Endless mount problems

So I took my car in to replace the timing belt a few months ago as I neared 100,000 miles on my little 05 Neon and they discovered a broken motor mount. Replaced it, then about a month later another one broke. Replaced that one. My car was still vibrating and making a lot of noise like it was about to fall apart any second so I took it in to get all four motor mounts fixed. Vibration persists! They said it was the transmission mount, so I replaced that too and the noise improved a little but now they’re saying a whole other mount is broken. I planned on keeping my car until the tires fell off but it sounds like that could be anytime now. Please help me, what could be the problem?



Thank you!



-Jenny

Cause And Effect. The Effect - Broken Motor / Transmission Mounts Are Being Fixed, But Not The Cause Of The Vibration Which Breaks The Mounts.

Jenny, If your engine can survive more vibration you’ll need more mounts unless the cause of the problem is found.

I’d take a serious look at the harmonic balancer and run a compression check on the engine just for a start. Have you had a recent tune-up ?

CSA

Did the vibration begin at the time they changed the timing belt?

Some 4-cyl engines have a balance shaft that is driven by the timing belt. If that balance shaft is off a tooth or two when the belt gets replaced, a vibration occurs.

Joe, Whether It Happened At That Time Or Not, You Might Be Onto Something.

It appears that these 2.0L engines have an “A” (cam) timing belt and a “B” (counter balance shaft) timing belt.

The timing of the “B” belt could have been set improperly or “skipped” or broke.

CSA

I Don’t Know If The Information I Gave Regarding Timing Belts A & B Is Correct. I Got The Information From A Repair Guide That Sounds A Little Like “Hilton” , But I Can’t Find Another Reference To It, Anywhere!

My apologies if I did give wrong information. I’m even getting conflicting information regarding a counter-balance shaft on the Neons. It seems that most have a 2.0L engine and some have a 2.4L engine. Apparently they have used both DOHC and SOHC 2.0s over the years.

At any rate, if it’s got a balance shaft run by a belt as Joe suggested then it certainly could throw in some vibration if it went out of time.

CSA

FYI - Another Neon Tid-Bit:

I don’t know if this is an automatic or a manual transmission Neon, but I’m finding out that mounts usually are only good for just about 100,000 miles in these Neons, particularly in cars having manual transmissions.

Jenny, How about more information ?

Do you have an automatic or manual transmission ?
Do you have a 2.0L engine and does it say SOHC or DOHC on it ?
Does the car generally run smoothly, at idle and while accelerating and driving ?
Did it run the same before and after the timing belt replacement ?

CSA

If this problem only occurred after the timing belt change then odds are the belt is not timed correctly.

So a mount is allegedly broken, followed by yet another allegedly broken mount, followed by replacing 4 mounts, followed by replacing a transmission mount, and now yet another mount is allegedly broken?
What, are these mounts breeding like cockroaches or something?

It seems like so many manufactures have motor mount troubles lately.