CM871 engine vibration

[Ragindirt]

Well I am going to monitor this post grizzly and see how you fair out.

[Waterloo]

Well, you can't diagnose them, it is sealed. I guess if you had some sort of testing device that could spin it and check for balance. I don't know of one, but should be able to make. I know when I replaced mine at around 700,000 miles there was a marked difference in the motor. Vibration that I had, the one I did not know I had until I replaced the damper, went away.

[Grizzly]

I had a vibration before and just had the air compressor replaced. Now it feels like riding an off balance washer. So I’m going to have them recheck it that it got timed right and see if since they’re in there already if they’ll do that too.

[Ragindirt]

If grizzly happens to replace or I still have a vibration after replacing my cam and crankshaft sensors after blowers install; I will replace mine and cut it open.

[dhirocz]

You don't 'diagnose' a damper so much, you replace it as a part of routine maintenance on the isx. It has viscous fluid in it that hardens over time, and it looses it's ability to dampen anything. They wear out naturally over 500k miles.

Also might want to look at cleaning out and testing your metering and timing actuators too. Rawze made a video on that. I had a bad one I replaced, made a huge difference. They also wear out naturally, as most things do.

I have developed a similar problem, so I'll be checking my remaining actuators and running an injector leak down test again when I get home Thursday, among other things.

And yes, check that compressor. It's supposed to go in a certain way. If they just threw it on there, that won't help with a shaking/vibration issue.

[gatow900]

Check your timing actuators. Mine had the flat metal loose inside tighten them and the vibration stopped. Open it and check if there loose you’ll need a cheep 10 mm wrench so you can grind it down to size

[ynot]

A bad vibration damper is pretty easy too diagnose, open the hood with the truck idling an watch the motor, as the vibration damper goes bad it'll start shaking the front of the motor noticably more then the rear. Mine when I changed it around 750k the front of the motor was shaking a good 2" one side too the other while trying to take back half with it.

There's also the water bottle test, set a half filled bottle of water on the top an watch too see if its move around up there or just sits still.

[Tanker93]

An older fella I met earlier in the year showed me a trick somebody showed him years ago for testing the vibration dampers. Whether it was a proper indication or not he wasn't 100% but he just showed me for the hell. Stand the damper up on a flat clean surface and mark a vertical line, leave it there for like 6 hours then come back and rotate it 90 degrees then let go of it.. Apparently if it's any good it will roll back and settle with the line in the vertical position again.

[Rawze]

(11-01-2017 )Tanker93 Wrote:  An older fella I met earlier in the year showed me a trick somebody showed him years ago for testing the vibration dampers. Whether it was a proper indication or not he wasn't 100% but he just showed me for the hell. Stand the damper up on a flat clean surface and mark a vertical line, leave it there for like 6 hours then come back and rotate it 90 degrees then let go of it.. Apparently if it's any good it will roll back and settle with the line in the vertical position again.

Interesting theory. Someone should try that with a known good one to see if it works?.