Front suspension thunk/rattle when warm

[DWS964]

The car has developed a noise in the left front suspension. Well, in the left front corner. I originally assumed it was a loose sway bar link - that kind of noise. The odd feature is that the noise is not present when the car is cold. It only shows after being driven for many miles and something warms up. During the recent cold blast when the daytime temperatures were still around 10F, I did not hear the noise at all. Now that the temps have gone above freezing, the noise is prevalent after driving the car for a while. I sometimes wonder if the noise is more of a "binding" noise/creak than a loose thunk/rattle.
I have noticed a problem with what I assumed to be the front springs binding when turning at low speeds. (once again, this was more noticeable when warmed up). I suspected bad upper shock mounts, or that perhaps the thrust bearings were missing from the installation of the PSS9 suspension (common mistake apparently).
I put the car on the lift, and sway bar and control arm and shock bolts are tight. I might drop the shocks out this weekend to see if the upper mounts or thrust bearings are bad.

Why would the noise increase with temperature?

 

I have thought about CV joints - but the sound is not quite like the clicking/binding sound that I recall from my FWD Honda's with really high miles, torn boots, grease gone, worn out.. outer CV joints. But then, I really noticed it this AM at low speed coming into the parking lot, but both while driving straight and when turning. Perhaps more frequently when wheels are straight ahead.

I will get a thunk on as little as the 3/4" lip entering my garage. Still unsure if it is a loose rattle, or a binding noise. 
The 996 is relatively low miles - 65K, CV boots all nice, etc.
I do not recall seeing many front differential problems being mentioned here.  

 

Another hypothesis is steering rack or tie rods.  Found one reference here on RT with inner tie rods as root cause.

Suggestions?
Driving me nuts.

THANKS

[Ronnie38]

Most likely a bad rubber mount look for a rubber mount that has oil on it. That would be there first one to replace, I have replaced all of the front rubber with neoprene type, makes every thing stiffer.

[stutzchris]

I had a similar situation with MY 2001 996.  No sound when start off when cold.  Then a groan/creak when turning wheels hard right or left when warm.  Usually at slow speed in parking lot or around corners in town.  My Issue ended up being a bad upper shock mount on the drivers side.  Bushing was completely shot.  I replace both and issue was fixed.

[fpb111]

Mine does the same thing. Rattle noticeable at lower speed when hot. Because it happens only when well heat soaked, hydraulic oil or radiator outlet heating the rack/inner tie rod?, I'm thinking inner tie rods also. 

Edited February 11, 2015 by fpb111

[DWS964]

Mine does the same thing. Rattle noticeable at lower speed when hot. Because it happens only when well heat soaked, hydraulic oil or radiator outlet heating the rack/inner tie rod?, I'm thinking inner tie rods also. 

I have considered this - perhaps the power steering fluid and rack warm up?  I have been unable to detect any play in the tie rods, or any other part, by the time I get the car on the lift and get under and around it.

I had my friend drive the car and listen/feel for the noise.  Our conclusion was that is was more of a creak/binding than rattle.

Thanks everyone for the input.  Bottom line is that i just need to pull some parts out and get to the bottom of this.