Hydrolock

[swtjames23]

Yep, sucked water in the intake, locked up the motor. Pulled the plugs, blew the water out, reinstalled plugs. Now the truck seems to run good but with a pretty loud knock (or tick? not sure the difference at this point). I pulled the valve cover off, pulled the rocker assembly and pushrods. Pushrods are straight. What would you do next?

 

[alwaysFlOoReD]

I hydrolocked a 7.3 diesel. Two bent rods.

 

[jeremysdad]

Yep, sucked water in the intake, locked up the motor. Pulled the plugs, blew the water out, reinstalled plugs. Now the truck seems to run good but with a pretty loud knock (or tick? not sure the difference at this point). I pulled the valve cover off, pulled the rocker assembly and pushrods. Pushrods are straight. What would you do next?

Probably a knock. Video would help...but most 'hydrolocked motors' kill rod bearings or bend rods. Sorry.

Sounds like you went into water above your headlights...for future reference, install a snorkel for such fjording.

Best of luck.

 

[swtjames23]

Yep, snorkel is on the way. Friend was driving as I rode his new quad. He was unaware of the intake behind the headlight, he's well aware now

I'll post a video when I get the top end put back together.

 

[RonD]

While engine is idling, pull off 1 spark plug wire at a time, if knock quiets down then that cylinder has bad connecting rod/bearing.

Hydrolock:
When an engine is running and a piston can't continue its travel to the top of the cylinder, cylinder has water in it, the piston comes to a sudden stop, with the rotating weight of the rest of the cylinders and crank still pushing on it.
The softer parts(bearings) deform and harder parts can bend or break(connecting rod and piston).
Valves could be effected but when a cylinder hydrolocks valves are closed or it would just push the water out.

Connecting rod bearing knock
When bearing is deformed(or worn out) there is a gap between crank journal and connecting rod.
This gap causes a knock but only when it's cylinder fires.
When a piston is in motion up on its compression stroke the gap is at the bottom, as piston passes TDC the crank starts pulling it down, so gap moves to the top, then the spark plug fires and KNOCK, as the gap closes fast and the metal to metal slap noise is heard.

Removing the spark would quiet the knock, if it is a connecting rod issue

 

[swtjames23]

Thanks Ron. Anybody ever pulled the pan and crankshaft without pulling the motor?


Sent from my iPhone using Tapatalk

 

[RonD]

That could be done, if trans was removed of course, since crank is connected to trans.

And if trans is removed then might as well just pull the engine out.

But not sure why you would want the crank removed in any case.

Heads need to be removed, then connecting rod bearing caps
Pistons and rods are then pulled out the top and each would need to be checked.
Wrist pin and piston on hydrolocked cylinder would most likely be damaged.

Crank damage with a hydrolock would be unusual, especially if engine still runs, i.e. no broken pistons or rods.

Just pulling the oil pan on a 4x4 is hard without lifting the engine up, even on 2WD it may not be possible.
And since heads have to come off, to do any repairs for this problem, you might as well just pull out the engine to make it easier and faster to work on.
Or find a replacement engine to put back in at that time.

Engine hoists are not expensive to rent

 

[swtjames23]

I didn't mean remove the crank, just access it. I figured it would be possible to change the rod bearing from underneath the truck as long as I could get the oil pan off. No?

 

[ratdude747]

I didn't mean remove the crank, just access it. I figured it would be possible to change the rod bearing from underneath the truck as long as I could get the oil pan off. No?

Yeah, but AFAIK the 4.0 requires engine removal to remove the oil pan.

 

[cp2295]

It does in the ranger/explorers not aerostars. In any case youre going to want to tear down the engine and inspect everything, the crank probably has damage on the journal, and the rod to. Metal flying around in your motor gives everything else less chance for survival


Sent from my iPhone using Tapatalk

 

[alwaysFlOoReD]

I doubt there was metal flying around, unless the piston shattered. When I replaced the rods in the 7.3, I bought used piston and rod assembly and put in new bearings on those two journals. It was still running around town 10 years later. If I had the motor out and the knowledge and place to do it, I would be tempted to do a refresh of the motor ; rings and bearings, but only if I had the time and money.

 

[swtjames23]

I can get a 95 motor w/ 100k miles delivered to my door for $500. That's a little tempting. The thermal isolator on that motor would fix my vapor lock issues as well....

 

[alwaysFlOoReD]

That would tempt me too.

 

[enjr44]

You have either a bent rod(s) or a broke piston(s). Pull it and get on with it. Worst banging I ever heard was after I dumped a running engine in the Missouri River.

Have all the rods checked at a machine shop. You maybe only hearing one; but, that doesn't mean there is only one.

 

[swtjames23]

This pretty much confirms it. Thanks for the input guys

https://www.youtube.com/watch?v=0a7UPN6xZzU