Hello Folks,

2013 Mini Cooper S Automatic 78,000miles

Died on the highway the day after Xmas. Full lose of power, coasted onto the shoulder, oil light as I was coasting to a stop. No horrible noises when the car lost power or during coasting. Once stopped I opened the hood and found the engine soaked in oil and the dipstick pushed up out of the tube. Vehicle was towed a mechanic I have never used because I was out of town for the holidays. They assessed that the timing chain failed or lost tension and are quoting me to remove the head, change the valves, change the timing chain, tensioner, and guides. I am fine with all of this, but the bill is very large and they are saying once they take off the head, they need to see what kind of damage the pistons have, and I may need a whole new engine.

My questions are:

• Does it make sense that the dip stick would blow out from a failed timing chain?
  • I do not understand how that leads to the high crankcase pressure, unless a piston cracked from hitting the valves.
• Is there other tests that should be done to determine if I need an engine vs just head/valve work, before putting in the effort to pull the engine apart?

Thank you in advance for your thoughts and input. Hope you all have a great new year!

 

Did they use a borescope to perform a cursory look at the valves, piston tops, and cylinder walls, or was the assessment based purely on external observations?

 

No. I asked them to scope what they can so we could better decide if a new engine is worth it before investing the time into removing the head. They said they would try but claimed their scope wasn't great. It has been a few days since I requested that and I have not heard anything further. Best I can tell and based on what they told me, their assessment is was purely on a visual inspection w/o removing an single part.

 

If the timing chain failed (or lost tension) and valves and pistons made contact you will be very lucky if the engine is not deemed scrap.

Even if not besides valves new pistons will be needed and new rings and it is generally a good idea to give the bores a clean up cut and proper finish to help the new rings seat. And since one is there new main and rod bearings for good measure after one checks the clearance to make sure no main or rod journal is worn too much.

Think your comment regarding the dipstick popping out due to excessive crankcase pressure arising from a cracked piston a reasonable one. I can't think of any other reason. I mean for "testing" compression of heavy equipment it is a SOP to with the engine running to remove the dipstick and feel for any pressure from the tube. This in some way lets one get some idea of the condition of the rings/pistons/cylinders.

Not too comfortable with the shop's reply to your request for a bore scoping of the engine: "They said they would try but claimed their scope wasn't great."

The shop's job is to have the right tools good tools and to know how to use them. If they have a lousy bore scope what else in the tool box is subpar?

Have you considered taking the car to another shop one which you know and know is a good shop?