2004 S-type 3.0 V6; 75k miles

After I start driving for about 1-2 minutes my RPM's start pulsating down about 3-400RPM for the next 6 minutes. After that the hesitation goes away. Any ideas? The engine light has never come on.

 

I would go to Auto Zone and have the vehicle scanned if you don't already have a scanner.

 

Torque converter possibly?

 

Maybe S307-14?

Officially titled "Surge During Warm up at 40mph to 60mph" but means fluctuating revs

Normally cured by a TCM reflash.

It'll be on here or in the FAQs

 

Vaccum leak that minimizes when warmed up?

 

Agree with jagv8, that's what I've been told, mines booked in for a reflash, service and MOT next month. Told if I put it in sport it will pulse less, appears to work.
Mechanic says that some people just put up with it because they won't pay for the reflash. At £30 I can't see the point in not getting it done.

 

What happens if you just start the car and let it idle until it warms up, is the car smooth?

Take care,

George

 

Ahhhh the aluminum intake manifold heats up enough to expand the yellow (old style) IMT O-RINGS?? I would start there, for about $6.00, I would replace with the green (new style) O-Rings:

https://www.jaguarforums.com/forum/s...ad.php?t=49214

and also if the above link finds oil on the paper towel:

https://www.jaguarforums.com/forum/s...ad.php?t=32135