My car starts, runs for 30 seconds, stalls. Mechanic tells me he coded it and it needs a timing chain. I have 200k miles on it. Does that sound right?

What code? How did it run? Did it make rattling on cold start?

Moved thread from the "Introductions for new members" forum to the "Buick" forum.

That'* an LLT 3.6. They weren't as well known for stretching timing chains as the LY7 before it.

What are the codes?

How many miles have you owned it?

How often (in miles) does it get its oil changed?

Thinking about it further, even stretched chains won't cause it to stall . . . unless they were stretched too far a 100,000 miles ago and it kept getting driven. If this situation just started, I'd be very surprised if the chains are making it stall.

How many miles are on the current set of spark plugs?

What is the fuel pressure when this happens?

It ran great until this happened. It was due for an oil change and needed the tire sensors fixed. No big rattle. Maybe a quiet little rattle.

Apparently there is a coding program that is run to detect what the problem is with the vehicle. When it was run on my Enclave it was determined the timing chain was the issue. My second concern is what else will go wrong after this is repaired. My Enclave does have 203k miles on it.

I've owned it for 150k miles. Religously changed oil every 4000 miles. I do not know the codes.

Original spark plugs. So 200k miles on them. Never changed them. I don't know the fuel pressure.

Change the spark plugs. They are 100,000 miles overdue. Nothing else will be right until this is done. I'm amazed it has made it this far.