So a while back, I bought a spare 7.3 Van engine cuz my 6.9 was pretty tired. It was a pretty decent find and it had some problem "whistling" or making some odd noise. The PO took his van to a shop and they ripped out the engine, noticed one of pistons was delayed, and wanted to charge him a LOT to fix it. The PO sold it to me rather than pay to fix the beast.

So I got this engine a few months ago, and I just today got to rip it apart finally. The 8th piston was clunking when I turned the flywheel by hand. I figured the connecting rod or bearing or crank was messed up. I wouldnt' be able to tell until I got the oil pan off.

Here's what it looks like with the oil pan off and my wiggling the flywheel:


I definitely found the problem. I'm thinking the bearing is busted to hell, but anyone else have any ideas. I'm going to pull the connecting rod bolts out and see if that'll give me anymore information.

This is the first time I've fiddled around with the bottom half of my IDI's. Any advice while i'm working on this?

Also, I'm thinking while I have it apart, I'll replace the oil pump. I don't know if this one is bad, but I'd hate to have to pull the engine again to replace it if this one is on its last leg. Any suggestions on where to buy a decent oil pump?

 

Looks like the rod bearing to the left has a lot of clearance, probably spun. Your video is pretty short but I believe the noise/ movement is on the one to the left.

If the crank jurnal is bad it might be able to be turned. I tried that once with no luck. I also tried smoothing the journal with several grades of sand paper and cloth to a different engine. Apparently that worked fine for the customer. I let the truck idle for a couple hours after startup. You should also check the rod and cap for distortion if the movement/ noise is coming from there.

 

you could also have a broken crank. i have seen them snapped on an angle under the rods. it will still spin both halves but makes a nasty racket just like what you have.

 

Pull it apart, and inspect the crank. Have the crank turned at a machine shop, that journal at least, get undersize bearings for those rods. A machine shop can measure and let you know exactly what it needs. If it was run long like that the crank could be trash, but they are out there. I was sitting on a perfectly good std/std crank for a year and gave it away along with a bunch of other parts to a guy who needed a block. Probably got scrapped.

In any event, go through the entire oiling system. Low oil pressure is a likely cause of failure of rod bearings. Check that all the piston cooling jets are installed, the earlier engines were press fit and could (though rare) fall out, resulting in a significant drop in oil pressure. Could be some crud accumulated in the crank oil passages between that rod journal and the adjacent main journal, restricting oil to that rod. Loss of pressure due to some other "leak" such as loose turbo bearings and no restrictor to the turbo feed, stuck relief valve in the filter/cooler header, etc. Check all these.

Also I've heard the aftermarket oil pumps are not as good as original. Not sure why or in what way or if it's true, but disassemble and inspect your oil pump. Check the rotor and housing for wear and damage, measure rotor clearance with feeler gauges to evaluate wear and suitability for continued use.

This is a good time to consider any bottom end upgrades like the R&D modified PSD rods, main girdle, pistons, etc.

 

I'm trying to not go down that rabbit hole. It'd be nice, but really, I'm just looking to get this back to running order so I can have my 6.9 swapped out by March. If I dive into this with a bunch of R&D parts, I'm probably going to be working on this for months.



Is there a way to pull this apart and replace the bearing without turning the crank (assuming the crank is not damaged)? If I inspect the crank and see no significant wear or issues, and measure it with a caliper, what would be the minimum tolerance for making this work?

I'm probably just getting ahead of myself, but I'll rip the rod apart this morning and post some pics of what I find.

 

I was shopping around for IDI oil pumps. After reading a few threads about this, seems like a few FTE veterans don't like Melling. Anyone have a preference?

SEALED POWER 22441999

ENGINETECH EP165

MELLING M165

A fourth option is to pull the oil pump off my other 7.3 in the garage. I don't know if it's a stock pump, but would reusing a stock pump with 200K better than a new aftermarket pump?

 

That crank journal is trashed. Do it right and do it once, or do it as many times as you want if you want to cut corners. Either way, pull the rod cap and have a look. Measure the journal. Inspect the rod big end. That journal is no good if the rod big end is flapping around as much as it seems to be in the video.

I don't know the factory spec but acceptable rod bearing clearance will likely be in the .001"-.0025" range. If you don't have mics you can plastigauge.

Either get a new pump or check the condition of yours. We can't tell you what condition a pump sitting in front of you is in, at least not without pictures and measurements. I can't recommend a manufacturer for this application, but I've always used Melling pumps on gas engines and don't recall any glaring QC issues.

 

It's a lot worse than I expected. There is noticeable difference between the thrashed side versus the smooth side.

I'm considering pulling the crank from my other 7.3 and swapping it over. Then I can do the bearings right. Plus I'm probably going to need to bring over a rod and rod cap from the donor engine, since the offending rod and cap is thrashed up as well.

Then, if I want, I can have the crank turned on my own time and have a backup, assuming it's still within spec.

Here are some pics:





Offending rod cap:




Remaining bearing:




Clear radii difference on the crank (without even needing to use a micrometer):

 

that crank is scrap. i doubt you will even be able to buy bearings to make up the difference once it is turned true.

 

My donor 7.3 is from a 1988 van. My new engine was from a 1994 uhaul van. Can i move the 1988 crank to the 1994 engine without issues? I'd assume yes, but I thought I would ask regardless just in case there was some difference.

 

As long as the 94 wasn't a turbo motor go for it, the cranks should be the same either way, but you may run into different balancing issues. I think a used crank, New rod/main bearings and a set of total seal rings from r&d would go a long way and easily give you another 200-300k if the heads aren't shot.

If you have the heads rebuild, have new guides installed but leave the oil shields out, the 7.3 style which they also give you for a 6.9 let the valves get too dry and they wear the guides out too quick, a original 6.9 would let them sip a little oil, but in return the valve train would last forever, my 6.9 got new head gaskets at 450k and all the valves and guides specd within normal range so I didn't even bother..

 

Wow ive never seen one that bad that didnt throw the rod. Tough old pigs these things. Gen, i too remember reading the "old crew" on here when i joined didnt like aftermarket pumps. Something about all made in china and not worth buying. They said to check the stock one and run it. To be very frank about it, i was always curious, but when i built my new engine, i did in fact reuse the original oil pump. Im guessing the one in the engine with the spun bearing is probably questionable.

 

I've heard that many times on other automobile forums as well. People are quite leery of the Chineseium pumps.
If this pump were to be reused it would definitely need disassembly, cleaning, and inspection as it's likely it has plenty of metal shavings in it. It has the suck the oil up before it gets to the filter.
Maybe just pull a used pump from another engine?

 

The heads I'm going to put on it are the ones I bought last year. They were completely dressed and pretty nice. Here's the write-up I did on them: 1988 E250 Van 7.3 IDI Head Gasket Job (without pulling the engine) ? IDI Online

Ideally, with transfering the crank and heads (and getting new crank seals and bearings), I'm hoping I can finally build a decent engine out of all the parts I already have. I was re-reading the Ford Service Manual to get an idea on the process, and considering I have a 20-ton press for the seals, and have all the pertinent tools and parts, I'm thinking I should be ok. I'm still not entirely sure on the process for measuring for bearing size, but I'll get to that once I pull the used crank from my spare 7.3.

I'm considering transfering the oil pump from my spare engine as well. I don't want to reuse the oil pump that allowed this bearing to fail.

Overall, the underside of this beast isn't as intimidating as I expected. Pretty logical, and with my engine turned 90 degrees on my stand, it's pretty easy to work on compared to the contortionism that I have to typically do when I work on the engine bay of my van.

 

Quick semi-related question: When I bought my heads, the shop that worked out the transport for me asked me for my VIN. They said that some IDI heads were slightly different. Is that true? Should I have to verify that the heads I have for my 1988 IDI 7.3 are compatible for my 1994 IDI 7.3? Or should they bolt up no prob?