It's something Ive always been wanting to do but I do get scared of damaging anything especially when my dad tells me off for topping up my own oil and brake fluid.

I am going to try to the battery myself it doesnt seem complicated, not with the help of a YouTube video

 

Turns out the battery in my car was the wrong one. It was 720 CCA instead of 790. Going to install the new one today.

 

SannaT: After replacing the battery, you'll need to reset a few features. Very quick and easy, described in this thread:

https://www.jaguarforums.com/forum/x...cement-144778/

 

The CCA (Cold Cranking Amps) rating wouldn't affect anything, unless you are trying to start the car in extreme cold. If you needed a new battery it would be because it isn't holding a charge and not outputting the correct voltage. It wasn't that it was the "wrong" battery, that is unless you had something that was meant to be used on something like a riding mower.

How old is the battery you currently have in your car?

Once you get the new battery in see what you have. Read and then clear any codes that show up and see if any come back. Post here whatever coes show up.

 

The battery was 17 months old it started with giving me problems when it was cold.

 

I fitted the new battery yesterday. It's still rough idling when the engine warms up but I haven't checked for any codes yet

 

SannaT: Is the check engine light on? If 'yes', then definitely check the codes and let us know what you find.

Is it rough only when idling after the engine warms up? What about at highway speeds, and also when idling before the engine warms up?

 

There is no engine light. Sorry it's only rough idling before then engine warms up. Once it's warm it runs perfectly. I haven't taken it fqr enough to drive above 100km/hr but it still drives well especially when I chuck it into sports mode

 

SannaT: Reading thru this thread, the common theme is a rough idle before the engine warms up. Back in post #3, avern1 suggests the problem could be either a vacuum leak or a dirty MAF sensor, and JagV8 agrees in post #7. I'm on the same page. Here's why.....

The symptoms you describe are a rough idle when cold, a smoother idle when warmed up, and good performance at highway speeds, with poor gas mileage of 16.5 L/100km (~14 MPG) on a relatively high mileage engine - 190,000km (~120K miles). This sounds like a vacuum leak that is allowing extra air into the engine, causing a lean fuel / air ratio.

A cold engine prefers extra fuel, aka a rich fuel / air ratio, until it warms up. But the vacuum leak allows extra air in, causing a lean fuel / air ratio, so the cold engine idles poorly.

After the engine warms up, air still leaks in, so the fuel / air ratio is still lean, but the warm engine tolerates this better and idles more smoothly than when cold.

So why does the engine with a small vacuum leak run well at highway speeds? Because it 'inhales' 3-4 times more air than at idle, like a runner breaths faster than a walker. The fast breathing engine barely notices the extra air from the vacuum leak. The gas mileage suffers, but the performance can seem ok otherwise.

avern1 suggests three simple remedies back in post #3. Take a look at them and tell us what you observe. They're inexpensive and common for our X-Types. The post below has additional info on 2 of the 3 remedies avern1 suggests. If these remedies don't pan out, let us know and we'll walk you thru checking the fuel trims with your Torque app.

https://www.jaguarforums.com/forum/x...1/#post1309725

 

Thanks will try them