2008 Ford Ranger 2.3 Duratec

[TXUSMC]

These engines don’t have keyed crankshafts. The timing is only secured through tension on the crank pulley. My son started the engine with a wrench on the crank bolt and it backed the bolt out. The crank kept going but the cams did not and the pistons collided with the valves. I was able to get a scope in the cylinders and I can see half moon shapes from the valves but nothing major. Valves are clearly bent so I’ll get the head off to get a full assessment. It has to come off no matter what.

[Gerald G]

Some pistons have the moon shaped indention machined in them, What you saw may not be from pistons and valve contact, but you need to pull the heads and go from there.

[justletmein]

Sounds like progress! Keep us posted!

[91cavgt]

It’s a chain driven engine

The same thing can happen on a chain driven engine. I know of an engine(GM 2.2 OHV motor) where it is common for the chain tensioner to go out, and it causes all kinds of problems until the chain breaks. In that motors case though, it is a non-interference engine so no damage is done when that happens. It is getting harder and harder to find a modern engine nowadays that is not an interference engine, so when there are timing issues, it is common for pistons to kiss the valves.

[Kingfisher789]

Why did he have a wrench on the crank bolt?

[TXUSMC]

He was turning the engine over to see if he could identify any up and down piston/rod play causing a “rattle” between 2000 and 2400 RPM. Evidently some of these engines have butterfly valves on the intake manifold that will start to rattle. This engine doesn’t have those so eliminating bearing slop was his next troubleshooting step. He left the wrench on when he started it so it destroyed his fan and slipped the timing. College kid working 30 hours a week at Discount Tire trying to work on his truck at night in an apartment complex parking lot. The opposite of ideal.

[Kingfisher789]

Dang the bad luck! Your choice of the word “ induced” seems appropriate. All I can add is tell him to study exactly what the procedure is going back together with it in respect to the crank bolt. Some of that family of ford engines have a very specific procedure that if you don’t follow it you’ll get bit!

[TXUSMC]

We have the cam alignment tool and the crank stop bolt to get it timed properly. I have done it once successfully and feel confident. We will surely be “making a list and checking it twice”! Merry Christmas to all!

[TXUSMC]

We got it taken apart this morning. Bent valves on every cylinder. There are clear impacts on each piston but no holes and the cylinder walls look good. $180 valve job plus some gaskets, a new fan and a new knock sensor, should be in it under $500 not counting my time.

[bowhntrmatt]

awesome news! I did a quick look and saw that most parts for this engine seem cheap and available, so I figured you'd have it back running quick. Hopefully the impact didn't mess up any piston rods or wrist pins.

[TXUSMC]

It happened on startup and only for a few seconds so I’m hopeful there’s no issues beyond the head. We’re gonna find out! I’ll update after the new year when I get the head back and the engine assembled.