I have a 2000 F250SD PU with 60K mi and have a nasty knock that sounds "Deep" in the engine. Runs "Great" under normal conditions at all speeds when RPMs lower than 2300. If, you are running at freeway speeds, say 60-65 MPH on the flat open road all is well! as long as you have your foot on the gas. If you let up slightly, you start to hear the knock. Also, if you sitting still in park and run the R's up past 2300, the knock shows up. I was thinking Rod bearings but now someone tells me it could be the torque convertor or a cracked flywheel. Any thoughts?

 

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similar problem here Bill. If you've figured it out let us know. I have a 99 E 250 that has a loud/hard knock under any accelaration/throttle increase that quickly goes down to a light "patter" at idle (like an OHC tappet sound). It had a tranny put in when I bought it (last week) and was hoping it was TC but all nuts were tight on the plate. I too had someone tell me it could be the flex-plate but before I split the tranny/engine I'd like to get some direction. To me it would be easier to raise the engine a few inches to clear a oil pump and pull the pan to look at the crank/rod bearings than split that monster...Ideas/directions anyone?

Bill in Denver
Rmvr53@aol.com

 

My EFI 302 used to knock only under a load. It turned out to be wrist pins. The guy who rebuilt my engine said that under load knocking is usually a wrist pin. Not sure why.

 

knock knock...guess whos not there....

finally had a chance to drop the pan on my 99 E250 5.4. Guess what I found ...#4 rod bearings wern't there!!! Amazingly tho, the journal was in pretty good shape. Gonna polish it up this week and see what my final outcome on specs is but currently looks like I can go back stock on #8 and #4 is dead on 10k under.

Bill

 

Better check those rod bearings Bill, before you end up with a rod out the side of the block or a totally trashed crank.

 

already set to replace the rest of the set Jimmy...in there only once I hope...and thinkin about doin the mains as well. Did a "save" like this in an 60 T Bird I had 30 years ago. Polished a scarred journal to .005 over and drove it for another 75k miles before I sold it in 1985.

Bill F

 

Well..Im screwed..

polishing went great, came out at 11 under so put a 10 under in #4 and put it back together. Ran around the shop/area for 3 days no problems. Drove it home (30 miles) and by the time I got there, I had a nice sweet ROD KNOCK again!!. The oil pressure gauge says I've got good pressure but Im beginning to doubt the accuracy of the dash gauge. Anyone else ever had an oil pump go on these engines - which subsequantly takes out #4/8 bearing due to last on the oil feed?

Bill

 

Well, the factory gauge is a dummy gauge, If it has over about 7psi, the light will go out and the gauge will go about 1/2 up. You can have a rod knocking and still have good pressure, most of the pressure is made by the main bearings.
So you may try hooking up a mechanical gauge to see what kind of pressure that you really have.

 

where is a good place to hook one up?

Bill