of nuts and studs from cars I've scrapped.

 

I usually break them loose with a long snap-on breaker bar. Then run them off with the IR impact. Don't know if hitting them with the serious IR 1/2 Impact first may be the way to go or not. I seem to like to "feel" bolts when they snap, rather than just wondering what happened with a gun. Then again I guess the repair is the same. Just don't know which way increases the odds of not breaking the bolt.

Davebugs. I must agree to your incite about breaking loose bolts. I too would like to feel them "snap" loose. The armory many have when one is embedded in a head or operation is to use varying impact upon them if at all possible.

Sorry for the 2nd reply but I'm always timed out. The side load from a breaker is different. I've broken things. Also, You most recently has addressed cleaning the threads of junk so a loosened fastener has somewhere to go without binding. This is valuable. Maybe some won't have the bad habits we saw before which is in early stages.."the stud came out".

Had the same problem with my first head gasket job on an impreza. About half the exhuast nuts came off.

 

Heat is your friend. Heat the stud and the head around it, then use the impact gun. You are more likely to break off the stud with a long breaker bar.

 

I went through 2 harbor freight impact sockets before the last stud came out.

Thanks for the replies, I did get the final stud out. It's propably better that the studs came out so I can replace them... make the job easier the next time. Hopefully only in a 100k or so.

Wanted to bring up the headgasket issue/question again. I've heard some comments in the positive about using a copper gasket spray on both sides of the head gasket. This was primarily being discussed about the ej22t motor, and other built motors, so likely the 2.5 out of the STi.

 

I'm not sure if the motor type changes anyone's recommendation, I just wanted to throw that out there and see if the feedback is the same....

 

Thanks

Got a little more info on the recommendation for the copper spray. It was specifically for the Cometics head gasket.

 

"The theory is that surfaces that are not freshly machined will have variations that the thin layer of Viton on the Cometics struggles to conform to. The Permatex Copper Gasket Spray can take up those variations."

 

Since I'm just using the carbon stock head gasket, I won't bother with any copper spray, and just install dry.

I've used the copper spray on the last couple of HG jobs I've done.

A couple of EA82T's and a EJ22T.

Never blew a HG after using the spray, just the ring lands on the EA82T's

I have metal HG on the EJ, so I thought it would be a good idea to use it there also.

Any of them that look fiberous on the HG I use copper spray. Any that are solid metal I never do.

I don't think its absolutely necessary to use copper spray either. They are pretty good gaskets as they are.

Well I put the heads on this past weekend, and didn't use any copper spray. So hopefully it holds up well. I don't want to be doing head gaskets again.