nebmaster Posted July 2, 2005 Share Posted July 2, 2005 So, in my neverending quest to keep my subie on the road, I've run into yet another hurdle. After a trip to Houston today, I noticed my car has started to make a new, unusual knocking noise. It sounds to me like it is coming from the front of the engine, but I can't be too sure. When I rev the engine, the sound either goes away, or is covered up by the other engine noises. I really, really hope that this problem is not as expensive as it sounds, I'm completely lost, so help would be really really appriciated. The sound it is making can be downloaded here (About 1MB .WAV file) I recently changed the oil, but I don't think that has anything to do with this (I've checked the oil level and it 's fine...) Don't know how long it's been since the timing belt has been changed...the last major work was installing keyless entry. (and the last major relavent work has been changing the front axles, tie rod ends and balljoints.) That's all I can think of for now, if anyone needs any additional info to help me find the problem, just ask. Thanks in advance P.S. It's a 1996 Legacy L with a 2.2L, 180,000 miles (yeah, that probably should have been the first thing I said...) Quote Link to comment Share on other sites More sharing options...
Andyjo Posted July 2, 2005 Share Posted July 2, 2005 Sounds like your lifters maybe.. but that'll usually just got louder, and faster when you rev the thing. It sounds like mine does... and i just ignore it Quote Link to comment Share on other sites More sharing options...
ShawnW Posted July 2, 2005 Share Posted July 2, 2005 Dont ignore it. It sounds like a lack of oil pressure among other things. Keep in mind the oil light only comes on at between 3 and 7 PSI. At 3000 RPM with a load thats REDICULOUSLY hard on the motor. Might as well run dry really. Also check: Check thrust on the crankshaft for play. See if the crank pulley wobbles and if it doesnt make sure the bolt is tight. If it does you probably have a classic case of crank pulley key breaking and the need for a kit from s-wings. It also sounds like the crank thrust may be gone from a main bearing going south. If so its time for a rebuild. That audio file is helpful but not limiting it to alot. HElps to know its a rotational noise but you really need to get your longest screwdriver out and do the old engine stethoscope test. Quote Link to comment Share on other sites More sharing options...
Setright Posted July 4, 2005 Share Posted July 4, 2005 Well, the sound has the characteristics of a main bearing worn thin. Low pitched thud. However, it doesn't seem to keep a rythym. It sounds like it skips beats every now and then. Failed bearings should stick to one frequency. Therefore, it could be a failed timing belt tensioner. Lack of pressure in the tensioner will cause it to knock. Not to mention the possibility of the belt flapping about and making more odd noise. It's possible that higher revs tension the belt up a bit and make the sound go away. Get the timing belt covers off - that means crank pulley must come off - and have a look at the belt and tensioner. On the tensioner you are looking for oil leaks. The belt itself would have an uneven wear pattern, and probably have scuffed the inside of the timing belt covers. Good luck! (Nice recording by the way.) Quote Link to comment Share on other sites More sharing options...
ferret Posted July 4, 2005 Share Posted July 4, 2005 Before I would rip anything else open, I would remove the drive's side timing belt cover. Then start the engine, look and listen. Some timing belt tensioners, both the older type on the 2.2, and the newer type on later 2.2's and 2.5's are known to become sloppy and make a noise like yours. In colder climates, this happens when first started and is sometimes confused with piston slap. But I have seen one that was bad all the time. Take the time and pull off the cover. Start the engine, watch the belt for slack and slop. I use and old piece of heater hose for years now as my 'stethescope'. Holding one end to my ear, it helps me locate engine noises. I also had a Water Pump (90 legacy LS wagon), back in 1992 when the 2.2 was only a baby, make a percolator type sound. Found that after it seized and took out the timing belt. (overheated and destroyed itself). That made that sound for less than a week. Good luck....hope it's not your mains. Quote Link to comment Share on other sites More sharing options...
nebmaster Posted July 5, 2005 Author Share Posted July 5, 2005 Okay, I removed the driver's side timing belt cover and checked to see if the belt did anything odd while the car was making the noise. Although the belt is starting to show its age (I'll have to replace it soon...) it appeared to be running smoothly. I poked around the engine compartment some more, using a broomstick (because my longest screwdriver isn't that long... ) and the noise actually seems to be coming from the transmission. More evidence comes from the fact that the noise intensifies and changes pitch when I put my foot on the brake and put the transmission into drive...all the while engine RPMs are staying the same. So...I think it may have something to do with the transmission, which I had replaced by one of the most incompetent shops I have ever encountered last summer. It's still under warranty, so I'm going to drive the car about fifty miles to the next closest location of this terrible chain (They put transmission fluid in my front differential, and then tried to tell me that it was the correct fluid. I had to call the dealer and get them to point out to the shops owner that this was completely wrong before they would do anything about it...), and hope their mechanics are more competent than the ones where I had the transmission replaced initially. If anyone has any further insight as to what they could have done wrong (and why it has taken almost a year for symptoms to show up...) I'd appreciate input. Thank God my mom insisted I get the extended warranty...I never thought that extra $90 would ever pay off... Quote Link to comment Share on other sites More sharing options...
ccrinc Posted July 6, 2005 Share Posted July 6, 2005 Crack flex plate Emily http://www.ccrengines.com Quote Link to comment Share on other sites More sharing options...
rsthj Posted July 6, 2005 Share Posted July 6, 2005 Crack flex plate Emily http://www.ccrengines.com Is a cracked flex plate a reasonably common failure? I'm chasing a similar noise. Thanks, Tom Quote Link to comment Share on other sites More sharing options...
nebmaster Posted July 8, 2005 Author Share Posted July 8, 2005 Yup, a cracked flex plate it is...and the transmission shop is currently refusing to repair it because it wasn't replaced with the new transmission. I've called two seperate Subaru dealers and spoken with my usual mechanic, all of which say it is uncommon to replace a flywheel/flex plate, and when they do have to it is usually related to a problem with the startor. I guess we will see what happens...If anyone else has had similar experiences, please share. Quote Link to comment Share on other sites More sharing options...
ccrinc Posted July 9, 2005 Share Posted July 9, 2005 Quite common actually. I believe I remember Rick saying once that the problem is frequently due to someone replacing the torque converter who doesn't know what they're doing. Torque converters are tricky to reinstall, on 4EATs anyway. The placement must be precise and they will only "really" fit one way. I think the issue is that they seem to be on correctly and really aren't. The other part that breaks if the converter is not installed correctly is the sealer pipe for the pump drive. Emily http://www.ccrengines.com Quote Link to comment Share on other sites More sharing options...
nebmaster Posted July 9, 2005 Author Share Posted July 9, 2005 Well, after quite a bit of rather heated discussions with the transmission shop, I was finally able to convince them to replace the flex plate under warranty. Thanks to everyone here for their help, I really do appreciate it. Quote Link to comment Share on other sites More sharing options...
Setright Posted July 10, 2005 Share Posted July 10, 2005 Good thing :-) Well done on your negotiation skills! Quote Link to comment Share on other sites More sharing options...
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