Hi Folks, I am new to the forum and have a 2003 S-type (unfortunately no super charger) with about 40K miles on the beauty.



Recently I noticed a strange noise/feeling at around 30mph coming into town. It was like my tire had a flat spot or something and it gave me a regular sort of a bumping along with a slight thump noise. This is a road I travel daily and it did not do it before and went away after a couple of days.



Today on the way in I noticed the RMP gauge fluctuating at around 50 mph while I was behind a truck. I did not feel a miss in the engine but definitely noticed a slight 500 RPM wavering of the gauge. Again it went away and I did not notice any performance or other issues.

Now I know the girl is getting up in age although she still has low miles. I am just curious if anyone else has experienced similar symptoms or issues and if anything more concrete was found than it just having gone away. Is there something I should check or look at. I tried to find something in the forum threads but came up empty.

Thanks,

J

 

Does it only happen when cold, but goes away when warm? Sounds like TC locking and unlocking.

 

No the engine was at normal temp. The flat spot on the tire feeling happened several times over a week on different roads and the outside temp was about 80-85. The RPM issue happened today about 10 miles from home and yes it was 38 outdoors but the engine temp was at normal.

Forgive my ignorance but what is the TC?

J

 

Torque Converter. The 6speed box has issues with them. Sometimes a reflash of the Transmission Control Unit will fix it, sometimes not.

 

Thanks if it continues I will give that a try.

j