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Thread: Rattle Rattle Rattle

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  1. #1
    Join Date
    Jan 2018
    Posts
    25

    Rattle Rattle Rattle

    New Beat owner, fresh import to USA. Great fun this thing is, but egad, the noise! Tightened up loose stuff all over the place, now down to...

    1) Loud rattle in 3-4k rpm range, every gear. Terribly annoying! From what i've read it's probably the clutch, nothing to do except buy earplugs, sigh.

    2) This one concerns me. After fully, fully warmed up (15 minutes or so; probably 5 minutes after up to full operating temperature) I start getting a nasty engine rattle. It's in time with the engine rpm. Higher pitch than a rod knock. Almost sounds like really harsh pre-ignition, or maybe something in the valve train. It comes on slowly, getting louder and louder the longer you drive it. It first begins in the 4500rpm range, but the range gets wider and wider the longer you drive it. It's at it worst when driving a constant speed. A slight amount of throttle makes it stop, as does just letting off the throttle. 20 minutes or so after it starts it's almost constant, doesn't get quiet with throttle trickery.

    Ideas?

    Thanks,
    Scott

    Click image for larger version. 

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  2. #2
    Join Date
    Nov 2004
    Location
    Guernsey
    Posts
    235
    I have just been dealing with a similar problem with a Subaru Vivio. In our case it was caused by a broken weld allowing the exhaust shielding to resonate at certain frequencies.

  3. #3
    Join Date
    Jan 2018
    Posts
    25
    Thanks LawrenceHarding, good thought. I had actually examined my exhaust shields last weekend looking for the source of the 3-4000rpm rattle. I've since read numerous posts about a clutch rattle that sounds exactly like what I have. That one is caused by the springs in the pressure resonating in that rpm range. My #2 rattle is different in that it initially occurs at a certain rpm but gradually increases until it rattles across the whole rev range. Also, I can't feel rattle #2, can only hear it. I can feel rattle #1, which makes sense being a resonating vibration.

  4. #4
    Join Date
    Jan 2018
    Posts
    25
    More info on rattle #2. Complete description:

    After fully, fully warmed up (15 minutes or so; probably 5 minutes after up to full operating temperature) I start getting a nasty rattle. It's in time with the engine rpm. Higher pitch than a rod knock, more of a clack. It comes on slowly, getting louder and louder the longer you drive it. It first begins in the 4500rpm range, but the range gets wider and wider the longer you drive it. It's at it worst when driving a constant speed. A slight amount of throttle makes it stop, as does just letting off the throttle. 20 minutes or so after it starts it's almost constant, doesn't get quiet with throttle trickery. Thinking it might be pre-ignition, I checked the timing (which was on the money), then retarded it a good 10 degrees to be sure it couldn't pre-ignite. No change in rattle so ruled that out (and set timing back to normal). After quite a bit of test driving I found that it only happens with the clutch engaged. Once fully warm and full-time rattle, at any speed and any gear I can push in the clutch and rev the rpms up and down and no rattle that I can detect. I'm now thinking pilot bearing or clutch release bearing for several reasons:

    -When clutch is disengaged (no noise) there's no load on the pilot to make it shake, and the throwout bearing is being squeezed, preventing it from rattling.
    -It's at it's loudest when maintaining constant speed or very slight deceleration, when the drivetrain is at is lightest load. Enough to start a rattle, but not enough to hold things in place.
    -Clutch engaged, lift off of throttle increases the load on the drivetrain, and the noise goes away. Now enough load on the pilot to keep it from rattling.
    -Clutch engaged, add throttle also increases the load on the drivetrain, noise goes away. Again, enough load on the pilot to keep it from rattling.
    -The noise is in time with engine rpm

    I'm not sure which is the more likely culprit--the clutch release bearing or the pilot bearing. Are either (or both) common noise problems with Beats?

  5. #5
    Join Date
    Feb 2014
    Posts
    161
    what's your valve clearances like?

    I'd give the head a once over, check for stuck/sticky valves. clearances. get the intake off and check to see if they're all closing fully.

    also, when you say "more of a clack" would make me think a blowing exhaust close to the head, check manifold/gaskets etc.

    what colour were the plugs when you took them out? if it's running slightly lean you could have burnt an exhaust manifold gasket out

  6. #6
    Join Date
    Jan 2018
    Posts
    25
    Thanks 79. Haven't had the valve cover off yet. Plugs are dark, rich if anything. Don't know how old they are, just got the car. The thing about valvetrain, I can't see how valve noise would occur when driving in gear, but not occur by just revving the engine to the same rpm while not it gear.

  7. #7
    Join Date
    Oct 2019
    Posts
    2
    Quote Originally Posted by BumbleBeat View Post

    1) Loud rattle in 3-4k rpm range, every gear. Terribly annoying! From what i've read it's probably the clutch, nothing to do except buy earplugs, sigh.

    2) This one concerns me. After fully, fully warmed up (15 minutes or so; probably 5 minutes after up to full operating temperature) I start getting a nasty engine rattle. It's in time with the engine rpm. Higher pitch than a rod knock. Almost sounds like really harsh pre-ignition, or maybe something in the valve train. It comes on slowly, getting louder and louder the longer you drive it. It first begins in the 4500rpm range, but the range gets wider and wider the longer you drive it. It's at it worst when driving a constant speed. A slight amount of throttle makes it stop, as does just letting off the throttle. 20 minutes or so after it starts it's almost constant, doesn't get quiet with throttle trickery.

    Ideas?

    Thanks,
    Scott

    Click image for larger version. 

Name:	Beat.jpg 
Views:	126 
Size:	132.1 KB 
ID:	2736
    I have this exact same problem and have not been able to find a solution. I have tried adjusting ignition timing and itís had no effect. I noticed in another post on this thread that youíve narrowed it down to a specific cylinder. Did you happen to locate the source of the sound for noise 2? The noise has been driving me up the wall and the fact that I nothing Iíve tried has managed to quiet it bugs the living hell out of me.

  8. #8
    Join Date
    Jan 2018
    Posts
    25
    Update: Still not fixed, but I know a little more. I was fortunate to find a Beat being parted out only a few hundred miles away, so a road trip and a few hundred bucks got me a head and a transmission. Replaced those, no change. That's a bummer, but I"m no longer concerned that something is about to explode. Just finished replacing all motor mounts. The goal for that was less shake in the car at idle, which it indeed helped. It toned down the rattle a bit too. Driver side motor mount was interesting. Looking at the top picture, the steel center of the mount rests on the chassis, the engine hangs from the threads. Comparing old vs new, the old one had the engine hanging a full cm lower than the new one.
    Click image for larger version. 

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    Next up, I ordered a noise finder https://www.steelmantools.com/chassisear.html. I'll find this if I don't go insane first.
    Last edited by BumbleBeat; 09-12-2019 at 05:15 AM.

  9. #9
    Join Date
    Jan 2018
    Posts
    25
    I FINALLY have news. The noise detector confirmed the noise coming from the engine. It wasn't very useful for narrowing down beyond that, but at least I can rule out drivetrain. Early on in diagnosing this I retarded the timing quite a bit to test for pre-ignition and the noise didn't change. I retarded it again today, apparently more than last time, because it got quieter, and still had good power, which surprised me. If a little is good, a lot is better, so I dialed the distributor as far as it would go and the noise is gone, or nearly so. There's some strangeness here. I had the timing dead on. Jumpered the connector, strobed the 20BTDC mark at 1200rpm, it's pretty routine. In the current max-retard condition, the engine light is on and the car can barely pull itself at low rpm, no surprises there. But at high rpm it drives like normal. It seems like it's advancing way too much. The other thought is that it's running way too lean at high rpm, which could also induce pre-ignition. Recall that the knock only happens under a high speed load; no noise with clutch in or sitting in the driveway revved to the moon. I'm beginning to think this mystery is an ECU problem. Make sense, since ECUs are a complete mystery to me. Any thoughts Beat Genius Steve_M? Greenscale, have you tried retarding the ignition way forward?
    Last edited by BumbleBeat; 28-12-2019 at 06:43 AM.

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