Q: Generally speaking, would a cracked crank shaft pulley be replaced during a full engine rebuild?

asked by on

We had our engine rebuilt and when we brought it home the mechanic said we needed to replace the crank shaft sensor. We did so and about a month and a half later the Jeep wouldn't start and idle. After testing found that cylinder 2 was dead and the rest had low compression. After this the computer ended up shorting out and then they blamed that on an "improperly seated crank shaft sensor". When we pulled the engine and all of that a part, we found the crank shaft pulley was cracked along the inside and that cylinder 2 was bright and sparkly silver color while the rest were all black. According to the shop that rebuilt the motor, this happened to the cylinder because gas was let in there from a faulty sensor. So I don't know if this is possible or true but my theory is much different.

My car has 209000 miles.
My car has an automatic transmission.

Hello there, this seems like a rather complex situation with everything that has happened. I will answer this the best I can with the information given. The crankshaft sensor could cause the vehicle to not start, but if it does, it would idle erratically. The ECU uses the information from the crankshaft and camshaft sensors to fire the proper cylinder and the proper time. The computer may become damaged if there is a short in the wiring such as with the crankshaft sensor. If a cylinder is not firing but the fuel injector is still spraying fuel into the cylinder, it can cause what we call a fuel wash. The fuel in this case is unburned and will clean the cylinder resulting in the clean cylinder you have noticed. Either the cracked crankshaft pulley or the crank sensor or the computer could of caused this misfire among other issues. It sounds like a few different issues contributed to the engine failing. With everything going on, you may want to have a professional inspect the car firsthand to verify what happened and advise on how to proceed in this situation.

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
  1. Home
  2. Questions
  3. Generally speaking, would a cracked crank shaft pulley be replaced during a full engine rebuild?

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

Q: Useless heater, live in a cold region

It sounds like this could be one of a few problems. The heater on your Jeep Wrangler gets heat from the engine(provided it has a gas engine). Two coolant lines from the engine flow engine coolant through a heater...

Q: Misfire in number 4 cylinder

If the injector tests good, I would check the voltage at the connector and check for a good ground signal from the PCM. This is often done best with a noid light. They can be purchased from most auto parts...

Q: replacing a crankshaft sesor in a suzuki XL7

Hi there, thanks for writing in about your 2008 Suzuki. It may be caused by a timing belt that has jumped a tooth. A bad crank sensor will typically cause the ignition to not fire at all. For a more...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...