i just bought a 2003 s type. i have been driving at various speeds and the car starts jerking or missing. the rpms are about 2k when this happens then drop to 15. when it starts jerking the rpms jump back and forth between 15 and 2k. if u punch it it runs fine and shifts good. i am thinking coil packs going bad but hasnt thrown a code yet!!!!!!! any help?????

 

You may not get codes although you probably will. It sounds quite serious and coils are #1 suspect. Do some searches as this is a very common issue and all the answers are on here.
How many miles on the car? Which engine?
What service etc history do you have?
Do you get a flashing MIL (CEL) at all?

In case it's a misfire, don't drive more than you must and do not "punch it" as cat damage is likely occurring.

Spend time reading posts on here for a few months back and you'll see the common faults and fixes.

 

it is an 03 v-8 with 118k on it. nothing flashing at all in the car. car runs an drives great. i am unaware of the service history on the car. i just bought this car last sat.

 

i did a search on here and everything i found was already throwing codes. mine is not.

 

The plugs should have been changed at 100K but maybe they weren't. The coils die with age so any/all of them could need replacing. You mean the 4.2 V8 NA, i.e. not the STR?
If you can do detailed OBD, do the usual checks - see previous posts, probably search on monitors and/or complete.
There are other possible causes but coils & plugs need to be right before hunting unless you can diagnose something specific e.g. via OBD.

 

As mentioned before, coils are the #1 suspect. A good fuel injection/induction cleaning comes in at #2, particularly if the car has never had one before. After all, this car is pushing 120,000 miles....

 

On the other hand, my identical year car with identical engine with virtually identical mileage does the exact same thing.

It's the transmission torque converter locking and unlocking. Mine only does it when the weather is exceptionally cold, and the condition goes away when the car is fully warmed up.

 

If your car is a 4.2 NA and in VIN range M45255-M84213 then have a look at TSB S307-13.

(I figured you'd already have considered TSBs.)

 

Ok if this helps it does it at warm or cold temps with sport button on or off...... Haven't noticed it with the manual shift. I don't know what (tsb's) are so no I haven't checked that. Also it has not been put on obd ( I am assuming that is a computer).

 

Try google with
TSB S307-13

 

Ok looked up tsb and mine has some of those signs. When coming to a stop and start again mine jerks almost like it gives you a good jerk. Is this a recall on the s- type? If not is this a costly repair? Another question ....... Are the coil packs to a 2000 Lincoln ls v-8 and the s type the same packs? They are the same codes. I plan on doing injector flush and plugs. Just curious to the packs

 

Ok looked up tsb and mine has some of those signs. When coming to a stop and start again mine jerks almost like it gives you a good jerk. Is this a recall on the s- type? If not is this a costly repair? Another question ....... Are the coil packs to a 2000 Lincoln ls v-8 and the s type the same packs? They are the same codes. I plan on doing injector flush and plugs. Just curious to the packs

 

I just got a 2003 V6 and mine seems to be doing the same thing yours is.. I thought it was weird since mine is only at 26K miles? I am going to clean the fuel system and hopefully that helps..

 

mjr, its what everybody else on here has described with the torgue converter. there is also a module on the transmission that gerts out of sync and causes these problems. i am having mine reprogrammed on tues to see iff that fixes everything. the dealership is the only one that can fix from what i have been told because other people dont have the computer for it.

 

^ thanks for the info! Hopefully that wont cost too much...

 

i dont know what the torque converter will cost but im taking mine in to get the trans synced. they quoted me a price of $250.00 to $300.00 for just that. (they being the dealer)

 

when they id mine, it was near 3000. thankfully i had an extended warranty that covered it minus the fluid and my 100 dollar deductible.

 

Bummer to experience issues already at 26k especially since the car was only driven in the summers by my Grandpa..Guess I expected more from Jaguar as far as quality? I will be heading to the dealerships to see what they can do for me and for how much.. thanks again guys for the help!

 

MJR - cars need to be driven regularly, and a decent distance at least once a month but preferably once a week. At 26K your car is unlikely to have issues with such as plugs but the lack of use can cause all sorts of problems which a car at 100K could easily not have. Greases stiffen and harden, damp gets in, things rust and corrode etc etc. Heck, insects, rodents and things nest or gnaw or ... well, you get the idea. Aircon seals dry up and then leak, so expect a/c problems. (None of these are unique to any make, whether jag or other.)

 

ok got the jag in getting fixed. a week and $1000.00 later and should be good to go. i had to get the tc fixed, the trans reprogramed and some idiot decided to put washer fluid in my power steering. so after next week i should be up and running.

thanks everyone for the help and knowledge. it really helped out.