Engine locked up.

[twoiron]

Hello! I am trying to help My son repair his 1999 Explorer XLT with a 4.0L SOHC engine,auto transmission and auto 4 wheel drive. He said that as he was starting to climb a hill the transmission down shifted into passing gear,at that time he heard a "clunk",the engine revved up and then quit.When you try to start it up it just makes a loud click and the engine doesn't turn over. Any suggestions on where to start looking?

 

[Joe Dirt]

I'd bet the chain tensioners let go...

 

[2000StreetRod]

Engine seized?

The "click" may be the starter relay. The engine may be seized preventing the starter from cranking the engine. The first thing I would do is see if you can rotate the crankshaft using a socket and drive on the harmonic balancer retaining bolt. You may have a bent connecting rod.

 

[twoiron]

Thank You!,2000Street Rod. I'll try that as soon as I can. Accordin to the Haynes manual,you have to pull the engine out to work on the timing chain. is that true?

 

[2000StreetRod]

Not true

Thank You!,2000Street Rod. I'll try that as soon as I can. Accordin to the Haynes manual,you have to pull the engine out to work on the timing chain. is that true?

No. You can replace all timing chains except the rear right and the balancer chain without removing the engine. Check my helpful threads in my signature for more than you probably want to know regarding the SOCH V6 timing chain issues. The chains rarely break. They are much stronger and longer lasting than the guide assemblies. I'm not convinced yet that you have a chain problem since the engine downshifted and revved due to high load. Are you sure that you got the entire story? Was the vehicle going thru water? If so, it could have hydro-locked.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 95-01 section.