Is it the timing chain?

[Dorn]

Looking for some help I bought a 1998 explorer sport 4.0 sohc first time working on one. Got it for cheap because it didn't run the guy didn't know why. I got it home and turned the key for the hell of it and it actually started by was running really really bad I don't know how it even ran at all. I heard a bit of knocking/clanking and shut it down. Took compression tests and driver side was all good but all 3 passenger side were 40-60 psi. That means timing chain on these right? Is the motor interference? Is it shot already anyway? If not my friend told me but is there actually a chain in the rear for the passenger side timing and the motor has to be pulled anyway? Any info or advice is greatly appreciated

 

[david4451]

Sorry to say but the engine is toast, the passenger side timing chain has jumped time and bent the valves. This is due to failure of plastic cassette parts.

 

[koda2000]

Yes it was the timing chain that did the damage. Junk it or find yourself a replacement engine. That one is done.

 

[RandomNerd2000]

If it's clean, and you're inclined, find yourself a cheap engine out a rollover or rear end wreck, and drop it in, that's what I've got done for when mine finally kicks it.

 

[Dorn]

Thanks for the replies! I guess I'll have to see about a motor

 

[RandomNerd2000]

Here, a good 4.0 runs about $400, mine I've got I paid that for, it came out a 99 2 door, 2 owner, 136K, I had one with 102K on it, but I got an offer for it I couldn't turn down, and the car it came out of was really rough.

 

[Dorn]

OK so I've read on a couple different sites that the 4.0 is not an interference engine and won't bend valves. I know some of you guys know these like the back of your hand so can someone confirm that truthfully? Of course I know everything on the internet is true. Kidding. Now if it turns out true that the valves wouldn't be bent am I still looking at pulling the motor because the passenger side is the chain that's junk?

 

[96eb96]

It is an interference engine

That being said the chain really has to jump time to bend valves.

Since you likely have a rear chain (4wd does because of the balance shaft) the motor has to come out anyway. Good idea to put new timing parts on the new motor.

The SOHC motor is junk unless a ton of work is done to it. Hope you did your homework here.

 

[david4451]

Get a boreoscope and look at top of pistons for valve marks.
The engine needs to come out to replace right timing chain casette.

 

[Dorn]

Ok great answers thanks a lot! Not sure what I'll do yet but either way it's going to be some work I guess.

 

[koda2000]

The 4.0L SOHC is most definitely an interference engine. Why do you think you now have no compression on the passenger side? The valves on that side are now bent.

 

[Dorn]

Well I'm not an expert that's why I asked but the partial compression readings the me off I thought maybe I would only get zero compression of the valves were bent

 

[Dorn]

So I found a 4.0 on Craigslist that came out of a 1999 ranger. Should that basically just bolt right into a 1998 explorer sport 4x4? Thanks everyone

 

[boominXplorer]

Different engine. The ranger didn't get the 4.0 sohc till 2001. 2000 and previous was the 4.0 ohv which is completely different.

 

[Dorn]

Seriously! Wtf! Could've got it for $300

 

[swshawaii]

OK so I've read on a couple different sites that the 4.0 is not an interference engine and won't bend valves.

OP, I would assume this is the article you read. IMO, informative with this one glaring mistake.

Being posted April 2013, very surprised it hasn't been corrected.

Fortunately, the 4.0L SOHC is not an interference engine so a timing chain failure won’t bend the valves.

Ford 4.0L V6 Engine - Explorer, SOHC, Timing Chain

www.underhoodservice.com

 

[Dorn]

Different engine. The ranger didn't get the 4.0 sohc till 2001. 2000 and previous was the 4.0 ohv which is completely different.

Do you know what years and models I would have to look for? Explorers only? Thanks

 

[Dorn]

OP, I would assume this is the article you read. IMO, informative with this one glaring mistake.

Being posted April 2013, very surprised it hasn't been corrected.

Yes that was one. saw in another place but I wasn't trusting the info

 

[koda2000]

Any '97-'11 Explorer SOHC 4.0L would work as well as the Mustang 4.0L SOHC (not sure what year Mustangs). You'd want to keep/refuse all your original peripheral equipment.

BTW: I wouldn't consider a used 4.0L SOHC engine w/out first replacing all the timing chain components. It's not IF these engines will develop timing chain problems, but WHEN

 

[jbl0072k2]

Doing the same. Drivers side cam shaft chain only. Most of front engine taken off now, engine in truck. Now pull the crankshaft pulley off with a removal tool right? Then pull covers, and wiggle broken plastic tensioner piece out, and replace?