Just wondering how common it is for the coil packs to go bad on these cars is it usually the boots or do the coils themselves go bad fairly easy??

 

I have heard that they do fail, mine are the originals at 163k kms. The boots may go off due to oil in the hole. The spark plug gap MAY cause them to work harder, MAYBE and that could cause early failure??.

I have read that some have had cracks, I suppose that is possible if it shorts internally, it will create huge amounts of heat.

I do know that when refitting mine I push them down home by hand and then fit the bolts, so as not to pull them down at an angle which will crack them obviously.

Apart from that NO.

 

As I've said before, in my experience the coil casing will crack up well before the boots. The boots are made of resilient rubber, and they last very well. The only thing you have to be careful of is if you need to remove the boots make sure you pry them off very gently. If you just grab them and twist/bend the rubber will tear (as you would expect any non-silicone rubber to).

Also, there is an aluminium rod that runs up the centre of them, so thats another reason to be careful not to bend them around.

In the two X300s here, I've not had any issues with the boots. Most of my coils have fine cracks in the casing, but they do not seem to cause any issues.

 

Thanks guys I was just wondering I had 4 bad ones some bad boots and a few with bad casings I got a new set from a wrecked XJ6 and one nice thing is 3 out of the 6 were brand new replacements from Jag hahaha someone paid a small fortune for those lol. I paid a 100 bucks for all 6 and they all work amazing, put those in after cleaning them up with some dielectric grease an new NGK iridium plugs. It runs so good and smooth woohoo