pcwerk Posted July 31, 2008 Share Posted July 31, 2008 Hello all, I am the proud owner of a 1996 Legacy Outback (tongue in cheek;-). Apparently, the previous owner dogged this car or something 'cause it has a terrible rattle that I thought was the lifters. The noise is causing it to throw a Knock sensor code, which makes it run like crap (chug, hesitate,etc). Finally took it down to Dealership where the Advisor God said (without hearing it) that it was most likely Piston Slap rather than the lifters. How can you tell the difference? I am desperate to try and find a fix (even got a new Subie oil filter which I will put in this weekend) since I can't afford to get a new engine ;-( Any of you folks have any ideas? Thanks in advance, Jimmy in Rochester, MN Link to comment Share on other sites More sharing options...
Olnick Posted July 31, 2008 Share Posted July 31, 2008 Welcome aboard Jimmy! More details would help. Is it automatic or manual? How many miles on it? Did you buy it from a dealership, used car lot or private party? Any service history provided? Not trying to get personal or anything--but the more you can tell about the car, the more help can be offered. Aloha! Link to comment Share on other sites More sharing options...
johnceggleston Posted July 31, 2008 Share Posted July 31, 2008 this has some god info. also, the process of pulling wires to help figure it out may help. http://remanufactured-engines.com/page4.htm Link to comment Share on other sites More sharing options...
nipper Posted July 31, 2008 Share Posted July 31, 2008 Piston slap goes away after a few minutes. Rod knock never goes away Lifter noise is a clatter and will change with RPM (btw subarus in this generation dont normally have a lot of lifter noise). A noise will not cause a knock sensor code. A bad knock sensor will cause a knock sensor code. nipper Link to comment Share on other sites More sharing options...
pcwerk Posted July 31, 2008 Author Share Posted July 31, 2008 Welcome aboard Jimmy! More details would help. Is it automatic or manual? How many miles on it? Did you buy it from a dealership, used car lot or private party? Any service history provided? Not trying to get personal or anything--but the more you can tell about the car, the more help can be offered. Aloha! Hi, It is manual with 196,000 miles on it. Got it from a lady who had bought a new Forester, and didn't need it. Service record is spotty but it does seem like she "periodically" changed the oil ;-) I'm upset at myself for not giving more detailed look at time of purchase! The check engine light was on but it didn't chug and all on the test drive? Started that about a month or so after purchase (got it in Feb. of this year). Thanks! Jimmy Link to comment Share on other sites More sharing options...
pcwerk Posted July 31, 2008 Author Share Posted July 31, 2008 Piston slap goes away after a few minutes. Rod knock never goes away Lifter noise is a clatter and will change with RPM (btw subarus in this generation dont normally have a lot of lifter noise). A noise will not cause a knock sensor code. A bad knock sensor will cause a knock sensor code. nipper Hi Nipper! It never goes away and it does change with increase/decrease RPM. I will happily change my sensor out, but my mechanic (whom isn't a Subie expert--I'm still looking ;-) claimed it would just pick-up the noise again and start the whole chugging/missing process again? Would rod knock vary with RPM? Thanks for the info! Jimmy Link to comment Share on other sites More sharing options...
nipper Posted July 31, 2008 Share Posted July 31, 2008 Hi Nipper!It never goes away and it does change with increase/decrease RPM. I will happily change my sensor out, but my mechanic (whom isn't a Subie expert--I'm still looking ;-) claimed it would just pick-up the noise again and start the whole chugging/missing process again? Would rod knock vary with RPM? Thanks for the info! Jimmy Well disconnect the sensor and see what happens. you wont hurt anything. Rod knock will be a hollow deep sound. It will vary in intensity if you remove one pllug wire at a time, when you get to the cylinder(s) with the bad rods. Soobys dont have especially noisey valve trains. Another possability is a bad timing belt idler. nipper Link to comment Share on other sites More sharing options...
pcwerk Posted July 31, 2008 Author Share Posted July 31, 2008 Well disconnect the sensor and see what happens. you wont hurt anything. Rod knock will be a hollow deep sound. It will vary in intensity if you remove one pllug wire at a time, when you get to the cylinder(s) with the bad rods. Soobys dont have especially noisey valve trains. Another possability is a bad timing belt idler. nipper Already disconnected it and drove around a few days and it didn't seem to make any difference...still hesitated and chugged as before. The other thing is I have several oil leaks (valve covers, for one). I was wondering if lack of pressure in the system due to the leaks could possibly cause the oil to not get up to where its needed? Maybe that could be causing the lifters to make such a racket? Anyway, thanks for the help. Must go to work now ;-( Jimmy Link to comment Share on other sites More sharing options...
nipper Posted July 31, 2008 Share Posted July 31, 2008 It can be that the timing belt has jumped a tooth. SInce you have all the leaking seals, it may be time to bite the bullit and : Replace timing belt Tensioner Idler Cam Seals Main Seal Waterpump Thermostat radiator Cap Soobys dont usually develop a rod knock (and as soon as a mechanic hears it he knows it) unless they were abused. Low oil level can make any engine noisey, or worse. nipper Link to comment Share on other sites More sharing options...
johnceggleston Posted July 31, 2008 Share Posted July 31, 2008 96 outback, manual.. it should have the 2.2L engine. youjust got lucky if the timing belt jumped!! did you check the oil. ? as niper said, low oil level will cause it to make a lot of noise, and eventualy hurt the engine. and since yours is leaking........... Link to comment Share on other sites More sharing options...
pcwerk Posted August 1, 2008 Author Share Posted August 1, 2008 96 outback, manual.. it should have the 2.2L engine. youjust got lucky if the timing belt jumped!! did you check the oil. ? as niper said, low oil level will cause it to make a lot of noise, and eventualy hurt the engine. and since yours is leaking........... Yes sir...it has plenty of oil. It leaks around valve cover gasket, oil sending unit, etc. but not enough to drip on the ground. It probably uses a quarter of a quart every month or so. Since there is no oil pressure gauge on the car, I was just wondering if the leaks could cause the oil pressure to be low which may make the lifters chatter? Nipper, I wish I could get all of that stuff done! Unfortunately, my DW is currently unemployed so I'm doing things on a shoestring budget ;-) Thanks again ya'll! Jimmy Link to comment Share on other sites More sharing options...
Olnick Posted August 1, 2008 Share Posted August 1, 2008 I was just wondering if the leaks could cause the oil pressure to be lowwhich may make the lifters chatter? I doubt, from your description, that the leaks would cause low oil pressure. But an oil pump with loosened screws on the backing plate and a weak o-ring could. Might be a good time to get into the front end and check the oil pump--and while you're that far in, replace the timing belt, water pump, cam and crank seals, cam shaft o-rings, inspect/change idlers and tensioner. Egads! If you can do your own work it'd be a coupla' hundred bucks well spent. If you have to pay a mechanic I suppose it would be a substantial hit. 'Course maybe a Seafoam treatment (in the crankcase) followed by an oil and filter change might be a good start. Good luck and keep us posted. Link to comment Share on other sites More sharing options...
pcwerk Posted August 1, 2008 Author Share Posted August 1, 2008 this has some god info. also, the process of pulling wires to help figure it out may help. http://remanufactured-engines.com/page4.htm Yes, this was a good article. It had me listening a little closer, and it also sounds like a metallic grinding noise in the background (low volume) kinda makes me envision metal shavings grinding away ;-( I also looked up the history of the vehicle, and if her records are complete, it hasn't had a timing belt changed in 96,000 miles! I also found a mechanic's note stating that he "found the engine has an internal lifter noise" and that the engine would have to be pulled in order to be repaired. All in all, not very good news... Jimmy Link to comment Share on other sites More sharing options...
mdjdc Posted August 1, 2008 Share Posted August 1, 2008 I had a very similar situation and it turned out to be bad rod bearings. I had to swap out the motor. I'm willing to bet, with the spotty records, that the oil hasn't been changed regularly and you are looking at rod bearings too. Link to comment Share on other sites More sharing options...
pcwerk Posted August 1, 2008 Author Share Posted August 1, 2008 I had a very similar situation and it turned out to be bad rod bearings. I had to swap out the motor. I'm willing to bet, with the spotty records, that the oil hasn't been changed regularly and you are looking at rod bearings too. Thanks for the info...I'm starting to hate this car ;-) jimmy Link to comment Share on other sites More sharing options...
hankosolder2 Posted August 2, 2008 Share Posted August 2, 2008 Rather than spending time and or $$$ tearing down the engine, why not measure the oil pressure with a gauge? If the backing plate on the oil pump is loose, it's got to make some measurable difference in the oil pressure. If oil pressure is to spec, look elsewhere for your problem. Lifter noise is not that big a deal in and of itself. The car should run more or less fine even with a badly sticking lifter or two, and it should keep running a long time. If the noise is bad enough for the knock sensor to be picking it up, it must be pretty bad indeed. You could replace the faulty knock sensor and relocate it to a different area on the engine (or trans) further away from the noisy lifters/rod/or whatever. It must be bolted to something metal for its ground. (relocating it will reduce the functionality of the knock sensor, but it will keep the engine computer happy.) Subaru also had a TSB for reducing the sensitivity of the knock sensor using a pair of resistors...it doesn't apply to this car, but it would probably work. Nathan Link to comment Share on other sites More sharing options...
pcwerk Posted August 6, 2008 Author Share Posted August 6, 2008 Rather than spending time and or $$$ tearing down the engine, why not measure the oil pressure with a gauge? If the backing plate on the oil pump is loose, it's got to make some measurable difference in the oil pressure. If oil pressure is to spec, look elsewhere for your problem. Lifter noise is not that big a deal in and of itself. The car should run more or less fine even with a badly sticking lifter or two, and it should keep running a long time. If the noise is bad enough for the knock sensor to be picking it up, it must be pretty bad indeed. You could replace the faulty knock sensor and relocate it to a different area on the engine (or trans) further away from the noisy lifters/rod/or whatever. It must be bolted to something metal for its ground. (relocating it will reduce the functionality of the knock sensor, but it will keep the engine computer happy.) Subaru also had a TSB for reducing the sensitivity of the knock sensor using a pair of resistors...it doesn't apply to this car, but it would probably work. Nathan Thanks for the info Nathan! As an update...I changed the oil (Castrol 5w-30, Subie filter) and didn't seem to help. Also, changed the front rotors and pads (had a devil of a time getting the old rusted-out ones off ;-) On our way home from the farm my wife kept smelling smoke, and it turns out the calipers were stuck and front brakes were smoking like a chimney! Drove over to this little country mechanic named Otterness in Spring Grove, whom had done some work for me in the past on an old truck I had. Well he knows a fella who owns a Subie that he had to change the knock sensor on a few weeks back and it seemed to do the trick. Asked him to check on that as well while he had my car. Today I just got the news that he fixed my stuck calipers for only $75. and he says my car is "missing". Thinks he can fix it! Maybe a wire or plug bad? I am VERY hopeful! Makes me think of what my momma would say--my smoking brakes my turn out to be a blessing in disguise ;-) Keep your fingers crossed! jimmy Link to comment Share on other sites More sharing options...
BoostedBalls Posted August 7, 2008 Share Posted August 7, 2008 If you have a miss- when it's dark outside open the hood with the engine running and see if there is a light show from the plug wires. Link to comment Share on other sites More sharing options...
zstalker Posted August 7, 2008 Share Posted August 7, 2008 Yes, this was a good article. It had me listening a little closer, and it alsosounds like a metallic grinding noise in the background (low volume) kinda makes me envision metal shavings grinding away ;-( I also looked up the history of the vehicle, and if her records are complete, it hasn't had a timing belt changed in 96,000 miles! I also found a mechanic's note stating that he "found the engine has an internal lifter noise" and that the engine would have to be pulled in order to be repaired. All in all, not very good news... Jimmy with the lack of timing services done, it's very possible (even likely) you could be hearing one of the timing belt idlers or tensioner pulley bearings failing. Try this: completely remove the two belts from the outside of the motor (pretty easy, loosen the slider part of the tensioner, then turn the verticle tensioner bolt to loosen them). Start the motor without the belts on it...is the noise still there? is it coming from the front of the motor? that's where you'll hear grinding noises from the pulleys. Even if that's not your noise, after you get the noise fixed (or during), it really would be a good idea to get the whole list of things Nipper suggested from 1st Subaru Parts or somewhere like them (almost always cheaper than the dealer), and get them replaced. My personal feeling is that with timing parts and water pumps (engine parts that are really important that they work reliably) OEM parts are going to be a good invenstment. Also thinking, if your timing belt is off one tooth somewhere, it very well could be doing what you're saying about "chugging" and hesitating when you drive it. Being just barely off timing can be incredibly frustrating, since it's so close to running well, but just not. ...I'm starting to hate this car eh, don't. these cars can be frustrating, but once the wrinkles are smoothed out, you'll get a lot of joy from it. Link to comment Share on other sites More sharing options...
Gnuman Posted August 7, 2008 Share Posted August 7, 2008 Hmmm, '96 Outback manual. That will be the EJ22, and before they went ti the interference engine and solid lifters. This car has hydraulic lash adjusters that continually adjust the valve clearance. It may be that one or more is "stuck". This also happens when the oil is not changed regularly, or cheap oil is used. Hmmm, you also have a full load of fresh oil in the pan. . . OK, Try this: start the car and let it warm up, then rev the living piss outta the engine (bring it up to 4000 to 5000RPM and hold it there for a good 10 to 20 seconds. now let it idle and see if the chatter is gone. Stop laughing! this has fixed more than one noisy valve train on cars with HLAs. . . I used to do this regularly on my car, until I changed all the seals and went to synthetic oil, which does not leave the film of "varnish" that cheap dino oil can. I do recomend that you change the seals as Nipper recomended, as well as tightening the screws on the backing plate in the oil pump. On an EJ 22, it can be done with the engine still in the car, but it is a pain. Link to comment Share on other sites More sharing options...
pcwerk Posted August 8, 2008 Author Share Posted August 8, 2008 Well the good news is that country mechanic figured it out! Turns out it was one of the wires!! I can't believe this mechanic here in town couldn't figure that out...I guess the Knock Sensor CIL through him off? Anywho, I will replace the sensor when I get around to it. At least my engine isn't totally shot ;-) I will continue to clean it out with frequent oil changes and Seafoam/Kerosene treatment. Thanks for the help guys! jimmy Link to comment Share on other sites More sharing options...
BoostedBalls Posted August 9, 2008 Share Posted August 9, 2008 great! Just don't put the engine under load with kerosine in it. (unless you want to clean your bearings out also, piece by piece) Link to comment Share on other sites More sharing options...
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