2004 jaguar s-type 3.0 149,000

Greetings ! Long time lurker (8 years), first time poster. (why? maybe because i know how to use the search function?! )
anyhow...
Got a problem i cant sort out:
Cold here in Ohio. The car runs rough when first started. restricted performance. so i run the car at 1500 to 2000 rpm and count to 100. shut it off,
go inside for 5 min and gather up my stuff and let the heat dissipate through the block.
come back out fire her up and drive. runs but wont idle right. at red lights . i have to shift into neuteral and give a little gas...
BUT, once the temperature gauge goes straight up--- SHE RUNS PERFECT! and i mean good as new! BEAUTIFUL. ! Runs fabulous for the rest of the day.
I changed coil packs and plugs, Air filter cleaned MAF, checked to see intake connections are tight.
What could it be? has to be an air leak that gets sealed when warm.

changed upper plenum gaskets 8 years ago, did NOT change the lower.
Please lend me some insight... i love this car but my patience is wearing thin...HELP
And thanks for your help in advance, without this forum she'd be long gone... I do appreciate you guys...

 

oops... Codes:
P0306 Cyl 6 misfire
P0302 Cyl2 miss
P1314 Bank 2 Catalyst misfire
P304 Cyl 4 misfire
P0300 multiple misfire
P1647 heated oxygen sensor bank 2 open / shorted.
i did recently replace the upper Oxygen sensor on the drivers side....

 

In checking for air leaks, i had to replace a broken fuel pressure regulator... the pcv and Vac lines seem ok...
but the running ok once the block is warmed rules them out?

 

The P1647 needs fixing urgently and is odd as it sounds like the one you changed. If so, either a bad/inappropriate new one or wiring/connector/relay/etc.

Does it even go CL (closed loop) and within about 30 secs? Might be a bit longer if it's really cold there.

If so, what do the fuel trims at idle do as it warms up and what are they when it's nicely warmed up? If not near zero, do they drop if you rev to 2000-2500? (Classic signs of an air leak if so.)

 

also, Code P0128 !
The P0128 code in a Jaguar indicates that the engine coolant temperature is lower than the thermostat's regulating temperature. This can cause issues with fuel economy and emissions.
but i changed out the thermostat last week !
also now the electric fans run different, running for a few minutes after every shut down...

 

Coolant temperature sensor already checked?
Kann man ja per Bluetooth OBD Stecker prüfen.

 

Based on your description of the cooling module continuing to run after the vehicle is parked, it would seem the thermostat if faulty, or the system has trapped air.

 

SOLVED
BY REPLACING THE LOWER AND UPPER PLENUM GASKETS
the problems went away, the lower gaskets were squashed flat after 20 years and wouldnt seal untll the engine had a little heat...

thanks to all !

 

Thank you for the positive feedback