2005 4.0L SOHC is toast. Have you ever seen this?

[hvanorden]

So I'm pretty sure my motor is toast. While driving it the other day I heard pretty loud "clank" and the motor died instantly. When you tried to start it again it would turn over and you can see the serpentine belt spinning so I knew the crank was spinning, but it sounds like there is absolutely no compression in any cylinder. I assumed it was a timing chain issue. So I opened it up and sure enough the front main timing change tensioner self destructed. The crazy thing is that it somehow caused the keyway that holds the lower timing chain sprocket as well as the crankshaft pully to the crankshaft completely broke right at the timing chain sprocket.

From what I understand, this is an interference motor, so the motor is toast. Has anyone else experienced this before?

 

[rickybobby]

unfortunatly it isnt that uncommon. If you are lucky the cam stopped in a position that didnt kill your pistons. The only way to know if it is beyond repair is to pull the engine and tear it down.

 

[boominXplorer]

Wow that's new to me. Looks like the chain stopped and the crank wanted to keep going. Something up the line broke to cause that, any pictures under the valve covers?

 

[hvanorden]

Wow that's new to me. Looks like the chain stopped and the crank wanted to keep going. Something up the line broke to cause that, any pictures under the valve covers?

No pics of under the valve covers yet. I'm going to start the process to pull the engine tonight after work. Once I get it out I will start taking it apart and will post more pics as I go.

 

[2000StreetRod]

failed primary tensioner?

Normally there is no engine damage from a failed primary tensioner because there is not enough slack in the chain for it to slip. Your photo testifies to just how strong the timing chains are. I suspect you will find something that prevented one of the camshaft chains from rotating. I would not purchase any parts for your engine until you determine the extent of the damage. You'll need some way to check for valve and piston damage. Do you have access to an optical probe? If not, you can use an air compressor with a spark plug adapter to check each cylinder for compression assuming you can get the piston and valve relationship correct for each cylinder. That might avoid pulling the heads and the associated cost of replacement bolts and gaskets.

If there is significant mechanical damage a replacement engine from a salvage yard may be less expensive than rebuilding the current engine.

 

[hvanorden]

I ordered a replacement engine today from a junkyard in Kentucky. Cost me $1500 with shipping and it came out of a wrecked explorer with 33k on it. I'm pretty happy with the price since most other motors I looked at with higher mileage were more like $1700 before shipping.

I plan on pulling out the other motor on Friday and taking the heads off to see what kind of damage there is. I'll post pictures through out the process.

 

[hvanorden]

So now the thanksgiving is behind us, The junk yard finally got my new motor pulled out of its original vehicle and it is in the hands of the shipper! Hopefully I'll see it soon.

One question, I need to confirm this with the junk yard, but based on the fact that it only has 33k on it and it's coming out of a 2005, I'm assuming that the motor has been sitting in the junk yard for a while. Is there anything special I should do before putting it in my explorer and firing it up? Do I need to be worried about leaky seals?

 

[hvanorden]

Finally got the new (used) motor. It's not too pretty. Looks like it may have lived most it's life near the coast, but no major damage that worries me. The junkyard left a bunch of parts on it that I didn't expect to receive. Intake, PS motor, fan, and a couple other small things.

I almost got the old one out last night, but there is one bell housing bolt that is really hard to get too. I finally was able to get it by using 4ft of extension!

I'm hoping to get the old engine out tonight and get the new one in an running no later than Saturday (today is Wednesday). Once the Explorer is running again I'm going to throw the old engine on the engine stand and start taking it apart. I take pictures of any damage as I go.

 

[2000StreetRod]

inspect balancer

I suggest that you closely inspect the harmonic balancer. Some of the 3rd generation Explorer balancers have a failure problem: Harmonic balancer failure

 

[mjstef]

Is that a box bronco i see in the background???

 

[hvanorden]

I suggest that you closely inspect the harmonic balancer. Some of the 3rd generation Explorer balancers have a failure problem: Harmonic balancer failure

The harmonic balancer actually already fail on my explorer about a year ago. So it is fairly new.

Though it makes me wonder......it failed while my wife was driving and I was out of town and out of cell phone service. She got it towed to the closest shop to where she was in Denver and they totally took advantage of her not knowing anything about cars.

When she picked up the explorer and drove off it failed again about 20 minutes into the drive. So she had it towed back and they claimed that it was a "faulty part" and replaced it again (charged her again too!). I've been wondering if they did something in there to cause the issue I'm having now? It's probably pretty far fetched, but this was the shadiest shop ever.

 

[hvanorden]

Is that a box bronco i see in the background???

Yes sir. It's a '75 bronco ranger. I am in the middle of doing an auto to manual tranny swap. I pulled the C4/dana 20 combo and I'm putting a NP435/NP205 combo in it.

Unfortunately that has all been put on hold thanks to this explorer project!

 

[mjstef]

Yes sir. It's a '75 bronco ranger. I am in the middle of doing an auto to manual tranny swap. I pulled the C4/dana 20 combo and I'm putting a NP435/NP205 combo in it.

Unfortunately that has all been put on hold thanks to this explorer project!

The old granny 4 spd makes a monster out of them!! I had the same setup in mine. Sold it in 09 to start a business when work was slow. regret selling it to this day!!!

 

[hvanorden]

This is sadly the best picture I have of my Bronco. It has been a work in progress for over a year now. I bought it from a guy who abandoned it in a field for a few years.

 

[mjstef]

This is sadly the best picture I have of my Bronco. It has been a work in progress for over a year now. I bought it from a guy who abandoned it in a field for a few years.

Looks like it has good body panels! Even out here in the mountain west that's kinda unusual as they where REALLY bad about about attracting rust moths......

 

[hvanorden]

The old granny 4 spd makes a monster out of them!! I had the same setup in mine. Sold it in 09 to start a business when work was slow. regret selling it to this day!!!

I had an NP435 in my '72 f100 and I'm sold on those transmissions. The granny gear is awesome! and they are bulletproof.

 

[hvanorden]

I made some good progress tonight. I got the old engine out of the explorer. I have the day off tomorrow, so I'm hoping to get the new engine in and running again.

 

[hvanorden]

So I got the new engine in and I'm proud to say that it started right up no problem! I was incredibly relieved! It drove nice and I was feeling really good about everything. This morning I went out and warmed it up to drive it to work today and when I went back out to take off I noticed it was leaking fuel. So sadly she's spending yet another day in the garage. I have no idea why it would be leaking fuel and I could tell where it was coming from since I was wearing a suit and couldn't get under the vehicle. I'm hoping it's not a big deal and I can fix it tonight.