leojharris Posted March 17, 2008 Share Posted March 17, 2008 Hey .. So just today I noticed a rather definite knocking/clacking noise coming from under the hood. Leaning over the engine compartment seems to indicate the sound is coming from under both the right and left valve covers, sort of an offset right left stereo clacking if you will. But I'm not sure... Anyway ... I hate it and don't know what it is ... Here's a link to an MP3 I just recorded in the driveway; the sound is quite discernible in it: ... MP3: The noise my truck is making! ... If anyone can comment on what that possibly is, please do so. The truck was a quart or so low on oil, which I remedied, but the knocking is still there. Thanks in advance. .joel Link to comment Share on other sites More sharing options...
mws Posted March 17, 2008 Share Posted March 17, 2008 Was it just me, or did the clacking sound not accelerate/decelerate exactly with the engine revving? It sounded like the engine revs went up 2X but the clacking speed didn't. If that was the case, I would check the cooling fan and if it is hitting the shroud or something else. Link to comment Share on other sites More sharing options...
leojharris Posted March 17, 2008 Author Share Posted March 17, 2008 Was it just me, or did the clacking sound not accelerate/decelerate exactly with the engine revving? It sounded like the engine revs went up 2X but the clacking speed didn't. If that was the case, I would check the cooling fan and if it is hitting the shroud or something else. It differs ... on the slow and mild accelerations, it definitely does increase ... but on the last and much harder/faster acceleration, there is a bit of a delay before any change is heard in the clacking noise ... Very strange. Thanks for the comment ... I'll check the shroud (I did notice the other day that it is torn/coming loose at the bottom. Another thing I forgot to mention was that last week I put a new distributor in (salvage pull from a 93) but the trucks been running fine since then. Link to comment Share on other sites More sharing options...
Simon Posted March 17, 2008 Share Posted March 17, 2008 I dunno....sounds like it doubles to me. I'd be inclined to think the timing belt jumped a tooth, or 3. Link to comment Share on other sites More sharing options...
adamzan Posted March 17, 2008 Share Posted March 17, 2008 (edited) Does it do it all the time or only when its warm or cold? Do what casey says down below, mine turned out to be all 3 drive belts needing replacing. Edited March 17, 2008 by redfinder Link to comment Share on other sites More sharing options...
Casey.T Posted March 17, 2008 Share Posted March 17, 2008 Pull the fan shroud... run it Take the fan itself off.... run it(I had a clutch fan bearing go, made it wobble just the slightest) then one belt at a time.... Almost sounds like a timing cover screw hitting the Harmonic balancer.... Then again im told im deaf half the time... oh wait thats from my wife... Link to comment Share on other sites More sharing options...
leojharris Posted March 17, 2008 Author Share Posted March 17, 2008 Pull the fan shroud... run itTake the fan itself off.... run it(I had a clutch fan bearing go, made it wobble just the slightest) then one belt at a time.... Almost sounds like a timing cover screw hitting the Harmonic balancer.... Then again im told im deaf half the time... oh wait thats from my wife... Thanks for the replies ... I'll go through your suggestions this week sometime. And regarding the question of whether it happens all the time or no ... First, I just noticed it today .. and second, I would have to answer that No .. it doesn't happen all the time. After driving a few miles earlier, and upon arriving home, it had ceased. But later it started again. weird. Link to comment Share on other sites More sharing options...
95xe_sorc Posted March 18, 2008 Share Posted March 18, 2008 if its on both sides and by the valve covers it sounds like it might be your lifters Link to comment Share on other sites More sharing options...
leojharris Posted March 18, 2008 Author Share Posted March 18, 2008 if its on both sides and by the valve covers it sounds like it might be your lifters If lifter related then what is the usual scenario to repair? Is it a possibly terminal (as in engine death) problem or just noisy? Expensive to repair? Link to comment Share on other sites More sharing options...
yozsi Posted March 18, 2008 Share Posted March 18, 2008 that not lifters nor manifold leaks..... any way you can pin point where is coming from an take a picture? Link to comment Share on other sites More sharing options...
95xe_sorc Posted March 18, 2008 Share Posted March 18, 2008 he said it came from both sides from under the valve covers, thats why i thought it might be Link to comment Share on other sites More sharing options...
yozsi Posted March 18, 2008 Share Posted March 18, 2008 it also kinda sounds like the timing belt is too loose causing the belt to slap the timing cover. i have seen this happen on lots of cars. Link to comment Share on other sites More sharing options...
95xe_sorc Posted March 18, 2008 Share Posted March 18, 2008 but if it was the timing belt it wouldnt go away after driving it and the engine warming up. Link to comment Share on other sites More sharing options...
unccpathfinder Posted March 18, 2008 Share Posted March 18, 2008 but if it was the timing belt it wouldnt go away after driving it and the engine warming up. I wouldnt say that...it could be possible that the bearings in the tensioner tighten up... could it be possible that the engine mounts are loose? it also sounds to me like it could be a shaft walking and it is hitting a closeout (possibly cam shafts loosened up and are slamming back and forth in their seats? thats a pretty strange noise...do you have power steering fluid? it also sounds like it could be an airvoid in a pump or loose fan walking on its shaft or a bad bearing in the waterpump? just throwing ideas out there but I think your going to have to listen closely and possibly start pulling accessory belts off to see if the noise goes away and if so then pinpoint it from there...just dont stick your head down tehre and get it caught in something cuze that would hurt doesnt sound like lifters to me at all Link to comment Share on other sites More sharing options...
leojharris Posted March 18, 2008 Author Share Posted March 18, 2008 I wouldnt say that...it could be possible that the bearings in the tensioner tighten up... could it be possible that the engine mounts are loose? it also sounds to me like it could be a shaft walking and it is hitting a closeout (possibly cam shafts loosened up and are slamming back and forth in their seats? thats a pretty strange noise...do you have power steering fluid? it also sounds like it could be an airvoid in a pump or loose fan walking on its shaft or a bad bearing in the waterpump? just throwing ideas out there but I think your going to have to listen closely and possibly start pulling accessory belts off to see if the noise goes away and if so then pinpoint it from there...just dont stick your head down tehre and get it caught in something cuze that would hurt doesnt sound like lifters to me at all Thanks for the ideas and comments everyone. As of this morning the noise seems to have disappeared. The only thing I did yesterday was check the oil and finding it needing a quart ... added a quart. I haven't heard the noise today. But I will say that yesterday, when it was happening and when leaning over the engine ... the knocking was definitely emanating from both sides of the engine, around the valve cover area ... and it was happening in this sort of "out of phase' stereo affect. I'll keep my ear out for it again and will see if I can better isolate it with a stethescope of some kind. Thanks again ... Link to comment Share on other sites More sharing options...
Casey.T Posted March 19, 2008 Share Posted March 19, 2008 Well on my 88, i always knew it was time to change the oil when I started hearing the lifter knock... it would suck about 1/2 quart of oil over 2800 to 3000 miles... never dripped a drop... I would still check out the fan ect.... but thats just me and lessons learned the hard way... Link to comment Share on other sites More sharing options...
leojharris Posted April 21, 2008 Author Share Posted April 21, 2008 PROBLEM SOLVED! And thank god it was what it was! ... So the knocking I was hearing (see the sound file in first post) started getting louder and louder. When I ran the AC, it even got worse. I was sure my pathfinder was croaking. Sure it was a 'deathrattle' of some kind. Anyway. Long story short. It was my original Nissan drive belts which were losing 1 to 1.5 inch chunks along their length! When these gaps hit the drive pullies, I'd hear that pop/knocking noise. Yes; for the past month or so; I got seriously . ... ... Hilarious. Anyway. Thanks for the posts. Belts are changed as of today. My ride has never sounded so quiet! Link to comment Share on other sites More sharing options...
Casey.T Posted April 21, 2008 Share Posted April 21, 2008 Holy Missing Chunks.... Ya that would make some wierd noises... Link to comment Share on other sites More sharing options...
LandShark Posted April 21, 2008 Share Posted April 21, 2008 Wow holy hell man. Good thing ya caught that when ya did, as opposed to breaking one of them belts out in never never land. Link to comment Share on other sites More sharing options...
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