9/25/2019 Ej20 Engine Valve Adjustment
I am thinking this would also be a good time to adjust the valve clearance. (Solid lifters, DOHC.) I have heard that some people have been able to accomplish this with the engine in the car and without using the special Subaru tool 498187100 to compress the spring to get the shims out. Valve Adjustment DOHC 2.5 Liter Engine: Both right side resin camshaft sprockets have a single arrow embossed on their front surfaces. The position of these arrows determines which valves are to be measured and/or adjusted.
It is not a difficult job, but it requires patience and the ability to really embrace your vehicle in many interesting positions.Yes, the dealer had all the shims I needed in stock. Basically here is what you do:(1) Remove the valve covers (and all the stuff in the way)(2) Remove the right side timing belt cover. (if you want to use this to aid in positioning of the valves according to the Haynes book. Saves a little time, but probably not worth it, yoiu can simply observe the valves directly.(3) Turn the crank pully until some valves are at the lowest point on a cam.(4) Measure the clearance between the cam bottom and lifter shim with a flat feeler gauge.(5) Repeat steps 3 and 4 untill you have measured all 16 valves.(6) The desired clearances are.20 mm intake and.25 mm exhaust. Any gap thatdiffers by more than about.02 mm should be reshimed. Go through your listand see which ones exceed this.(7) Remove the shims on the lifters for these valves only.
I did this by using a large screwdriver to piviot against a rough part of the cam and push the lifterbucket down by its edge with a twisting motion. The spring tension is not too strong this way. While holding the bucket is down, pop out the shim by pushing a very small screwdrived in the little side gap designed for this. Push it out of the way to make it fall to the ground, or grab it with needle nose pliers.This method seems to work very well.
You need to use a stubby screwdriver for the intakes to work from under the cam. The exhausts are a little easier to remove. (If there is more interest in this I will post greater details).(8) Identify each shim by writing the valve number it came from on the back in marker.(9) Go inside and make coffee. Measure the thickness of each shim with a micrometer, and based on this, calculate the desired thickness of the new shim that would be required to bring the clearance to desired clearance (either.20mm or.25mm).(10) See if you can reuse any of the existing shims you are removing, and go buy the rest at the dealer (6.38 each).To make things easier, I suggest converting feeler gauge measurements to mm right away and working entirely in mm rather than inches. You need resolution better than 0.001 inches idealy, so measure carefully even to the point of saying the clearance is in between guage sizes, i.e., 0.0095, etc.
Remember that a single thousandth of an inch (0.001) is 2.5 shim sizes! There are 60 shims available in increments of 0.01mm.Good luckRich. Rich:Thanks for posting your experience here. You mentioned replacing 9 of your shims. How far out of spec were they?
And in what direction (less or more than spec)? Thanks.I posted about this a while back, looking for info on the valve clearance adjustment, since I have 102,xxx miles on my '97 and it's due in the near future.
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I couldn't get consistent info from three local Subie dealers regarding the procedure, or cost of it, so I kind of just gave up for the time being.Thanks for any further details you could provide.Steve. Great write up of your procedure. My 99gt wagon is approaching 90k miles and I was wondering if this was something that could be done in the driveway or not. Sounds like it could but I willthink about whether it is really necessary at 105k per manual or better to wait till 150k or higher. The only time the engine has made a lot of noise was knocking around 60k and changing spark plugs fixed that. I would like to hear from more people that have done this or had it done by dealer or independent mechanic.
From what I have heard, the potential danger in not adjusting valve clearance is not that the clearance will increase, but that it will decrease. An increase leads to noisy valves (tapping), but it won't kill you engine. A decrease, however, can be fatal. From what I understand from reading, as valve seats wear over time, the valve rises higher and higher in the head when it closes, and this means there is less and less clearance between the lifter shim and the cam lobe. This can begin to reduce the amount of time the valve spends closed in direct contact with the head. The problem is that this is the valves method of staying cool. It must conduct heat into the seat when closed.
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If your clearance ever gets to zero, the valve will not touch the head firmly at all and it will burn up. I hear this is particularly an issue for exhaust valves. I guess this is why they get.25 mm setting while intakes get.20. I would be happy to hear from anyone more experienced with this.
By the way, my 98 outback is running fine now with its new shims, timing belt, tensioner, and water pump. But it is still a noisy engine. Maybe I'll pull it out next year and rebuild completely (get those.&(.&.&^ slapping pistons out!)Rich. I so here you. I pulled by 2.5DOHC and replaced it with a 2.2 EJ from a 99. Never had done much Subaru work before,so on a long holiday weekend to get it back on the road for Monday. I swapped my 2.5 heads on the 2.2 block.
I just could not stand the piston slapp any longer(it was like my ex-wife- got noiser with age without any net benefit.)If i had wanted a diesel I would have bought one.Anyhow, I have a little noise on start up (maybe loose valve clearence?) a little rough idle at times but all in all I don't miss the 2.5 block.Note: if I had an adapter plate to bolt the 2.5 intake on the 99 -2.2 heads I would have used them. They are a beautiful design, and easy to adjust. Easy I like.I will try the adjustment,without the tool.I too have found these forums priceless.thanks to all who post.Andrew.
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