Aftermarket Silverado motor mount recommendations?

donfla wrote:
The problem seems to be solved with the new mount installed. Not perfect but I'd rate 90% better, before it would dropout to the point it felt like it was going to stall but never actually did. It didn't throw any codes either.

Well, I'm glad it appears to be fixed. And thoroughly confused how a low/erratic idle could possibly be caused by the motor mount.
Seems more of a sensor/electrical/fuel system issue if those are the symptoms.

Also, I’m new to using this shop and very pleased with them.

And the mechanic did confirm the new factory mount he installed is an updated version.

Grit dog wrote:
Weird...
If you saw the motor "jump" when you did a little brake stand,it's broke. If you just saw it "flex" and no "clunk" then it's not broke.

That makes sense. I'm no expert by any means but it appeared to be flexing more than it should. The problem seems to be solved with the new mount installed. Not perfect but I'd rate 90% better, before it would dropout to the point it felt like it was going to stall but never actually did. It didn't throw any codes either. Before taking it in I did a thorough throttle body cleaning using Sea Foam and while it did blow out a good bit of smoke for a second under heavy load that didn't do anything to improve the idle.

The question is, is the engine idling rough or is there a vibration being transferred to the chassis and nothing wrong with the engine.
A bad motor mount will not "affect" how the engine runs (unless 30+ years of being a gearhead are all for naught...in which case I'm very interested in this phenomenon).

Again, if you saw the engine "jump" as in seemingly unrestrained movement, not just "twist or flex" a bit, the motor mount is shot.
Keep meaning to look at the mounts in my 2016 Silverado as I'm sure they're the same or similar, but generally a front engine, north south transmission vehicle is a fairly straight forward replacement.

Motor mounts are generally bolted hard to the frame and engine with a "bonded" rubber isolation structure between the 2 sides of the mount. Additionally, there is generally a metal "stop" built in, that if the isolation structure breaks or comes loose form either side, the engine will move, but not alot before the stop or catch keeps it from twisting excessively.
If that isolation part is broke/gone/degraded, I could see engine vibration transferring to the chassis being a perceptible condition.

On the same note, I've driven vehicles in the past with broken motor mounts fir a while without issue, as long as I accelerated slow and didnt try to twist the engine out of the car.

That is the question I would like to understand. The shop called at 9am and can tell they did a lot of reading on it finding the same service advisory mentioning shimming the mounts to solve the rough idle problem. They are trying and now agree the driver side mount is the problem.

I just need this truck back, about to order a dumpster and 14” gas walk behind concrete wet saw for a bathroom demo this weekend. We do some pretty large jobs and removing the slab inside a customer’s house getting to play in the sand below is actually kind of fun. :)

JRscooby wrote:
Can somebody explain how a bad mount will cause a drive-by-wire engine to idle rough?

It won’t.

Can somebody explain how a bad mount will cause a drive-by-wire engine to idle rough?

Amazon Prime, do them yourself.

And just to be clear, the dealer did not see the truck but the service advisor said on the phone the problem was common.

Weird...
If you saw the motor "jump" when you did a little brake stand,it's broke. If you just saw it "flex" and no "clunk" then it's not broke.