4.0 sohc timing chain rattle

[Firemn260]

So the kid I just bought my 03 from said it was making some noise but after running it around the farm the last few days I didn’t hear it until this evening. It is definitely coming from the front of the engine, either the chain off the crank or the right side. It goes away when you bring up the rpms but comes right back when it is at idle.
I ordered some new tensioners but I’m still thinking the worse with the chain guides.

My question to you guys with experience in this issue, is there a chance this racket it’s making is just from a un tensioned chain slapping around or am I at the point where the damage to the guides is inevitable?
i anticipated the worse when i bought the truck and have done a lot of reading about this issue. The tensioners will be here middle of next week but I guess I’m just looking for encouragement from you guys and just start prepping to pull the engine now to do the whole timing system.

 

[Uncle Gump]

The lower oil pan can be removed fairly easily. The condition of the chain guides can be determined by the amount of trash in the pan.

 

[gw33gp]

When I rebuilt my cam timing chain system at 250K miles, the only thing broken was the mechanical tensioner for the chain that goes from the crank to the jack shaft that drives both the front and rear cam chains. That tensioner was totally broken off and laying at the bottom of the timing chain cover and it appeared it had been broken for a while. There was no rattle to indicate it was broken but I do recall a weird rattle once when leaving a check point near White Sands one time. That rattle went away quickly and never came back again. It may be that is when it broke and got jammed into an area out of the way.

That crank/jackshaft chain is at the front of the engine but is in the middle and down lower than the plastic cassettes that tend to brake. Some early 4.0 SOHC engines also had a chain the drove a balance shaft that drove a balance shaft. It was on the right side (passenger side) down low. I don't think any of those engines were in the Ranger. My 02 did not have one and everyone I have heard from with a Ranger 4.0 SOHC do not have one.

 

[SenorNoob]

Balance shaft just sounds like something Ford would have done for NVH in the Explorer for the soccer mom types...

 

[sgtsandman]

One thing you could try is replacing the tensioners and see if that fixes the problem. There is one under the throttle body for the driver's side and one on the back, outboard side of the head on the passenger side. You have to go through the wheel well to get to that one.

They wear out over time and should be changed out every 70,000 - 100,000 miles. Look for sludge in the oil passage way for each while you have the tensioners out. That can cause a restriction, not allowing the tensioners to operate properly.

If that doesn't work, then you are looking at finding out which guide is busted and cleaning out the debris.

Fordtechmakuloco has a four part series on replacing the timing chain guides and amazon sells the tool kit needed for cheaper than I've seen elsewhere.

 

[Firemn260]

I appreciate it. I’m going to pull the lower pan and see what’s what. I really don’t feel like pulling the engine but I think I’ll feel better replacing it all.

 

[Firemn260]

Well this in the bottom of the oil pan made up my mind to pull the engine out and do it all right.

 

[gw33gp]

That does not look like anything on the cam cassettes that I recall. If I had to guess i would go with pieces of the guides from the crank/jackshaft tensioner.

 

[Firemn260]

That does not look like anything on the cam cassettes that I recall. If I had to guess i would go with pieces of the guides from the crank/jackshaft tensioner.

I figured it was pieces of one or more of the guides in the front of the engine. I’m in the process of pulling the engine out now and just going to replace them all.

 

[Firemn260]

I know I started a few threads with questions and i apologize for that. I’ll just add to my original post from here on out about where I’m at with fixing my engine.
So as of today I’ve been able to get the engine out and onto the stand. I’m learning about the thing as I go along and I feel like I got a decent understanding of what makes this particular engine tick, or in this case not tick.
the jack shaft chain spring tensioner was completely destroyed. The pieces i found in the pan where from it. There was a lot of slack in that chain and I have no idea how it didn’t jump a tooth but I was able to verify that it didn’t with the otc timing tools. The slack in the chain however would seem to of been causing a variance in the valve timing. I did notice the plugs looked a bit on the lean side when I pulled them and also the driver side head seemed to have a lot of cooked oil in it. Passenger side looked normal. When I pushed the jack shaft chain back over to where it should be tensioned at, it would definitely move the cam shaft a degree or two. Other than the noise the truck ran and idled fine so I think I may have avoided and major damage to the valves.

Now onto the rear chain cassette. It was completely broken off and wadded up. The chain ground the mounting bolt down.

I have a cloyes timing kit ready to go in but it didn’t come with the one time use bolts so I’m waiting for them.

move been going back and forth with doing the head gaskets while the engine is out but to be honest I just don’t feel like pulling the heads. I know that’s not a excuse but we are just finishing planting hear at the farm so all I’ve been doing lately is turning wrenches keeping up with things breaking. I want to just get this engine timed and back in the truck but something is telling me I will regret not doing the heads.

 

[Roert42]

If nothing else that truck looks nice.

 

[gw33gp]

I did not replace the head gaskets on my engine, and it has over 05K miles on it now and still running strong. I did put a new oil pump in it and that improved my oil pressure. I also had to replace a few exhaust manifold bolts that were broken.