Just changed my spark plugs for the first time--went with champion 3344--any way when I pulled my coils 3 of them had slight, not very deep, cracks in the bodies--should I start scrounging up some new ones? Can't see that it is causing any misses--she has been running great since sparkenzap helped me sort out the other problem. Also on coil #4 the spring on the plug end of the boot fell out. I got it back in to the best of my ability, but it is not the way it should be--but car seems to idle fine. Next is the inline fuel filter--it is in the boot correct? is there a way to, or do I have to, relieve fuel pressure before I change it? Thanks and have an enjoyable Columbus Day.----Scott

 

Fine cracks in the coil casing is very common. Most of the coils in both the X300s here have them. As far as I'm aware, they shouldn't have any ill effect on the operation of the car.

At one stage I had reason to believe that cracked coil casing was allowing electrical arcing from the coil to the rocker cover, thus accelerating corrosion. However the positioning of the cracks and the badly corroded areas was not consistent.

If you are really concerned, you could fill the cracks with epoxy. I certainly don't recommend wasting your money on another set of coils. They aren't cheap.

I don't quite understand what happened with your coil 4. Did the whole boot come off?

 

thanks for the input on the coils--I don't want to replace unless I truly need to. In reference to the coil-boot---on each end, inside the boot, there are small coil springs which sit on a either end of a metal rod, which appears to run through the center of the boot. It was one of those springs on the end that goes over the spark plug that fell out. I simply placed it back inside the hole and pushed it down with the small end of the spring on the metal rod. This in effect set the larger end of the spring over the spark plug----sounds confusing as I write this. I have seen coil-boot rebuild kits and I suppose it has something to do with this type of thing happening.

 

I've had the coils out of both the X300s here, and there was only one spring per coil. It should go: Coil -> Spring -> Aluminium Rod -> Spark Plug.

If you have a spring on each end of the rod I'm sure the lower ones were not there originally.

It would be great if someone else could confirm this...

I must admit that I never thought the rods made very good contact with the plugs, especially once the ends became corroded, so it's quite possible that the previous owner of your car tried to 'improve' that system by putting springs on the spark plug end.

 

the spring extra spring was only on coil four. No misfire or anything so I just left it there. I will just keep my eye on it. Thanks----scott

 

Fuel filter can be a pain to remove. It's under the car, sort of above the left hand halfshaft and not easy to access at all. Ideally, you need lots of penetrating oil and leave for a while. I wouldn't advocate using heat on the nuts due to the risk of fire. You could use those plumber's wrenches -the sort that are open ended ring wrenched - I forget there correct name and the sizes you need. They didn't work for me though. I ended up having to replace the whole fuel line from filter to engine - another difficult job. Try to get mole grips around the nuts and squeeze them in different directions and see if that breaks any seal caused by corrosion. Then try those open ended ring wrenches.
I don't relish jobs like that.


Just a thought, but perhaps you come from a warmer climate where corrosion is not so much of an issue.

 

Thanks for the info straight6. I do not anticipate any rust---very little at least---as I am close to the coast, but the car spent its life about 400 miles north of here in central Texas and cars accumulate very little rust. I guess I will just have to get under there and take a look---thanks again.