This may be the end of the road - the dreaded rod knock | Ford Explorer Forums - Serious Explorations

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This may be the end of the road - the dreaded rod knock


April 20, 2004
Reaction score
City, State
Cincinnati, OH
Year, Model & Trim Level
1996 XLT
Well gentleman, this may be the beginning of the end for my trusty steed. My 96 OHV has had a gradually increasing knock, both at idle and under load, that seems to be coming from the underside of the engine. It's not super loud yet, but it's definitely become more noticable. Given that it's got 180K on the clock, I'm guessing this is one or more rod bearings. It really sucks, b/c the truck is still in really good shape, no rust (spent most of its life in MS), and runs good otherwise. I had just done the fuel and air filters, and only have a few months on my TT and WS+AAL.

I also have a CEL for P0171 and P0174 (lean condition), which is due to my monkeying with the EGR system to replace the valve, and haven't fixed the air leak yet. I don't think the knock is "detonation knock" related to the lean condition, but I wouldn't bet my savings just yet.

My questions are:

1. What is my next move? Should I check the oil pressure with an external gauge? The idiot light is not giving me any clues.

2. If it is rod knock, how much time/miles do I have before something really bad happens?

3. Are my only two options: 1. get rid of it, 2. pull the engine and rebuild/replace?

BTW, I recorded some quality audio of the noise, but I can't figure out how to attach audio files to a post. If someone wants to take a listen, send me a PM and I'll send you the file.


if the truck is in good shape, and you enjoy driving it, I'd do an engine swap if it was mine, which is what I opted to do when it was found that I had a cracked head in my original engine, cuz the previous owner ran it for a week with a stuck tstat!

I priced a rebuild, vs going the junk yard route with an engine that way - $1200, and still running fine...

The thing though, is mine only had 120K on it, and the newer (to me) engine had like 135, so I cried a little about that, but I got over it, once I felt the power of having all 6 cyl firing all the time, and not smelling antifreeze all the time, etc...

a good friend of mine warned me about doing one end or the other, as the newer end may put more stress on the other - esp a top end rebuilt, etc...

What kind of oil do you use? I noticed that the 4.0 OHV's really like specific oils, and one time I tried to go a little thicker, and she didn't like that... so I run usually 5w 30 conventional - but you might want to go to a thicker oil, might quiet the knock for a while...

with 180K on it, you also have to remember though that the tranny has that many on her too, so that is why I don't think you want to spend the cash on a new engine - sometimes you can get a good price on a reman - but I like places around me that will give a 1 year warranty on a used engine - it was only $300, and the labor was about the same, and then you can always save the heads and sell those of the old engine, etc etc...

my 2 pennies

Thanks, Mediaman. I may actually give this some thought. I've always though that a rebuild is out of the question, I have the tools and skill, but not the space (city rowhouse., park in the alley ). If I could get a quality long block, and get her swapped in a weekend, then it might be doable. Also, forgot to mention that I had the 4R55E rebuilt in 2006. So it's probably got some miles left too. Really the only problems with the truck is this knock, and the driver's side power lock is broken. I'm loyal to the truck, too. My Dad bought it in 1995 as our first new family car in a long time. It's been reliable as hell and served my family well for 15 years. But I'm also trying to be realistic about how much time I can devote to the truck and my need for a reliable vehicle. Just not yet sure what to do. I'll know more after I drive it 280 miles to Nashville next weekend. :)