Timing Chain questions

[eqppwqqep]

I have the dreaded timing chain rattle. I have had it for 4 years and 50K miles. It has not gotten worse or better. It only rattles between 2500-3000 RPM. My truck doesn't have a rough idle or bad gas mileage. I have never had starting issues. It is just noisy.
I called Ford (as I bought the truck used with 52K on it) and asked if the previous owner had the recall done on the tensioners (there was a recall, right?). They said no such thing happened on this truck and no open recalls. I called my mechanic and he looked up the work in AllData or w/e he uses and the engine was not flagged as being an interference engine. He told me if it has been noisy for 4 years and 50K miles without getting worse and no issues with performance in that time, given the cost of the repair, he would recommend NOT doing the repair. I have read and read and poured over this forum on this particular topic for going on a year now.
Questions:

1 - Is the 4.0 SOHC engine interference?
2 - Is there an affordable fix, maybe leaving the engine in?
3 - What are the odds the chain might fail?
4 - Should I just live with the noise?

Now I know some of you will tell me that it is insanity not to have it fixed. Some of you will say it won't break. I don't know which way it might go, and I'm sure you guys won't know either. I am just looking for 1) an answer the interference question and 2) actually accounts of the chain breaking and how long it rattled before it broke.

I will tell you the majority of what I found on this site in the past 12 months was a lot of "I'll just let it be noisy" and a few "I'm a mechanic and can pull an engine relatively quickly to do the repair". I feel I can do this repair, I just can't justify it without a lot of feedback.

 

[lisfan]

hi
yes it is an interference motor. mine failed at 78000 with no noise, just shut off . i replaced my motor with one with 12000. i would replace for the realibilty factor, if it breaks it can damage the valves etc. 50/50 chance in my opinion. hope this helps. some people replace the front chains and guides and leave rear alone, in vehicle repair . you have to pull it to change rear chain

 

[EasyRhino]

I do not have a 4.0, but regardless of the interference issue, if the chains/chain tensioners fail dramatically your engine will be so full of debris that interference or not may not matter.

Additionally, replacing intact chains/tensioners/followers is much cheaper and easier than replacing after it has grenaded.

If you are sure that the noise is the chains, I would replace them.

 

[mattthemechanic]

Yes, it is an interference engine. Worked at Ford for 9 years, replaced tons of these under warranty, and some under recall. Unfortunately yours doesn't qualify because they updated the chains and guides after 97 or 98. They still fail, though generally after accruing more miles than yours has. Honestly the easiest way is to yank the engine and replace all of them, but I doubt you have the timing tools. The kit ONLY costs about 400 bucks! Plus the parts you need. Ah German engineering........