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Old 02-14-2007, 06:02 PM   #1
Scooby Newbie
Member#: 138806
Join Date: Jan 2007
Default 2.5 head gasket replacement in car





This is a general write up and no way guarantees success in doing this job. Do this job at your own risk. There may be a few things that need to be removed that is not mentioned here, but it should be minor. I will not be held responsible for and trashed engines.

Good luck

I know some of you guys prefer to do head gasket replacement by yanking the engine out, but I just did mine without removing engine and found it not that difficult. ( I had no engine hoist).

First, pull you car up on ramps or jack the front end up. Disconnect the battery. Unplug the two O2 sensors and remove the y-pipe. This will open up the area under the car.

Then remove that battery, windshield washer fluid container, air cleaner stuff including air box in back of engine to throttle body.

Drain coolant and disconnect radiator hoses and transmission hoses (if applicable)

Disconnect cam position and crank sensors.

Remove a/c and alternator belts.

Unbolt air intake and suspend with bungy cord from car hood. You will have to remove spark plug wires from spark plugs. And there are some hoses and egr tube to disconnect to lift the intake up. You donít have to lift it up very high, just high enough to get yourself some room.

Remove alternator.

Unbolt power steering reservoir and lay it to the side.

Unbolt a/c compressor BRACKET and suspend with bungy cord from the hood.

This should open up everything you need for removing heads.

Next, take off the two outside timing covers.

Now take off the crank pulley. I stuck a screw driver into the flywheel to break the bolt free. Once the crank pulley is off, remove the last timing cover to expose the timing belt.

Now put the bolt back in the crank shaft and turn the engine over until all timing marks are aligned. I am assuming that you have a service manual of some kind. If you donít, get one.

To break the cam shaft pulley bolts free, I again jammed a screw driver to the flywheel, held tension on belt and all four bolts broke free easily. Donít take them out, just loosen for later.

Now its time to remove the timing belt. The right side cams are unloaded, but the left side cams are loaded. I removed the lower idler and unlaced the belt. I did notice the left side intake rotated on me counter clockwise. The left side exhaust cam was loaded but did not move. If I were to do it again, I would have had somebody with two 17 mm wrenched hold onto the left intake and exhaust cams and would have eased them to the unloaded position. But no damage was done. Now you can remove all four cams sheaves. Once you remove timing belt, remove the inner timing belt covers. To get the left (drivers side out, you have to pull out the oil dip stick. It is held in the oil pan by two o-rings. It will pull right out. Then your will be able to remove the left side inner timing belt cover.

Hereís what I did. I made a table up and used 8 Ĺ X 11Ē paper and marked them accordingly. Left side intake, left side exhaust, right side intake, right side exhaust. I also had several boxes marked with parts I took off.

Next you can take the valve covers off. On top of both valve covers are breather hoses, remove and put in appropriate boxes. On the right side, on top of the valve cover is a bracket that the sparkplug wires set in to. Remove this.

Now remove the valve covers. Almost all of them were easy to remove except the bottom rear one on the drivers side. I was tight but was accessible.

Now comes the fun part and the beer should be put on ice for now. It is important to keep the parts (the cams and lifters) in order and in alignment. This is where the table and paper come in. You can remove these in any order that you want but keep them in order. As you will notice, the intake lifters set in an upright angle and it is unlikely that these will fall out. But a friend underneath the car will be a life saver. First loosen the cam cap and the two journal caps up but donít remove. Now have your best friend under the car holding onto the cam and remove the cam cap and the two cam journals caps and set them in on the table in order. Each journal cap will be marked as a number cylinder exhaust or intake but keep them in order anyway and you canít go wrong. As you remove the cam, have your buddy make sure the lifters donít come falling out. Take the cam to the table and set it on the paper marked accordingly. Now with a magnet wand grab the front lifter and take it to the table and however you do it, you want to put the lifter you took out back into the same hole you took it out of. You get the picture now. Keep everything in order with all four cams. Remember, when you are working with the exhaust cams, when you remove the cam, the lifters will want to come sliding out. Thatís where you buddy better have his crap together.

Now assuming all the cam parts and lifters are on the table in order, now comes the fun part. Breaking those tight ass head bolts free. These are stretch bolts so you better be ready for some muscle. When I broke the first one free, she cracked and thought I was home free, but that was just a teaser. It was still tight as hell and had to get some serious leverage to break it free the rest of the way. But after several bolts I did find out that once you here it break free, just keep on pulling and that seemed to be more effective and easier to loosen. On the left driver side head, I just left all the bolts in the head and slid it up thru the top. The passenger side right was a piece of cake but still had to leave some of the long head bolts in the head for removal.

Overall, not that hard, but time consuming.

I went and got heads milled and here is what I also replaced while I was in there. And after the heads cam back, I put in new NGK sparks plugs.

Water pump
Timing belt
All three idlers (were all noisy)
Valve cover gaskets including spark plug tube seals. (ebay for $30 delivered)
Head gasket
Cam seals
Intake gaskets
Exhaust gaskets
Spark plugs
a/c belt
alternator belt
new antifreeze
changed oil.

There are plenty of online Subaru sites that offer the improved head gaskets at around $28. Heres what I did. I called the local Subaru dealer and asked them for a price on the head gasket and he told me $38. I then asked him how much are you going to give them to me for. He asked what my name was. I told him John G. and he said he would give them to me for $31. I then asked him about cam seals. He gave them to me for a discount also. The funny part is, he had no idea who I was. Just goes to show you discounts from the dealer can be had.

The heads came back nice but the guy who did it did not clean out the shavings. I used carb cleaner and rinsed it real good.

Time to put it back together.

Make sure you clean the cylinder block, intake and exhaust. I used a green scrub pad and it shined it up like new. If you have to use a scraper for any reason, be extremely carefull not to gouge the aluminum.

Hang to new head gasket on the block and make sure you it is on the right way. The tabs should be pointing out. Just make sure the oil port hole lines up. It really can only go on one way with all the ports open.

Here is a nice little trick. I would be a real pain in the butt to put the lifters into the head with the head on the car. Clean the lifters up real good and check for smoothness. Then get some sticky grease of some kind and coat each lifter and insert into the hole you took it out of. Then a dab of grease on top around the shim just in case to keep shim on lifter. Once you have done all this, you are ready to put the head on.

Now put your head bolts in the head and adjust accordingly so you can slide the head down thru and start the bolts in. I snugged them all first then proceded with the torque sequence. What I did find out it appears during the first torquing of the head bolts, you are crushing the new head gasket. Then when you loosen them 180 degrees, then another 180 degrees, you are relaxing the gasket. Then the final torque sequence, then 90 degrees more, then 90 degrees more. For the 180 degrees loosening, I marked the socket so I knew when to stop. But for the 90 degree tightening, I marked the top of the head bolt, turned them all 90 degrees, then again 90 degrees and when I was done the mark on the bolt was at the bottom.

Ok, now for putting the cams on. When laying the cam in, you want to lay it in at an unloaded position. You will want to coat the bottom of the cam cap (this is the cap where the cam seal goes) with aneboilic sealer prior to setting the cam cap on. If you donít, you will leak oil. Now put the cam cap and the journal caps on and snug the bolts, then do your final torquing. I think these are are ~7 ft/lb and didnít have a torque wrench that goes that low so I torqued it by feel. Again, do the same for the other side.
Of course check everything you need to replace. Check the three idlers, If you are not putting a new tensioner in, when you remove the tensioner, you have to compress it and pin it. (see your manual for this procedure). I got a new tensioner so I was good to go. I replaced the water pump and thermostat when I was in there because I was so deep anyway, it would be stupid not to.

Put the inner timing belt covers back on. Put the oil dip stick back in. Put all, but the lower idler on the right side of engine, not the gear idler, back on including the tensioner and torque to specs. Now put the cam sheave back on and snug. To torque these, I used a 2 5/16Ē socket and held it with a chain wrench. I put an extension with a 17mm socket thru the socket and was able to torque to spec no problems. Your buddy will come in hand either torquing or holding sock. Of course do all four.

We needed a third hand to lace the timing belt. I held the two left cam gears with 17mm wrenches after I brought them into time. Check your manual for properly bringing them into time, but I think the intake turns clockwise and the exhaust turns counter clockwise when bringing the timing marks together so valves donít hit. Then another guy held the right side cams (remember, these were unloaded anyway. Double check your crank mark to make sure it did not move. Start lacing belt on right side aligning top and side belt marks to marks on inner timing cover and work the other way. Once you get the belt laced and the marks aligned, put the lower idler on and torque to spec. after final inspection and all the marks align. Pull the pin on the tension and if everything went as planned, you should be good to go.

Now put your new gaskets and grommets associated with the valve covers on. I didnít get new cam plugs, these are the have moon gaskets on the head. Just put some rtv on them an insert into head. Now run a small bead across the cam plug and at every corner where the valve cover sets on. This is where they always leak. Now put the valve cover on and tighten.

Now start putting back together in reverse order.

I did turn the engine over one revolution to make sure the I was still in time. Remember, the timing marks wonít line up again for ~40 revolutions, just check the cam timing marks.

Once back together, I filled it with coolant. I know some people have trouble with air locks, but I have a tool to pull vacuum on coolant system to check for leaks, and it held good. Then I just stuck the tube into a bucket of antifreeze and it sucks it in. No air lock. Then time to try it. I just bumped the key to make sure nothing was hitting and it wasnít. started up and bingo. I am done. I let it warm up then changed the oil.

Now it is time for a Molson Ice.

The end
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