Driving a 2003 3.2 TL. Almost 250k presently. 234K when purchased. At the risk of TMI ...

Shortly after purchasing, I had the timing belt replaced. Shortly afterwards I experienced some vibration throughout the vehicle and found a bad front motor mount so had it replaced along with new plugs, power steering leak repaired, oil pan gasket replaced, etc. Tech said I should eventually have valve cover gaskets replaced as well but couldn't resolve the vibration issue. He stated this was needed because he found some oil on the plugs when changing them. Still had the vibration and the engine seemed to lag when ever I increased the load (aka accelerating) and the vibration increased. I thought maybe the tires so now have about 2500 miles on the new rear tires and the front are brand new as of 10-28-18. Same brand and size. Balanced when mounted. Still getting the vibration and now can feel it slightly in the steering wheel. At one point had a code for one oxygen sensor and had both replaced. My next step is to take it in for alignment.

To make thing more confusing, there are times, usually earlier in the day before the car has been running for a while, where it seems to run and accelerate smoothly which causes me to wonder if this might be attributable to something relying on engine temp, etc. My biggest frustration is that before I had the TB replaced this didn't seem to be a problem that I can remember. Wondering if the timing might be off now. Just looking for any "next step" suggestions anyone might have.

Thanks in advance.

 

Check to see if your idle is right, I think it should be about 680 rpm with no load, but someone else could correct me here.
If it's off, take a look at your EGR port and just in general your intake manifold. Could need a cleaning. The IACV also can get clogged up and ruin your idle, giving you some shake.
I did all the above and got my shaking to be more manageable, but it was still having issues.
Had a few misfires on Cyl1, even after my scheduled spark plug change. Turned out it was a bad coil. After I replaced that, the shaking is almost entirely gone.
At this point I've got it just about pinned down to being my engine mounts, which I've known are bad from the start. I'll be replacing my front one soon and doing the manual's recommended Front Mount troubleshooting on the way to make sure the solenoid is good.

I think if it was a timing issue you'd be having more than a shakiness, but I hardly know anything about timing yet. Hopefully someone else can chime in.

 

Thanks so much. I will give those things a shot. Really appreciate what you offered and will let you know how things turn out.

 

Sounds good, keep us posted!

 

Just an update!

Got the car on the rack and think I/we have found the problem. Ball joints, CV joints, another motor mount, etc. Time to invest a few $$$ on a car with almost a quater of a million miles. Dropping it off in a week and I'll let you know the results.

Thanks again.

 

Is it still on the original transmission?

 

I can't say for sure but if I were a betting man I would say yes.