Q: Failed engine, flywheel came off as well

asked by on November 02, 2016

Got a customer's car that broke 2 pistons and bent 2 conrods about a month ago. Customer took the car to another workshop to do the repairs, they replaced 2 pistons, 2 conrods, one valve that broke off the head and got jammed into one of the pistons, the cylinder head was damaged and broke a water gallery that caused the customer to keep adding water prior to the final demise of the engine and as he stated the water kept disappearing, which means there was already some sort of cylinder head damage occouring and water mixing in the sump (hydro lock?) When the engine broke the engine locked and seized.

Now a few weeks after this was done they have called saying the flywheel came off the crank, sheared all the bolts clean off the crank. They claiming we did the clutch repair back in June this year and the flywheel wasnt torque'd right which is BS as the remaining bolts in the crank are still in place with loctite and were torque'd as per the manufacturer specs with new bolts i might add.

Hi and thanks for contacting YourMechanic. When an engine is seized at an instant, especially when the engine is under a load, the flywheel will cause a big jolt. Now, the weight of a fly wheel is heavy when it comes to a rotational direction. With that said, as the engine is stopped at an instant, the flywheel will continue to rotate. If the bolts were new, the flywheel may survive the engine damage and just crack one or two bolts. However, if the bolts are used and old, then the flywheel will shier off the bolts. This has nothing to do with a loose bolt. A loose bolt will cause a vibration and make a ticking noise as the engine is running. In my career, I have seen cracked and broken flex plates, but have not had a flywheel come off due to non-torqued bolts with locktite on them.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

The engine klunking and tapping, needs engine replacemet

The reason the shops told you to replace the engine is that they do not overhaul engines. They can only replace it for you with a remanufactured or used engine. An overhaul is a third option but would most likely...

P0306 code after replacing COP, wires and spark plugs. What else could it be?

There are several possible causes for an engine misfire. There could be an injector problem, a wiring or connector problem, a PCM problem, or even a problem within the engine. Some further diagnostics will be necessary to locate the cause....

Hi Russell, I have a 2005 RX8, which I love!! It's in excellent condition, 80k miles. My teenage son blew my engine, can you do s

Hello Mary, thank you for writing in. The vehicle will need to be inspected before we know what needs to be done. Most of the time, the engine can be repaired, overhauled or rebuilt, or replaced (worst case scenario). An...

Related articles

What Is the Difference Between a Water-Cooled Engine and an Air-Cooled Engine?
There There are a few main differences between a water-cooled and air-cooled engine. Air-cooled engines utilize an engine cylinder design that incorporates cooling fins all the way around the cylinder and on top of the piston cylinder head. These fins...
Top 10 Ways to Extend the Life of Your Car
Every driver wants a car that lasts a long time. Make your car last longer by checking your motor oil, parking in the shade, and keeping it clean.
How a Modern Engine Works
You You turn your key in the ignition, and the engine fires up. You press the gas and the car moves forward. You take the key out and the engine turns off. That’s how your engine works, right? It's a...