timfreddo Posted September 30, 2009 Share Posted September 30, 2009 hey guys. 1994 legacy t-sr. 2L quadcam. So iv'e given up on trying to put the beast back together again, will let a mechanic do it for me. reasons for doing this are that whilst trying to re-tension bolts holding the cam pulleys on, i managed to spin the left in pulley, which resulted in a rather loud thunk, or metallic cracking sound. I'm guessing this was the sound of valves going where valves were never meant to go?? so instead of putting it back together (again) and seeing that it wont start, im going to get it towed to mech anyone know how long the labour should be to... 1. have a look at the valves to see if their f*&ked 2. fix valves and put the kit back together again? i dunno how it workes if iv'e already got the timing belt off? i was going to put all the screws in very clearly labelled ziplock bags for when they go to put it back together again. pain in the bum as it has a pretty new timing belt/waterpump (3000km ago, and brand new seals (i saw to that). is it acceptable for them to charge me for a new timing belt and seals? do they have to wreck the seals to get them out to look at valves? anything else i should be wary of/ have done? comments and answers are greatly appreciated anyone else have a similar tale? Cheers Tim. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted September 30, 2009 Share Posted September 30, 2009 They'll have to remove the camshafts to get the valves out, so yes the seals will be destroyed in the process. The "thunk" you heard was probably the valves CLOSING, and hitting the seat. Springs compress when the valves are open, and they do put a fair amount of load on the cams. It's more than enough to kick the camshaft back an slam them shut if it gets turned. Put her back together, she'll run. Quote Link to comment Share on other sites More sharing options...
logic23 Posted September 30, 2009 Share Posted September 30, 2009 you could do a leak down test to see if the valves are bent... its pretty easy Quote Link to comment Share on other sites More sharing options...
bgambino Posted October 1, 2009 Share Posted October 1, 2009 you could do a leak down test to see if the valves are bent... its pretty easy can you explain the process...i would love to learn... Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted October 1, 2009 Share Posted October 1, 2009 You need a leak down Test kit, and a source of compressed air capable of over 100 psi. It's basically like a compression tester, except YOU provide the compression via the compressed air, and you have a gauge that measures how fast the air leaks out, expressed as a percentage. You remove all the spark plugs, and set the first cylinder at TDC. (the kit comes with detailed instructions) Jam the crankshaft so it doesn't spin, attach the gauge, and fill the cylinder with air until the gauge reads 100 psi. There is a "normal" amount of leakage, but anything above that will be apparent and the gauge will reflect that. If the leakage is more than what's considered normal you determine where the leak is by listening. In the crankcase, it's bad rings, or cracked piston or block. In the air intake it's a damaged intake valve, same goes for the exhaust. Open the radiator cap and if the coolant starts pushing out then it's a head gasket leak. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 1, 2009 Share Posted October 1, 2009 I'm pretty sure most DOHC engines are interference, but make sure first before assuming there's damage. Also - if just the cam snapped, it might not actually be any damage. A leak down test will determine if there's any damage without any engine disassembly. The leak down kits should come with directions or just look it up online. Quote Link to comment Share on other sites More sharing options...
timfreddo Posted October 1, 2009 Author Share Posted October 1, 2009 still have the problem of not having anything to hold the pulleywheels still while i do them up, so dropped it in this morning. hopefully they put it back together, and started it up... will let you know the result and how much more it costs down here in New Zealand! Cheers for replies Tim Quote Link to comment Share on other sites More sharing options...
s'ko Posted October 1, 2009 Share Posted October 1, 2009 still have the problem of not having anything to hold the pulleywheels still while i do them up, so dropped it in this morning.hopefully they put it back together, and started it up... will let you know the result and how much more it costs down here in New Zealand! Cheers for replies Tim I agree with Gary on this one. If the engine was not running and you were moving things by hand. Highly doubt that you damaged anything. I would not worry too much about the cams moving around when you are tightening up the bolt. You just have to be careful to keep them still when you are setting the timing belt One solution I have found to hold them still is to take an old timing belt and wrap it 2/3s of the way around the pulley. Then fold the timing belt over itself, and wrap it around the pulley. best way to describe it is as if you were going to wind the t-belt around the pulley. wind it clock-wise to remove the bolt and counter clockwise if you are going to tighten. You will know if you have wrapped it the wrong way b/c it will not give you resistance. BW Quote Link to comment Share on other sites More sharing options...
89Ru Posted October 3, 2009 Share Posted October 3, 2009 (edited) Cam snap makes a unnerving popping sound, if the piston was in the timing belt change position you probably don't have a problem. if the '94 dohc is similar to the '97, left side intake (top) natural spin tendency is counterclockwise, exhaust (lower) spins clockwise. If they snap, you can spin them back the opposite way without problem to mount the belt. If the cams are forced past their free rest position it may be possible for valves to contact one another. Edited October 3, 2009 by 89Ru make post more international Quote Link to comment Share on other sites More sharing options...
logic23 Posted October 3, 2009 Share Posted October 3, 2009 I forgot to add if you had the timing marks up when it "snapped" then there is NO way to bend valves. Subaru's timing marks aren't at "top dead center" they are 90 degrees off (all pistons 1/2 way down). No worries. You can also get a compression gauge that has a removable gauge. What is left when you take off the gauge is an end that will connect to most air compressor hoses. You will have to take out the valve out of the hose before you screw it into the sparkplug hole. You can take the valve out with a tire valve tool. You can loosen the rocker arm bolts so that the valves will come closed. This way you don't have to hold the cams. I could post pictures if anyones interested. Quote Link to comment Share on other sites More sharing options...
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