RumbleRumble Posted May 14, 2016 Share Posted May 14, 2016 Little background on my car 2001 Legacy GT Limited 5-Speed 103,XXX 2nd owner I bought the car in 2014 with 87,455 on the clock. It had a seeping head gasket and pretty much nothing was ever done to the car but oil changes and small stuff. This is also my first car that I did a lot of work myself. My first subaru (02 outback) made me an enthusiast. This was the first car I learned to drive stick on. The first 500 miles were the hardest probably cause the tires were shot. So I put 4 new cooper zeons on and brand new Borla Type- S muffler on it . Jeez that rumble. my god I fell in love with the car more than I already did. 200 Miles later the knock sensor goes. I ordered one and put it on myself. Fixed it. First time doing something other than filters,oil,battery and wipers. (90,003k) had the headgaskets along with a ton of other things done by Prime Motoring here in NJ. Fast forward 8 months later I started getting this knocking witch for a long time i figured was piston slap. This was a on and off problem, meaning it would go away and come back, up until now. It's back again Here's a recent video https://www.youtube.com/watch?v=7QjSfTPRf8M Link to Knocking Thread Started 10/7/15 - http://legacygt.com/forums/showthread.php/rod-knock-pistion-slapi-something-elsei-246022.html My options are New long block from Enginesus.com or Subaru Used short block Rebuild the one I have. Link to comment Share on other sites More sharing options...
birkhoff Posted May 14, 2016 Share Posted May 14, 2016 I'll take a stab at it. Maybe it's just me, but that doesn't sound like a problem deep in the block. More like an accessory failing, or maybe a cracked or burnt valve in the LHS head (since you said Cyl 2 -- I don't get that from the video). Get your stethoscope out again and, with a helper, go from one end to the other. Start at the exhaust if you need to (aftermarket, who knows...) Subaru(s) make a lot of weird sounds. Sounds that are hard to isolate and hard to find posted on You Tube. Sometimes you get lucky and hit the part that is making that sound; it will be really obvious. Exhaust, manifolds, all around the heads, timing cover, top of block etc etc. If you find a 'maybe' then you haven't found the source. The good news is that unlike most of us, you can flick the idle from the engine bay! The rest of us are all fly by wire and need a helper for this sort of thing. Link to comment Share on other sites More sharing options...
RumbleRumble Posted May 14, 2016 Author Share Posted May 14, 2016 The knock goes away if I pull the plug wires off 2 and 4 Link to comment Share on other sites More sharing options...
birkhoff Posted May 15, 2016 Share Posted May 15, 2016 Just to be clear, you mean #2 AND #4 both? Not #2 or #4, one or the other? It is potentially more interesting if you have to disable two cylinders to get it to go away. But it is equally interesting if pulling one or the other will result in the same problem. It's just that it could send us on different diagnostic paths, depending . . . Link to comment Share on other sites More sharing options...
RumbleRumble Posted May 15, 2016 Author Share Posted May 15, 2016 If i pull either 2 or 4, not at the same time. Link to comment Share on other sites More sharing options...
RumbleRumble Posted May 17, 2016 Author Share Posted May 17, 2016 Put my scope to the driver side head and I hear the knock from there Link to comment Share on other sites More sharing options...
Max Capacity Posted May 17, 2016 Share Posted May 17, 2016 When you pull the plug wire and the noise stops....that's a rod bearing in most cases, or there's something wrong in that cylinder. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
RumbleRumble Posted May 17, 2016 Author Share Posted May 17, 2016 Also there is ZERO knocking when in 5th gear through out the RPMs Link to comment Share on other sites More sharing options...
birkhoff Posted May 20, 2016 Share Posted May 20, 2016 Trying to come up with something here . . . What can be wrong with two adjacent cylinders, but goes away when one or the other is disabled?? Burnt valve -- you'd need at least two, one in each. Rod problem -- ditto HG leak between the two cylinders ? Also, with all the above I would expect the sound should change when one cylinder is disabled, but not go away. What about something in the exhaust stream? I'm not familiar with the exhaust routing for your model. Is there a cat under the left bank? Can you get under the shielding and get your 'scope on the LH exhaust manifold and related piping? I had a cracked cat that rattled in the exhaust stream at low rpm. Sounded like something in the head or block. OTOH, the rattle went away as soon as rpm was raised, and that doesn't seem to be the case for you. Link to comment Share on other sites More sharing options...
RumbleRumble Posted May 20, 2016 Author Share Posted May 20, 2016 It's engine related 100% sure. Like I said in my last post there is no noise in 5th gear while on the highway even if I keep it at 2.5krpm Link to comment Share on other sites More sharing options...
RumbleRumble Posted May 24, 2016 Author Share Posted May 24, 2016 Updated the Original thread Link to comment Share on other sites More sharing options...
RumbleRumble Posted June 3, 2016 Author Share Posted June 3, 2016 Torn the front end apart and the tensioner is fine. About to compression test in a couple of days. Link to comment Share on other sites More sharing options...
RumbleRumble Posted September 6, 2016 Author Share Posted September 6, 2016 I replaced the clutch, flywheel and fixed my exhaust leaks at the headers and the resonator, no luck. Link to comment Share on other sites More sharing options...
RumbleRumble Posted October 13, 2016 Author Share Posted October 13, 2016 It's spark knock. 89 fuel and a bottle of octane booster stopped it significantly. It's probably carbon build up. Gonna run a ton of seafoam through the vacuum and FIC in the tank. Link to comment Share on other sites More sharing options...
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