I have a 2001 Jag S type 4.0 with 115,000 miles. I found out the valve cover gasket was leaking and I have 2 bad coils. I was told that you only change coils when they are bad but I have also read just change all of them. Should I just change the 2 or should I change all 8?

what brand of coil do you recommend?

 

I always just carried several coils in the car but I had dozens of good-used coils from working at the Jaguar dealer.
When one failed I would replace it and move on.

I would buy DENSO 6736004 which is likely the OEM part or MOTORCRAFT DG529 that is likely the same part???

The OEM yellow or green label parts seem to fail and the OEM black label parts (issued later) seem to last longer.

bob

 

carried them in the car? Are they that easy to change?

 

What is access like on the V8? On my '02 V6, access stinks to the three coils on the US passenger's side. When one of those failed, I swapped a known good coil from the other side. I then installed the new coil on the easily accessible US driver's side. I didn't want to risk finding out a new coil was bad from stock and have to tear everything apart again on the side with poor access.

Stick with a quality name brand. I think I went with Motocraft but can't remember for sure. Stay away from Fling Dung and similar bargain brands you might find on eBay and other sources.

 

Do them all. It is more work getting at them than is worth the saving of a few bucks. If one has failed, all will follow. Know this from several years of frustration after going cheap.

 

Access on the STR is a bit tight but OK. The V8 NA should be at least as easy (less stuff in the way).

The rearmost ones need a bit of wiggling.

I would only change a coil if absolutely necessary as they seem very good quality. (I have a spare I've not yet needed i.e. am still on the OE ones.)

 

17yr old, 115k miles, and your in the southern heat... if I were going to keep the car more than 1yr I'd replace all 8 and the plugs too. If going to sell the car soon, I'd just replace parts as needed.

 

I wish I would have just followed my gut and replaced all 8. I replaced the 2 and now the others are starting to go bad. ugh