vinetu Posted January 22, 2017 Share Posted January 22, 2017 Hi, need your help... I have Subaru Legacy BL/BP4 y2008, Diesel 2L, European model. The car has ca. 200.000km, always been on service by Subaru. A month ago, a strange sound appeared from under the hood when the engine running idle. Sound is hard to explain but really bad, however it was not “squeezing”. Seemed the sound was coming from the engine belt being loose and vibrating. All this disappeared when accelerating. Subaru service changed the belt extension adjuster and the belt itself (costs of almost 400EUR!). Now after 1-2 weeks of occasional driving, the sound appeared again although not so loud as before. Not sure what causes this, I made a video with my phone (ca. 50MB) where as you can see the belt is indeed vibrating on the “right” side: https://app.box.com/s/kr028de541ym5vaowr2fuqtg22esr6i0 Is this normal? If going to Subaru service, they could just start changing different parts and me paying even more. Any idea what can be the cause? Thanks and regards, Link to comment Share on other sites More sharing options...
relative4 Posted January 22, 2017 Share Posted January 22, 2017 Wow, quite a price tag for a tensioner that costs 50 Euros. Anyway, if you're getting such horrible noise and such severe vibrations on a new tensioner and belt, one of the accessories is going bad. Start by removing the engine cover, particularly to expose the alternator. You may find the alternator pulley is wobbling. If not, use a hose as a stethoscope to listen to each pulley on the drive for excessive bearing noise. Link to comment Share on other sites More sharing options...
vinetu Posted January 22, 2017 Author Share Posted January 22, 2017 thanks relative4! I don't have the stethoscope, but "listening to the screwdriver" today I could't identify any bad bearing noise. However I removed the engine cover and here is some update: . when the cold motor is just turned on - no vibration (.mp4, 20MB): https://app.box.com/s/ccnn3n8glnj60xq24146ms4kdr3wjd67 . after a couple of minutes, both tensioner and the belt begin to vibrate as wild (.mp4, 40MB): https://app.box.com/s/0njqxv05bhuqy9pymqehqww81ib7lw2j Could that be a faulty tensioner although new? And can I still drive the car or better bring it directly to the service station? Link to comment Share on other sites More sharing options...
relative4 Posted January 22, 2017 Share Posted January 22, 2017 Oh man, that is horrible. I think you have a bad bearing in one of your accessories or idlers. Buy a 1m length of hose from your auto parts store and use it as a stethoscope. The screwdriver can only contact the alternator and compressor; the hose can get you good audio on everything. Also, remove the belt and turn everything by hand. See how it feels. Finally, start it up for a couple minutes with the belt off. See if you still get the noise. If you do, you have a deeper problem. For what it's worth, I don't think it sounds like a timing belt problem. Can you drive it? I guess. Should you? Not if you don't have to. Link to comment Share on other sites More sharing options...
vinetu Posted January 22, 2017 Author Share Posted January 22, 2017 Oh man, that is horrible. I think you have a bad bearing in one of your accessories or idlers. Buy a 1m length of hose from your auto parts store and use it as a stethoscope. The screwdriver can only contact the alternator and compressor; the hose can get you good audio on everything. Also, remove the belt and turn everything by hand. See how it feels. Finally, start it up for a couple minutes with the belt off. See if you still get the noise. If you do, you have a deeper problem. For what it's worth, I don't think it sounds like a timing belt problem. Can you drive it? I guess. Should you? Not if you don't have to. thank you for comments and advise! will try with the hose first... Link to comment Share on other sites More sharing options...
MilesA Posted January 22, 2017 Share Posted January 22, 2017 We don't get the Subaru diesel engine here in the USA, but I understand your engine has a timing chain instead of a timing belt. Your symptoms might be related to the timing chain or timing chain tensioner, that mechanical rattling sound and vibration makes me wonder. Also, noted that you say the noise goes away when the car is accelerating. Sorry, that is all I have to add to what relative4 gave you. Link to comment Share on other sites More sharing options...
relative4 Posted January 22, 2017 Share Posted January 22, 2017 Thanks MilesA re the timing chain, I obviously didn't know that. I don't know what a bad timing chain tensioner sounds like, so vinetu, please add that to your list of candidates and run the engine without the belt so you can quickly determine whether the noise is external or internal. In retrospect, I should have realized that since the timing cover is obviously metal. Link to comment Share on other sites More sharing options...
vinetu Posted January 22, 2017 Author Share Posted January 22, 2017 thank you both! honestly I have never removed or replaced the V-belt myself so a bit newbie here will try to google a bit and ask my friends to help... Link to comment Share on other sites More sharing options...
relative4 Posted January 22, 2017 Share Posted January 22, 2017 With a spring-loaded tensioner like that one, couldn't be easier. Just put a wrench on the tensioner and turn it to release the belt. Might take you 10 seconds your first time. After that, under 5 seconds. Putting it back on will take longer, but it's not hard. Link to comment Share on other sites More sharing options...
vinetu Posted January 23, 2017 Author Share Posted January 23, 2017 So my buddies in the garage checked all the clutches and listened to the barrings with the belt off - nothing suspicious. Which is good news I guess. The V-belt or the tensioner could be faulty and these would be on warantee. Meaning another visit to Subaru service station, let's see. Link to comment Share on other sites More sharing options...
vinetu Posted February 10, 2017 Author Share Posted February 10, 2017 update: Subaru service changed the V-belt, now seems fine... or at least for now. Very strange though. Link to comment Share on other sites More sharing options...
MilesA Posted February 10, 2017 Share Posted February 10, 2017 Surprising the v-belt fixed it. Learn something new every day. Thanks for the update. Link to comment Share on other sites More sharing options...
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