attempting a head gasket job

[bgambino]

I bought a 98 Outback wagon with supposed blown head gaskets

It overheats

Funny,...it seems to lack power....is this normal for blown HG's?

Also has check eng light

I took out the 2.5 engine.

Before taking heads off I have some questions

 

--do I have to keep the cam shaft and accessories arranged so they go back in the identical spot (I'm not sure what parts there are going to be)...do the lifters have to go beck into here respective spots or does it matter if they get mixed up

---any way to soak and clean out the lifters or is that not a good idea?

--Do I have to follow the tightening sequence in reverse when taking heads off?(loosen bolts little by little?)

 

I'm trying to figure how much to do on the engine

Would it be advisable to do the front and rear engine seals?

I plan on doing timing belts and cam seals & valve cover gaskets

--water pump

--should I replace the oil pump?..or just the o-ring thing (I'll ask about this procedure later)

--also figured I change the crank pulley as I've read here that they have some kind of rubber inside that deteriorates

WHAT ELSE?

Thanks guys

Bill

[nipper]

When in doubt, everything goes back to where it came from. Unless your replacing the lifters, i would put them back in there happy homes. Same goes with all the other parts, except the cyl head bolts.

i usually get new lifters if the engine has a lot of mileage on it, so i cant answer you there. i would strongly suggest NOT cleaning them.

Use the pattern in the manual (Haynes) for re torqing the bolts. This is a critical step and has to be done as stated.

You do the cam seals, main front and rear seals. re seal the oil pump. Replace the water pump and the timing belt tensioner. Of course the timing belt gets replaced. Rule of thumb is if its buried and prone to wear, you replace it while the engine is out. Use new radiator hoses and do an oil change (oil gets damaged from over heating too)

The surfaces for the HG have to be so clean they are almost sterile.

Hope that helps.

 

nipper

[svxpert]

<<i usually get new lifters if the engine has a lot of mileage on it, so i cant answer you there. i would strongly suggest NOT cleaning them.>>

 

2.5 DOHC heads do not have lifters....

[nipper]

<<i usually get new lifters if the engine has a lot of mileage on it, so i cant answer you there. i would strongly suggest NOT cleaning them.>>

 

2.5 DOHC heads do not have lifters....

 

sure quote me instead of the original poster . i stand by what i said, last sooby engine i took fully apart had hydraulic lifters.

 

nipper

[a97obw]

My suggestions:

 

1) At least purchase a Haynes manual

2) Buy, beg borrow or steal a digital camera and take LOTS of pictures before you disassemble the engine

3) See #1

3a) Check the valve clearances if this engine like the 97 has a shim type valve clearance adjustment BEFORE you take everything apart.

4) Get a BUNCH of zip lock baggies. Make a sketch of the lifters on several small pieces of paper. Use something like a blue sharpie to draw the intakes and a red sharpie for the exhaust on your sketches. Place a marked up sketch with each lifter assembly and it associated lifter assembly in a plastic bag. Put all the intake baggies from one side of the engine in a larger baggie. Do same for the exhaust baggies. Make another sketch of the camshaft caps and where they belong. Tag and bag these as well. NOTE: do NOT screw up the order or orientation of the camshaft caps! You want horror stories about this? They are on this message board! Put all this stuff in an even larger baggie that will also contain the cams themselves.

5) Work area must be like a hospital. Clean, clean, clean!

6) See #1

7) Keep the head bolts organized from where they came from. A small piece of cardboard with a sketch of the flywheel on one end, then poke a hole through the cardboard will suffice to hold the bolts. One at a time, clean the threads of the bolts so they take up in the case without any tight spots. You want to try and get rid of that "CREEEEEEEEEAAAAAKKKK" noise that you will hear when you remove the heads.

8) Get some camshaft assembly lube to use when you put it all back together. I bought some at O'Reillys that was in a little white bottle. Red and would adhere to the parts pretty good. Use PLENTY of this. "Mellube" made by Melling. Yeah, thats the stuff!

9) The camshaft caps in the center and the rear with the larger bolts get torqued to like 14.5 ft. lbs. Careful, they MIGHT break! The smaller bolts in the front camshaft cap get torqued to only like 7 ft. lbs. This you WON'T find in the Haynes manual OR the Factory Manual. They will both tell you 14.5 ft. lbs and guess what.....you WILL break those bolts hopefully before you pull the threads out of the aluminum heads!

10) See #1

11) IF you have the heads machined, clean clean clean them up GOOD. Blast out the oil passages to the lifters with compressed air followed by WD 40 via the straw on the can. Repeat several times. Trash in the passages is a sure fire way to DESTRUCTION! Again, the stories are on the message board!

13) See #1

14) I skipped 12 for a reason. I forgot what it was. (the suggestion, not the reason.)

15) Allow PLENTY of time to do the procedure. Aint gonna happen CORRECTLY in a day if it is your first time to do it. A LOT of time you will be cleaning parts, so count on that.

16) See #1.......and also it appears the Chilton version of the head bolt torque sequence is WRONG!

17) A storage building complete with electricity and the bottom from the broken office chair you leaned back too far in one too many times, along with a pallet on your engine hoist makes for a great working space. (Note #1 in left foreground of pallet!)

 

 

Good Luck!

[bgambino]

My suggestions:

 

1) At least purchase a Haynes manual

2) Buy, beg borrow or steal a digital camera and take LOTS of pictures before you disassemble the engine

3) See #1

3a) Check the valve clearances if this engine like the 97 has a shim type valve clearance adjustment BEFORE you take everything apart.

4) Get a BUNCH of zip lock baggies. Make a sketch of the lifters on several small pieces of paper. Use something like a blue sharpie to draw the intakes and a red sharpie for the exhaust on your sketches. Place a marked up sketch with each lifter assembly and it associated lifter assembly in a plastic bag. Put all the intake baggies from one side of the engine in a larger baggie. Do same for the exhaust baggies. Make another sketch of the camshaft caps and where they belong. Tag and bag these as well. NOTE: do NOT screw up the order or orientation of the camshaft caps! You want horror stories about this? They are on this message board! Put all this stuff in an even larger baggie that will also contain the cams themselves.

5) Work area must be like a hospital. Clean, clean, clean!

6) See #1

7) Keep the head bolts organized from where they came from. A small piece of cardboard with a sketch of the flywheel on one end, then poke a hole through the cardboard will suffice to hold the bolts. One at a time, clean the threads of the bolts so they take up in the case without any tight spots. You want to try and get rid of that "CREEEEEEEEEAAAAAKKKK" noise that you will hear when you remove the heads.

8) Get some camshaft assembly lube to use when you put it all back together. I bought some at O'Reillys that was in a little white bottle. Red and would adhere to the parts pretty good. Use PLENTY of this. "Mellube" made by Melling. Yeah, thats the stuff!

9) The camshaft caps in the center and the rear with the larger bolts get torqued to like 14.5 ft. lbs. Careful, they MIGHT break! The smaller bolts in the front camshaft cap get torqued to only like 7 ft. lbs. This you WON'T find in the Haynes manual OR the Factory Manual. They will both tell you 14.5 ft. lbs and guess what.....you WILL break those bolts hopefully before you pull the threads out of the aluminum heads!

10) See #1

11) IF you have the heads machined, clean clean clean them up GOOD. Blast out the oil passages to the lifters with compressed air followed by WD 40 via the straw on the can. Repeat several times. Trash in the passages is a sure fire way to DESTRUCTION! Again, the stories are on the message board!

13) See #1

14) I skipped 12 for a reason. I forgot what it was. (the suggestion, not the reason.)

15) Allow PLENTY of time to do the procedure. Aint gonna happen CORRECTLY in a day if it is your first time to do it. A LOT of time you will be cleaning parts, so count on that.

16) See #1.......and also it appears the Chilton version of the head bolt torque sequence is WRONG!

17) A storage building complete with electricity and the bottom from the broken office chair you leaned back too far in one too many times, along with a pallet on your engine hoist makes for a great working space. (Note #1 in left foreground of pallet!)

 

 

Good Luck!

Thanks ao97obw

I read Haynes and also bought Chilton (do not like the CHilton at all)

Someone posted a link to "Endwrench" for the timing belt job--this was very good and seemed concise

I've replaced enough timing belts on the GL's and Loyales that it's a snap (never did HG tho)

I have the engine out of this 96 Legacy 2.5 to do a head gasket job and the more I read the more ominous it sounds

I think this is a twin cam...?

Does this have the shims in the valve area? If so, what does that mean for me when disassembling (I don't even want to confuse things by asking about the shims and the assy. process now)

One of my concerns is whether I need some special tools for this job:

special crank pulley (holding) wrench?

there are 2 different tools recommended by "Endwrench" to hold the cam sprockets...they make it sound like you better have them or valve damage will occur...?

Assuming I line up the crank to TDC on comp stroke (BTW, Haynes did not specify the front or rear of the motor when they show a diagram of the firing order--is #1 the rear pass plug?), I'm worried about the cam moving when the belt tension is released (valves colliding per endwrench)

[idosubaru]

you don't need any special tools. there is information on here about holding hte cam sprockets in place.

 

definitely replace front and rear seals at a couple dollars each no big deal. no need to replace the oil pump, just the seal.

[Gnuman]

Thanks ao97obw

I read Haynes and also bought Chilton (do not like the CHilton at all)

Someone posted a link to "Endwrench" for the timing belt job--this was very good and seemed concise

I've replaced enough timing belts on the GL's and Loyales that it's a snap (never did HG tho)

I have the engine out of this 96 Legacy 2.5 to do a head gasket job and the more I read the more ominous it sounds

I think this is a twin cam...?

Does this have the shims in the valve area? If so, what does that mean for me when disassembling (I don't even want to confuse things by asking about the shims and the assy. process now)

One of my concerns is whether I need some special tools for this job:

special crank pulley (holding) wrench?

there are 2 different tools recommended by "Endwrench" to hold the cam sprockets...they make it sound like you better have them or valve damage will occur...?

Assuming I line up the crank to TDC on comp stroke (BTW, Haynes did not specify the front or rear of the motor when they show a diagram of the firing order--is #1 the rear pass plug?), I'm worried about the cam moving when the belt tension is released (valves colliding per endwrench)

 

OK, is this a 96, or a 98?

 

if it is a 96: you have hydraulic lash adjusters and should have no clearance on any of the valves.

 

If it is a 98: you have the same type of shims as the 97.

 

Both: take your time, put everything back where you got it. mark the tops of the shims with a sharpie indicating which cyl, intake or exaust, front or rear (there are two of each valve on each cyl). The cam caps are already marked, but be sure they go in correctly (right side up).

 

Yes, you need to loosen the bolts 180 degrees using the tighterning sequence, then annother 180. By this time it should be finger tight or less, and you can take them out at that time. I recomend taking the oil pump off and tightening the screws on the backing plate, as they work thier way out over time. The front seal should be replaced at this time, along with O-ring, and the 4 cam seals.

[nipper]

He said its a 98 as i got corrected once on the lifters .. grrr

 

nipper

[bgambino]

OK, is this a 96, or a 98?

 

if it is a 96: you have hydraulic lash adjusters and should have no clearance on any of the valves.

 

If it is a 98: you have the same type of shims as the 97.

 

Both: take your time, put everything back where you got it. mark the tops of the shims with a sharpie indicating which cyl, intake or exaust, front or rear (there are two of each valve on each cyl). The cam caps are already marked, but be sure they go in correctly (right side up).

 

Yes, you need to loosen the bolts 180 degrees using the tighterning sequence, then annother 180. By this time it should be finger tight or less, and you can take them out at that time. I recomend taking the oil pump off and tightening the screws on the backing plate, as they work thier way out over time. The front seal should be replaced at this time, along with O-ring, and the 4 cam seals.

 

Okay,,,my mistake--it's a 96

thanks for all the advise

Does anyone know of a post or 2 that discusses how to hold the cam sprockets so as to take off timing belts?

Once the T belt is off...do I leave the cam sprockets clamped while loosening the cam cap bolts?

[a97obw]

1) Consult the new Haynes manual you just bought to do this job. You did buy the manual, correct?

 

2) Use a chain wrench to hold the front crankshaft pulley and a socket with long extension to break the pulley loose. Remove pulley so you can remove the front center plastic timing belt cover. After removing the cover, put the pulley back on, and just snug the bolt so you can turn the engine over clockwise in order to line up all the timing marks.

 

3)Remove valve covers and using a very large crescent wrench find the spot on the camshafts that has a hex figure cast into it. Hold the camshaft with the crescent wrench on the hex in order to break the camshaft pulleys loose.

 

4) Don't worry about a camshaft "holding tool". Just don't turn anything after taking the belt off.

 

You can figure the rest out........

[nipper]

4) Don't worry about a camshaft "holding tool". Just don't turn anything after taking the belt off.

 

quote]

 

Allow me to introduce you to my freind Murphy .....

 

nipper

[Gnuman]

I also say not to worry about the camshaft holding tool, but once you have the cam cover off, use a 25mm open ended wrench to turn the cam so it turns a bit freely. At that point, the valves will be all the way closed, and are not in danger. This will have to be done anyway, as you will have to remove the cams in order to access the head bolts. take things slow, and go step by step, and you will be fine. Remember: 14ft-lbs on the rear cam caps, and only 7ft-lbs on the front ones that also hold the cam seals.

[roger1]

My OEM belts had marks on them to help with timing. Sure made it easier, when I turned the engine through it was right on! Has anybody found marks on after markets ones like Gates? I used some webbing over pulley when I used the chain wrench as I had to file kicks off I made during removal.