Have a 2005 Montego. Car has brand new tires. Noticed that there is a pulsation that comes from the front of the vehicle when I reach about 50 mph and continues till about 65 mph. This problem occurred with the old tires as well, so I am not thinking it is a tire issue. Recently replaced the drivers side hub as it had a but of play, but the problem still persists. The passenger hub seems ok. Could it be the axle (intermediate) shaft bearing? It looks ok, not ripped apart, no noise when I spin by hand, but then again the issue is only there at higher speeds. Don't want to throw parts at this, so any ideas are appreciated!!

 

A little more info might help.
Did/do you feel it in the steering wheel when it happens?
Did the tires that were replaced have any unusual wear pattern?
Somebody has to get under the vehicle and check the drive axles for possible looseness.
Sometimes a problem in the rear can appear to be coming from the front. What is the tire condition of the rears and when were they last balanced?

 

Yes, I can feel it in the steering wheel. The tires wore evenly on front and back and there were no odd wear patterns. Tires have like 400 miles on them and were balanced upon installation a month or so ago. I did get under and check the axles, there doesn't seem to be any looseness or play in them

 

Among the things you might try,
With the wheels on the ground have someone move the steering wheel back and forth with the engine running and look for any looseness in the steering system, ie. steering rack, tie rod ends, ball joints etc.
You could also move one wheel at a time from the front to the rear and look for any noticeable difference at the critical speed.
Have someone check the engine cradle for worn or loose parts in the mounting.

 

Take a look at your wheel hubs. I had this in my 2007 Five Hundred.. had to swap out the driver side front and passenger side rear.

I first noticed it as a constant drone noise, traced it by ear to the pass rear. Once I switched it out, I noticed a pulsing noise from the front. swapped it out with a used one and it solved it.

Not a hard job to swap but it does take some time and some of the bolts are hard to reach.