Bociba Posted July 29, 2004 Share Posted July 29, 2004 I have a metallic knock I am hoping to discover what is causing it with your help. It is right in the center of the engine - in front. It is below the alternator right about where the "main" gear is...the underpully? Starting the engine when "cold" the knock is very pronounced. It doesn't sound like a lifter/tappet knock. It does not go (mostly) away until the engine is warm. It is a metallic knock/rap that can be heard (I used a plastic tube to narrow down where the sound is coming from) underneath the alternator to some point at or near the pulley. It does not seem to be on either side (idler pulleys) nor the alternator, nor down where the water pump is. It is not a clump-clump deep knock but sounds kinda like a waterpump knock on a domestic V8 just before it goes out. There is no squeeling - like loose belts. No apparant idler bearing going out. I don't know what it is - so, here I am. I appreciate your comments and will heck out what you may suggest. The car runs fine otherwise. No trouble codes, no CE light, nothing other than this knock which like I say tends to go away as the engine warms up. Thanks. Bociba Quote Link to comment Share on other sites More sharing options...
wrxsubaru Posted July 29, 2004 Share Posted July 29, 2004 Have you checked your carnk pullie, ive heard of many of these breaking on SVXs. Once they start shacking they will hit stuff on othe engine to make noise. Quote Link to comment Share on other sites More sharing options...
Hondasucks Posted July 30, 2004 Share Posted July 30, 2004 does it do it under power but go away when you let off the throttle? could be a cracked flex plate. Also, does the noise increase in direct proportion to engine RPM, or does it seem to increase by half (if that is the case, it's in the valve train) Get a mechanics stethoscope, some of thsoe noises can be very deceiving!!! Quote Link to comment Share on other sites More sharing options...
Bociba Posted August 2, 2004 Author Share Posted August 2, 2004 does it do it under power but go away when you let off the throttle? could be a cracked flex plate. Also, does the noise increase in direct proportion to engine RPM, or does it seem to increase by half (if that is the case, it's in the valve train) Get a mechanics stethoscope, some of thsoe noises can be very deceiving!!! As I start it up the knocking sound can be heard. Increasing the rpms you can hear the knock increase - I would say proportionally - same knock just faster -perhaps not as loud. No shake or shudder to engine. It sounds like something is attched to some reciprocating device and taps something "on the way around" if that makes any sense. This past weekend I drove it fairly hard and I thought the sound went away. This morning I noticed it was still there. Belts are tight, no noticable wobble to any of the pullies. Again, the sound is somewhere between the main center pulley and the alternator. I used a piece of pvc pipe to try locating the source of sound. It is not low in the engine - it is up high. Yeah, I can't tell whether this noise is coming or going. Sometimes it is there and other times you really have to listen for it. Sometimes it is no louder than the ticking from the fuel injection. Quote Link to comment Share on other sites More sharing options...
Bociba Posted August 2, 2004 Author Share Posted August 2, 2004 Have you checked your carnk pullie, ive heard of many of these breaking on SVXs. Once they start shacking they will hit stuff on othe engine to make noise. I should be able to check today. I do not see any distinctive wobble from the pulley though - of course once it gets that bad it's really dangerous anyway. I don't want something to wobble and fly off. Quote Link to comment Share on other sites More sharing options...
Dr. RX Posted August 2, 2004 Share Posted August 2, 2004 Boy that sounds bad, maybe you should just sign the car over to me and let me worry about. (jk) Really, from what you have said, I'd say it sounds like a rod knock, can you say engine rebuild, can you say EXPENSIVE? Quote Link to comment Share on other sites More sharing options...
Hocrest Posted August 2, 2004 Share Posted August 2, 2004 You may want to mention this over at http://www.subaru-svx.net/ also. The people on this board are great, but as I've found out the SVX has problems not commonly found on other Soobs, and the people over there are a little more familiar with the oddities of the SVX. Quote Link to comment Share on other sites More sharing options...
ferret Posted August 2, 2004 Share Posted August 2, 2004 Not familiar with the SVX directly, but does it have a cam belt? The hydraulic tensioner on 90 2.2 and later 2.5's have been known to make this noise when cold. On the 2.2 and 2.5 the tensioner is just to the left front center of the engine. Very easy to hear and troubleshoot if you remove the left front timing belt cover. The fix for these is to replace them. If not a tensioner, could be the harmless, but dreaded 'piston slap'. Just a few more thoughts....and $.02 Quote Link to comment Share on other sites More sharing options...
wrxsubaru Posted August 2, 2004 Share Posted August 2, 2004 Not familiar with the SVX directly, but does it have a cam belt? The hydraulic tensioner on 90 2.2 and later 2.5's have been known to make this noise when cold. On the 2.2 and 2.5 the tensioner is just to the left front center of the engine. Very easy to hear and troubleshoot if you remove the left front timing belt cover. The fix for these is to replace them.If not a tensioner, could be the harmless, but dreaded 'piston slap'. Just a few more thoughts....and $.02 I never heard of a eg33 getting piston slap, at least not yet. How does the timing belt tensioner make that sound? I have heard of idler pullies making this sound, but not the hydralic tensioner. Quote Link to comment Share on other sites More sharing options...
ferret Posted August 3, 2004 Share Posted August 3, 2004 Check this out: http://endwrench.com/pdf/engine/EngineNoiseInfoF00.pdf Quote Link to comment Share on other sites More sharing options...
Bociba Posted August 4, 2004 Author Share Posted August 4, 2004 Boy that sounds bad, maybe you should just sign the car over to me and let me worry about. (jk) Really, from what you have said, I'd say it sounds like a rod knock, can you say engine rebuild, can you say EXPENSIVE? Well Dr. RX...just about had the pink signed over to yah and then I decided to just put a torque wrench onto the main pulley and whoa... did that think turn? Yep, now I wonder how that got loose? A few more turns, click, click. Ah, torque wrench says tight enough. Start up. Hot Dog ! No Tap! Whew.... Can we say CHEAP? Think I'll just take that pink back..fer now, ok? Quote Link to comment Share on other sites More sharing options...
Bociba Posted August 4, 2004 Author Share Posted August 4, 2004 You may want to mention this over at http://www.subaru-svx.net/ also. The people on this board are great, but as I've found out the SVX has problems not commonly found on other Soobs, and the people over there are a little more familiar with the oddities of the SVX. I appreciate your response. Found out that the main pulley was a bit loose. I don't know why and hope that I have tightened it adequately. I need to recheck that pulley because it is hard to tighten it (turning clockwise) and hold the pulley still at the same time. I tried holding the various belts against the pulley but that only works so well. Now to find a way to "lock down" that main pulley to get / verify that the main pulley nut / bolt is tight enough. Quote Link to comment Share on other sites More sharing options...
Bociba Posted August 4, 2004 Author Share Posted August 4, 2004 Not familiar with the SVX directly, but does it have a cam belt? The hydraulic tensioner on 90 2.2 and later 2.5's have been known to make this noise when cold. On the 2.2 and 2.5 the tensioner is just to the left front center of the engine. Very easy to hear and troubleshoot if you remove the left front timing belt cover. The fix for these is to replace them.If not a tensioner, could be the harmless, but dreaded 'piston slap'. Just a few more thoughts....and $.02 Actually a $0.02 solution appears to be what worked. The bolt was loose holding on the main pulley. I just need to make sure that the pulley is adequately tight now. You can't beat those "2 cent-ers"!. Quote Link to comment Share on other sites More sharing options...
Bociba Posted August 4, 2004 Author Share Posted August 4, 2004 I should be able to check today. I do not see any distinctive wobble from the pulley though - of course once it gets that bad it's really dangerous anyway. I don't want something to wobble and fly off. Crank pulley was loose! I must have turned it 1.5 to 2 x around. Don't know how that got loose. Now I have to check the tightness by somehow securing the pulley and tightening that bolt to torque specs. Holding the belts firm against the pulley only hold so well... can get some tightening. Not sure enough. I need to find out just how much torque to set the torque wrench for and then maybe it will be right. What I did tighten though ended the knock! Quote Link to comment Share on other sites More sharing options...
svxcess Posted August 6, 2004 Share Posted August 6, 2004 Bociba, I too have a 92 SVX it has the same noise, trust me I know what a trick it is to really find the "tunk, tunk, tunk " noise that does sound like it picks it up every rev. I'm really leaning on the cracked flex plate theroy. I worried whether it was crank bearing or rod but the car has run 3 years with this and nothing has broke yet. The engine seems to run great so I don't know when I'll really find it. If I do I'll let you know. Over on www.subaru-svx.net there's a bunch of info. I still think flex plate torgue converter thing tho.:-\ Quote Link to comment Share on other sites More sharing options...
slo5oh Posted August 6, 2004 Share Posted August 6, 2004 My brother had a late 80s soob that sounded like a diesel. A few mechanics told him he needed a new engine. He kept driving. 2 years late he found a new mechanic for his general stuff and the new mechanic told my brother he could fix it. The mechanic replaced his oil pump and the diesel noise went away. That engine went well over 300k before my brother sold it. Quote Link to comment Share on other sites More sharing options...
Bill90Loyale Posted August 6, 2004 Share Posted August 6, 2004 Have you checked your carnk pullie, ive heard of many of these breaking on SVXs. Once they start shacking they will hit stuff on othe engine to make noise. Nice call wrxsubaru. P.S. Pulley wrenches come in both a chain type and a belt type. I've heard it recommended that the belt type poses less risk of creating burrs. A good pulley wrench and torque wrench should set the pulley up right. Quote Link to comment Share on other sites More sharing options...
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