Dear Tom and Ray:
The engine on my '97 Pontiac Bonneville FELL OUT while I was driving 55 miles an hour yesterday! Luckily I am fine. Had it happened mere seconds sooner, I would have been in a lake, as my steering and brakes were rendered useless. So, how could this happen? I heard a loud CLUNK first, and thought I ran over something ... in the rearview mirror I saw a round black thing bouncing on the road, and then quickly realized the engine had cut out, my steering was not working, and my power brakes were, er, powerless. The nice ditch stopped me. Have you ever heard of this happening? I thought stuff like this only happened in cartoons. Then again, it would not be so inaccurate to say my life is like one big cartoon, but I'll save that for Dr. Phil. Thanks! Love your column.
-- Robyn
Ray: Did the Check Engine light come on? Finally, a good use for that light!
Tom: I don't think the engine fell out, Robyn. But it could have fallen down.
Ray: You really can't run over the engine and see it bouncing down the road behind you. It's too massive. The car wouldn't be able to go over it. The car would have to flip over it in order to separate itself from the engine.
Tom: Here's what probably happened. The engine and transmission are held in a cradle, or sub-frame, that's bolted to the chassis of the car. For some reason, that cradle failed.
Ray: And when the engine and transmission assembly dropped down, it probably tore out the power steering lines, stalled the engine (which killed the power brakes), and the roadway probably sheared off the oil pan, which is a black thing that could have been rounded off in the process, and then bounced down the road.
Tom: It's very unusual to see the bolts that hold the sub-frame fail. They're massive. But its within the realm of possibility that they corroded due to a dozen-plus years of winter road salt. Or maybe the sub-frame itself corroded and broke?
Ray: Another possibility is that someone removed the cradle to do some work and didn't properly retighten those bolts. If you had any major under-car work done (engine, transmission, rack and pinion) in the past year or so, that could have required those bolts to be removed. And if they weren't re-tightened completely, over time they could have loosened up, worked their way out, until ... ba da bing! Major excitement!
Tom: Well, it's all oil under the bridge now, Robyn. But that's our best guess as to what happened. Glad to hear you pulled through OK, even if your Bonneville didn't.
(Car Talk is a nationally syndicated column by automotive experts (and brothers) Tom and Ray Magliozzi. Write to them at the Car Talk website.)
4 Comments
By Fritz Stout on December 10, 2010 6:05 AM
An easy answer would be to open the hood, yes? If there is an engine sitting there, it didn't fall out. If not...well, there's always a first time. I can't imagine that the car wouldn't be catapulted out of control if the entire engine block and associated attached parts were suddenly jammed beneath the undercarriage at speed.
By Steve C. on December 13, 2010 2:32 PM
Is it possible that the car could have been catapulted over the engine, but still landing on its wheels, rather than being flipped?
Sounds like a subject for Mythbusters!
By Mike on December 15, 2010 10:52 PM
Dear Click and Clack. That is the worst explanation, that I have ever heard from you. At the very least, you could have made up a better cockand bull story.
By FDH on December 19, 2010 3:56 PM
I would suggest, besides the obvious, open the hood and know for sure, that the large round thing was one of the pullies or crankshaft balancer. Pully breaks, or perhaps cam chain breaks, possibly the motor siezed and the crank broke. Without the motor, the steering is very stiff and the power assist to the brakes is greatly decreased.
I think the engine falling down sounds pretty good too, but you'd think she'd have noticed the oil and smoke?