[Todd Rudy]

So the past few times the morning temps have been below about 25, once I get about 100 yards down the road and up to speed, I hear this deep “DUN-DUN-DUN-DUN-DUN” that seems to be coming from right underneath me (not the wheels, but middle / beneath of vehicle).

The sound goes just as fast or slow as the tires, and stops when I stop. Once I get going again, the sound will be a little softer, but still in pace with my driving.

After a bit, about a mile down the road, it gets softer and softer until about 1.5 miles it stops completely.

Any advice from folks driving in cold weather? Tags added as guesses only.

(EDIT) Some folks have suggested cold tires, which I thought might be a possibility -- *except* that if I let the FJ warm up for a couple of minutes, I don't get the effect. Others elsewhere have suggested a cold transmission (?). I can see the engine warming the transmission, or even the drive train a bit (cold lube?) but I don't think the tires would get warmed that much, certainly not as much as driving 1.5 miles would do.

 

[Dutchman]

Tires. Do you have soft rubber tires? Maybe even if they aren't, being cold has made them stiffer or harder and they are slightly out of round from sitting and roll smooth again once warmed by friction and use.

~Shot in the dark

 

[Winterpeg]

My guess is your tires have gotten "square". The rubber gets stiff in the cold.

Your tires are not likely a winter compound tire like we have up here. We don't experience this phenomenon until it's WAAY colder.

:cheers:

 

[rotorhed1]

Yep, tires. The belts and rubber take a "set" after sitting for a while. As you drive the tire flexes and builds a little heat and things soften and the tire will be nice and round again. If only one tire does this, well there may be a problem with just that one.

 

[L68SWEET]

Wait a minute, it's below 25 F in Atlanta in the morning? :surprise

That might be our high today in SE Wisconsin!

Have not noticed anything like that the few times I have driven in the cold weather.

It might be a stray cat that has climbed up underneath to stay warm. It sounds like it takes about 1.5 miles to shake it loose! >

 

[Mr Earl]

Taking a "set" overnight in cold temperatures is typical of tires with Nylon belts, you might check and see if your tires are so constructed.