As rare as this is I would think the primary cause would be associated with either overheating or rapid cooling . Considering the difference in material between the head and the seat and the expansion difference along with the mileage that's where I would look. Usually the seats get pounded in over time so unless the tolerance was marginal when the seat was pressed into the head this would be the reason I would expect the failure.

 

my ignorance has been corrected once already in this thread, let's go for two: so if the SC engines don't have the variable timing, and if there isn't already a set of very obvious marks for timing, then shouldn't you be free to simply paint-pen the chain and the gears?

 

My problem was heat related. Sam, maybe one of your cats is getting blocked because you had that injector problem earlier? That'll do it. Too much unburned fuel out the exhaust and straight into the Cat. A failing cat will absolutely heat up the head.

 

Reverend Sam,
Of course, I watched your videos and read hundreds of your comments when I was active on the X100 forum. I dare say that since I got my X150, I just can't bring myself to drive the X100. The ride is so bad in comparison, the handling at speed is positively frightening, and the knee knocking and the seats just not as comfortable. I can't bring myself to sell it, because what could I get for a 175,000 mile 2002 XKR, maybe $4000? (even though the exterior looks like brand new). It's been sitting collecting dust in my driveway for the last couple of years, just looking ugly. And I just couldn't even bring myself to wash it. Last week I had to have it smogged for the new registration, so while it was at the shop (my regular mechanic and body shop), I asked him to have it compounded and detailed, When it came back, I realized exactly why I loved it for so long. It's just so classically beautiful and certainly carries its XKE heritage for all to see. But even driving it up the driveway, about 40 feet, I realized why I love the X150 so much more. There is just a level of refinement that makes the X150 a modern car. (Having an extra 200hp certainly doesn't hurt either). It would be a shame for you to have to give that up by parting out your car. If I can help, it would be my pleasure. My old engine is just sitting on a stand in my mechanic's shop gathering dust, if it will help you get yours back on the road, please feel free to contact me.
Ted

 

I have no idea what you're talking about. It's perfectly fine to chop vegetables on granite countertops. If they get scratched they can be polished. It's not improper at all.

 

When I was sitting in the parking lot with the engine idling BADLY, I thought maybe someone had stuck a banana in the tailpipe. I got out and felt the exhaust from both sides. The right side was just puffing away, but the left side was just going pfft, pfft, pfft. I could feel the exhaust gasses, but they weren't nearly as strong as the right side. I also smelled the rotten egg smell of a bad catalytic converter.

I used my OBD app to read the cat temps and they were both identical. Literally identical. Which made me think that the app is only reading the temp from one and displaying it as the temp for both. I can't imagine that both cats would be the exact same temp, especially when one side of the engine has a valve that never closes.

In hindsight, after the dealer said the valve seat was bad, I assumed that the difference was due to the bad valve. But it's definitely something I'm going to check.

I've spent most of the day cleaning out the garage so I can actually work in it. I bought some wheel dollies on Amazon so I can move the car around. They are supposed to be here tomorrow. It's the end of the quarter at the office so I have a lot of "real" work to do over the next two weeks. I'm not sure when I'll get started on the car. But I'll be starting soon. This should be interesting.

 

Get a lot of good cameras and a lot of light. Make a full-length movie of the whole shebang.

 

The issue isn't the granite, but the dulling of the knife blades and if it's light colored, possibly staining from vegetable juices.