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I have a 1994 Jaguar XJ6 Is there such thing as engine auto lock if you have a head gasket problem to keep water and oil mixing? I brought my car in for brakes and they've had it for months of problems getting parts and lots of excuses and when i finally gave up on them and went to pick it up it wouldn't start. It was running fine when I brought it there. They told me last they started it, it was blowing white smoke and jags have a bypass or auto disabler of the engine so that it won't cause more damage so maybe that's why its won't start. Is this bulls***? Is there such thing as a hyper lock that makes it that the engine won't turn over? I want to call them out on their lies if this is a lie and have them repair it so I can drive it home like I drove it in there. thank you for any information you can give. Jim

Answers from the Automotive Experts

Jessica Howe, Automotive Expert & Coach at

Hello Jim, 

Being in a situation like this is never easy. Since your Jaguar is a 1994, it is highly unlikely the vehicle has a "hydro lock" keeping it from starting due to the described reasons. While I cannot verify that exactly, the dealership may be able to if you can talk to the right service manager. However, the issue you describe sounds more like a security system immobilizer, which often stops the vehicle from starting if the battery dies at some point. If they let the battery die, and the immobilizer was tripped, they would have to reset that system to get the vehicle to start.

The vehicle is also equipped with an inertia switch, which cuts off supply to the fuel tank in case of an accident. It can be set by hitting the wrong buttons and by driving recklessly. It is usually as simple as resetting or pushing the switch's button. 

It is incredibly difficult from our perspective to tell what may be stopping the vehicle from starting. But we would like you or your techs to check the immobilizer and the inertia switch first. 

If the vehicle was not smoking when you took it in, this is a good indicator what they describe is wrong. You can also check the level of coolant to see if it is low, and check the oil to see if it looks like coolant has mixed in with it. It would look muddy if this is the case. Good luck!

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