I'm looking to purchase a 2005 Jaguar XJ Super V8 with 86,000 miles. It has one owner and spent it's entire life in CA. It currently is with a very reputable dealer in CO. The salesperson started it for me in their climate controlled showroom and, upon start-up, a couple of big puffs of blue smoke came out then turned white for 15-20 seconds and then seemed to turn to a more normal exhaust output. The salesman did say the car had not been started in over a week, the car did start up immediately on the first crank and the car after 15 or so seconds did seem to idle nicely. Is that the first signs of an engine that is in need of a valve job and a new head gasket? Or could it be something more serious like a warped cylinder head? This is my first post, thank-you to everyone in advance for your responses.

 

First thing to do is see if there are any error codes.

I often do not start my car for weeks in the Winter and nothing like that happens.

Also check the oil dipstick to see if oil is clean and no milky deposits. Also the oil filler cap for same thing.

 

Unless the engine has been overheated at some point, cylinder head and head gasket issues are uncommon in the AJ33 and AJ34 units.

It may be best to have the dealership remove the vehicle from the showroom so you can drive it and see if there is anything that would indicate a problem, such as the MIL being on.

 

Same here. No smoke after not starting for several weeks in a cold garage.

 

Thanks for all the advice everyone, I'm picking it up today to take to a mechanic for a PPI.

 

If over heated, or if thermostat housing failed - causing overheat, you could have warped heads. I'd closing inspect the oil pan gasket for leaks also, as a sign of possible over heating. Check the maintenance records. You could also check cylinder pressure/leak down test to look for worn rings.

 

One possibility is worn valve guides.

I have seen a car or two that after sitting a while oil drains down the guides and sits on the pistons until start up when it gets burnt off resulting in dark smoke for a short while.