Can a con rod disconnect from piston because the bolts just came loose and fell off?

GYPSY DANCER

MEMBER
2000 BMW 540I
154,000 MILES

I took my car to Canadian Tire for an oil change. I picked it up and my wife drove gently around town for 14 km. She was idling up to a stop light when the car came to an instant stop. Motor now has con rod through side of block. Canadian Tire claims that the bolts came loose from the piston causing the rod to separate and go through block. The motor was running perfectly up to this point and had never been apart since new. There aws no warning, like overhaeting or anything like that. Car was running fine one second and comepletely destroyed instantly. The car move less than 5 feet stop.

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Why did you take it there? Was there an issue before this?

Roy

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Friday, September 21st, 2012 AT 5:07 PM

DOCDTC

MECHANIC
53 POSTS

Although possible- this is not likely, far more likely is lack of lubrication. Either the wrong oil or no oil was put back in at the oil change. Remove the oil filter and see it it is full of oil. If no oil is present in the filter housing, engine was not filled. I believe you have grounds here for a claim against the facility for engine damages. In 35 years of being a full time professional mechanic, I have yet to see rod caps come loose in an engine. For it to throw a rod through the block at idle, seizure due to lack of lubrication is the most likely scenario. A check of the other bearings in the engine will either support or refute this.