Luvn737s Posted January 21, 2011 Share Posted January 21, 2011 I ran out of feeler gauges thin enough to measure the valve clearance on 2 of my valves. Any ideas on what size shim I could replace the current one with? If I go by the Haynes formula, I guessed I'd shave the bucket down! Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 21, 2011 Share Posted January 21, 2011 Do you know the size of the shim that's in there now? Subtract the proper amount of clearance from the size of the current shim to roughly determine which size new shim you should use. Quote Link to comment Share on other sites More sharing options...
SchwarzeEwigkt Posted January 21, 2011 Share Posted January 21, 2011 The Haynes book has a table in it with all the available shim sizes and part numbers too. The trick is to take them out, measure them, figure out which shims can be reused and which ones you need to replace. Get the ones you need from the dealer, you're good to go. I do wonder, though, if you're sticking to the temperature requirements; the book mentions it needs to be between 50 and 70 degrees out, IIRC. Are you doing this in a heated garage? If not, you'd better wait until it warms up. Quote Link to comment Share on other sites More sharing options...
Luvn737s Posted January 21, 2011 Author Share Posted January 21, 2011 No, the temps are perfect here in Phoenix. But the whole size range of shims is not that great. I would think that worst case the valve clearance would be no closer than .005 or so. I got down to .0015 and it was still too close for that. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 21, 2011 Share Posted January 21, 2011 Just to make sure, the top of the cam lobe is a full 180 off from the valve you're checking? Being just 90 off can make a big difference on some engines. There are cases of burned exhaust valves on these, theoretically because the valve lash clearance has closed to 0, then the valves start to hang open. There was a thread about it here recently. Let me see if I can find it. http://www.ultimatesubaru.org/forum/showthread.php?t=116101&highlight=Burned+valve Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 21, 2011 Share Posted January 21, 2011 (edited) Why are the valves being adjusted? If this is being done "in response" to poor running conditions (very rough, running on 3 cylinders) then the valve is already burned and "the horse has left the barn" so to speak. No amount of adjustment will bring it back. You will need to do a valve job and repair the damage. If this is maintenance and the engine is otherwise running ok - then as noted make sure the lobe is 180 degrees away from the shim. If you still can't get a .001" feeler gauge in there..... you need to change the shim. Remove it, mic. it, and subtract .010" from that measurement. Then order the appropriate shim. Either way - it's pretty safe to bet that if there is no clearance when you are checking it at room temp - the valve IS hanging open at least part of the time at operating temp. These clearance are set so they close up (partially) when warm due to thermal expansion. GD Edited January 21, 2011 by GeneralDisorder Quote Link to comment Share on other sites More sharing options...
Luvn737s Posted January 21, 2011 Author Share Posted January 21, 2011 The valves are being adjusted because of a misfire CEL code. The valve clearances are being checked per the Haynes/ FSM procedure with the engine out of the car. The tight valve is the #4 cylinder aft exhaust valve. The only other valve with very small clearance is the opposite exhaust valve on #3 cylinder, but it can at least be measured at .002". I suppose I can just go buy the smallest shim possible for the #4, because if I don't know the original clearance, I can't buy a specific size shim. I've got to pull the head anyhow for the head gasket, so maybe I'll find a surprise when I see the face of the valve, and a shim might be the least of my problems. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 22, 2011 Share Posted January 22, 2011 (edited) Misfire on #4? That could possibly indicate low compression. The #4 exhaust valve is always the one that burns on that engine in my experience. Was a compression check done prior to pulling the engine? For the future you should always perform a comp. check when these type of symptoms arise. Misfire's can be electrical or from loss of compression, etc. Pull the head. Looks like it's going to be a valve job. Don't buy any shims if you are doing a valve job - the machine shop will grind the stem on the valves to set the clearance using the shims you already have. If you were going to adjust it without pulling the head you would buy the smallest shim they make, measure, and then order the correct one. Unless you happen to have one small enough to allow a measurement with a feeler. GD Edited January 22, 2011 by GeneralDisorder Quote Link to comment Share on other sites More sharing options...
Luvn737s Posted January 22, 2011 Author Share Posted January 22, 2011 (edited) Yep, all compressions were equal (or at least reasonably so). The valve looks fine from the face. I'll get them out of the head on Monday and see from there. So far, the shims on the 2 and 4 bank of cylinders seem to be pretty close to the same size, not a whole lot of variance. This is the first time this engine has been opened up so the shims are original. The misfire symptoms have been traced through spark(plugs, wire, coil pack, knock sensor) fuel( injectors) and air (MAF sensor, compression). It seems the tight valve is the most likely culprit. The head gasket didn't look to bad, but the new one will give me peace of mind. Edited January 22, 2011 by Luvn737s Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 22, 2011 Share Posted January 22, 2011 Sounds like you caught it just in time. I think you have it under control. You should know up front that a valve job on those heads might put it over the cost of a replacement 2.2 engine (much more reliable and cheaper to maintain). It runs about $400 to $500 in machine work to rebuild those heads - typically all the guides are shot, the stem seals are shot, and half the valves and seats have to be replaced plus it is labor intensive to reset the clearances properly, etc. Just so you are aware. GD Quote Link to comment Share on other sites More sharing options...
Luvn737s Posted January 28, 2011 Author Share Posted January 28, 2011 Smallest shim available stuck in the tightest valve and it still doesn't come very close to spec (.005 vs .010). This is with just the cam installed and having not rotated the engine with the timing belt installed.Should I expect the valve clearance to open up after cycling the valve a few times? Am I looking at buying a new valve seat? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 28, 2011 Share Posted January 28, 2011 If it's that tight - probably going to be replacing valves, seats, and guides. The machine shop can open up the clearance by grinding the stem but if it's that far into the head already - chances are they won't be able to grind the valves and seats any more due to wear. Guides like to wear out on those heads also. It's typically about $450 to $500 to have a set of those heads gone through - they are troublesome from a labor standpoint and like to wear out faster than the SOHC heads. Too bad since they flow very well - just one more of the many issues with the EJ25D. Sort of a bad apple from a longevity perspective. The bottom ends aren't great either so it often happens that you don't get that second 150k from your rebuilt head expenditure..... GD Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 28, 2011 Share Posted January 28, 2011 You can grind some material off the stem if you need more room. From what I've read on here the valve seats in these rarely wear enough to warrant replacement. Generally it is the valve itself that wears the most. Quote Link to comment Share on other sites More sharing options...
Luvn737s Posted January 29, 2011 Author Share Posted January 29, 2011 Why not just replace the valve with a new one and lap it in? Quote Link to comment Share on other sites More sharing options...
Luvn737s Posted January 29, 2011 Author Share Posted January 29, 2011 It's typically about $450 to $500 to have a set of those heads gone through - GD Versus $300 for a new head? Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted January 29, 2011 Share Posted January 29, 2011 i read on another forum that rather than buy replacement shims for the valve adjustment that you could remove material from the top of the valve stems. i did not understand this or believe that it was practical, but it is what i read. is any one familiar with this process or it's viability? thanks Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 29, 2011 Share Posted January 29, 2011 (edited) Versus $300 for a new head? Where are you getting your heads? Driver's side is $324 (reman from Subaru) if you return the core. Passenger side is $464!!! I get them rebuilt for $475 for *both* heads. That's cleaned, surfaced, all new valves, seats, guides, stem seals AND the clearances already set using the existing shims. If you buy reman heads from Subaru you won't get the bucket/shim's and you will have to buy all of them and setup the clearances yourself. By the time my shop is done - they *are* reman heads. BTW - "new" heads from Subaru aren't available for the 25D.... pretty sure they sold out of them long ago. It's reman or nothing. GD Edited January 29, 2011 by GeneralDisorder Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 29, 2011 Share Posted January 29, 2011 i read on another forum that rather than buy replacement shims for the valve adjustment that you could remove material from the top of the valve stems. i did not understand this or believe that it was practical, but it is what i read. is any one familiar with this process or it's viability? That's how every machine shop does it. They always reuse my original shims - that saves me time and money as well. GD Quote Link to comment Share on other sites More sharing options...
Luvn737s Posted January 29, 2011 Author Share Posted January 29, 2011 Hooray! While the Haynes manual has a table listing the valve shim sizes and part numbers, thinner valve shims are actually available if you ask. I did and now the correct shims are headed my way to get this back together the right way! I was bumming that I might have to compromise and not get the one valve that was tightest back into spec. I hate that I have to undo some of my work, but at least it's while the motor is sitting on my bench and not back in the car. A very good day indeed. Quote Link to comment Share on other sites More sharing options...
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