xyzb Posted June 11, 2015 Share Posted June 11, 2015 In the process of pulling parts to do head gaskets. Rotated the crank to get everything in alignment for a visual before pulling the belt. Pulled the belt and the right side cams were under load and rotated when the belt was pulled. Should I be concerned about the valves or is it not an issue? Thanks! Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 11, 2015 Share Posted June 11, 2015 No issue. The cams rotate back because the valve springs push back on the cam lobe, when the lobe rotates out of the way it allows the valves to close. Just use a wrench to turn them back the direction needed to line up the timing marks when you're ready to put the belt on. The DOHCs can be tricky to keep the sprockets from turning. I get the belt on the lower sprocket then pull up on the slack part of the belt to keep tension on the belt against the sprocket while rotating the upper to the timing mark. Quote Link to comment Share on other sites More sharing options...
1197sts Posted June 11, 2015 Share Posted June 11, 2015 Just to be clear, there are some situations where valve damage can happen if the cams are turned the wrong direction when the timing belt is off. When the crank is properly positioned take caution when turning the left cams, the manual warns to turn in specific directions only for each cam. DOHC caution turning cams.pdf Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted June 11, 2015 Share Posted June 11, 2015 on the ej25D dohc, when the crank is in the correct position, 3 of the 4 cams are at rest. one, the left intake i think, is under load. when it turns, it is snapping all the valves closed, away from damage. so not to worry. but what if you were not using the correct timing marks? well then is MAY be possible for damage, i do not know. i would have to study it for a bit. so make sure you are using the correct timing alignment marks. reposition the cam to the correct place when you put the belt back on. when positioned correctly, the cam should hold its position. if it will not hold, it is not in the correct position. of course, it may get bumped out of position when you are working with it , but such is life. a long time ago i heard that there was no possibility of valve to piston damage on this engine. but valve to valve damage was common. i do not know if this is true. just make sure the crank is in the correct position. Quote Link to comment Share on other sites More sharing options...
darsdoug Posted June 12, 2015 Share Posted June 12, 2015 Careful because those valve stems are about half the diameter of a pencil and they will bend easily. There is a special tool you can get that will lock both upper and lower cam pulleys in place during a timing belt installation. You could make your own by tack welding a couple old sockets onto a piece of metal X 2. Works great. Quote Link to comment Share on other sites More sharing options...
xyzb Posted June 12, 2015 Author Share Posted June 12, 2015 Is there an easy way to check for bent valves without removing the springs, etc? I'm assuming that if they are bent they are going to hang when I rotate the cam. Thanks for the article links and PDFs. I knew about the valve issue, I wasn't expecting the one cam to rotate like that. Live and learn - my first interference timing-belt, head repair. Thanks Quote Link to comment Share on other sites More sharing options...
1197sts Posted June 12, 2015 Share Posted June 12, 2015 With the head installed you could do a compression check, with the head removed you can do a simple leak check by turning the head over, make sure Cams are unloaded and spray a light oil or brake clean into the recessed area of the head where the valves are and it should hold for a few minutes. Make sure to be careful when turning the cams as valve to valve damage is possible with a twin cam head. From what you are describing I doubt you have bent valves, if all it did was spring back when you took the belt off, that is very common. I have found it hard to verify if valves are bent or not just by looking, it doesn't take much for them to leak. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 13, 2015 Share Posted June 13, 2015 Best way is to do a leakdown test. You could also check valve lash clearance. A bent valve will hang open slightly and clearance will be wider, but it may not be excessive so clearance isn't a guaranteed way to check. The at home quick way is to slap a timing belt on it and fire it up and see if it runs smooth. Did it jump time? Belt break? Quote Link to comment Share on other sites More sharing options...
xyzb Posted June 13, 2015 Author Share Posted June 13, 2015 (edited) It didn't jump time. I'm just doing head gaskets. Check this out. When I was taking the radiator out I noticed some fine white particulate - like scale in the coolant. When I removed the head it was really ugly. Huge white chunks all around in the cooling jackets. Is this thing worth throwing money at? I'm concerned it really heated up bad. I'm sure the radiator and most likely the heater core have some smaller debris as well. Thanks Edited June 13, 2015 by xyzb Quote Link to comment Share on other sites More sharing options...
ccrinc Posted June 13, 2015 Share Posted June 13, 2015 That's not normal. It looks like somebody put some kind of coolant "additive" in it at some time. I've torn down and cleaned up many engines and I've never seen chunks like that before. Definitely need to flush that junk out! Emily Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 13, 2015 Share Posted June 13, 2015 Subaru recommends adding a "conditioner" to the coolant, which is basically a stop leak type product. Those engines had trouble with the head gaskets weeping externally, so the solution (rather than better gaskets) was to add crud to the coolant. Looks like someone went overboard on that one. Scrape out the big stuff. When you get it put back together you can try running a flush solvent in it. The stuff in the block won't hurt anything, but if there's a ton of it in the radiator that will cause problems. But the radiator is easy to replace. My worry with that much stop leak crud in the system would be that it has partially clogged the heater core. The heater core bypass route of the cooling system is vital for proper cooling system function on these engines. Quote Link to comment Share on other sites More sharing options...
xyzb Posted June 13, 2015 Author Share Posted June 13, 2015 Any suggestions on what to put in the heater core to dissolve the junk and flush it out. I may shelve the motor and get another used one. I just hate to spend time on the heads, seals, timing belt kit on a questionable motor. Comments? Anyone have a motor they would like to sell? Thanks! Quote Link to comment Share on other sites More sharing options...
86 Wonder Wedge Posted June 13, 2015 Share Posted June 13, 2015 It does look like someone added some sort of "stop leak". From personal experience, I'd have the radiator professionally flushed and take a hose and back-flush the heater core and flush out every coolant passage on that block. I don't see lots of "tiny" particles floating around, so it might have just clumped together, your heater core might be safe. I find it's really difficult to ACTUALLY clog up block passages on the EJ motors as they were pretty big and the aluminum surface in the cooling system is a very "smooth" surface so nothing much really "sticks" to it. Quote Link to comment Share on other sites More sharing options...
xyzb Posted June 13, 2015 Author Share Posted June 13, 2015 Actually, the bottom radiator hose/outlet had settled particles in them. I have been looking at threads that say to use citric acid (granular packets)mixed with hot water and dump it into the heater core hose and let it set for 15 or 20 minutes then flush it. Repeat as need until the water runs clear. Not sure how bad it would be to pull the little beasty. I have replaced heater cores on other vehicles and it its usually not fun. Thanks Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 13, 2015 Share Posted June 13, 2015 Dashboard has to come out to get the heater box out. Back flush is an easy option. Peak makes a flush solvent that works pretty well. They recommend that you run the engine for 3-6 hours of normal driving to get the best results, then flush the system thoroughly with water. The citric acid approach sounds like a good idea as long as it doesn't corrode the aluminum. Quote Link to comment Share on other sites More sharing options...
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