4.6L V8 Oil Pan Removal/Rod Bearing Help needed

[matelec]

Gidday from Australia,.
I have a 4.6L XLT V8 purchased new 2002. The engine has just developed a rattle around 1500 to 2000 rpm that sounds like big end/rod bearing starting to go (confirmed by four different mechanics). Its only just started so I am hoping & praying I can get the sump pan off, inspect & maybe replace the effected bearing shells - without removing the engine!!! Its travelled 55,000miles, always been serviced at the same ford dealership. Any advice would be greatly appreciated. Anybody else out there had similar trouble?

 

[E.B. Cornburner]

There have been lots of threads here regarding noise in the 4.6L engine. Few, if any, have been pinpointed to be rod bearings though. Most have timing chain/tensioner noises. The 4.6L Modular V8 engines have been pretty decent as far as the bottom ends go. I don't see any come in to my shop with anything but minor issues. Only exception is when someone completely neglects one, not changing oil for tens of thousands of miles. We've only replaced one 4.6 in the last probably 5 or more years, and that was due to blatant neglect on the previous owner's part.

To answer your question...I don't think the oil pan comes off real easily without removing the engine from the frame. I seem to recall quite a few obstructions that would prevent its easy removal.

 

[matelec]

Appreciate the feedback EB . I have scanned through most of the forum's & read heaps of posts regarding engine noises. This noise is definitely louder at the bottom of the engine & dissappears when spark or fuel is disconneted from #8. Your right though, I cannot find anyone who has had a bottom end bearing issue with this motor. As I say, vehicle has always been maintained by Ford, has had all its scheduled services on or before time and is driven (by my wife ) around 5-6miles per day dropping kids at school - doesnt make sense I know. Any other feedback would be greatly appreciated.

 

[E.B. Cornburner]

If the noise is only on one cylinder, I'd be leaning more toward a piston issue than a rod bearing. I've seen engines that sound and behave exactly as you described, and usually a part of the piston is broke where the wrist pin fits to it.
Typically, if it's a bearing, it wouldn't just be one...There'd be wear on all of the rods and main bearings. If one goes bad, all that metal can get thru into the others. Dropping the oil and looking for metallic shiny-ness in it is a good indication that it's a bottom end problem and not a piston or similar.

Either way, the engine would have to be removed and torn down to fix it.

Personally, I'd find a nice used engine in a salvage yard, and drop it in all complete. Most the time this is the path of least resistance compared to tearing your engine down and repairing the failed part(s). It doesn't always answer the question "why did it fail in the first place?", and doesn't guarantee a future failure. Also, by the time labor is all factored in, you're usually money ahead just changing the entire engine assembly whole.