7.3 IDI Turbo - Knocking - Rough Idle

[Austin86250]

well you probably could rebuild them at home but i haven't seen any rebuild kits and it would probably be a lot more time effective to buy reman injectors
alot of people recommend reman injectors from russ repair here

 

[IDIBRONCO]

I’m also trying to understand how that turbo snail thing comes off. I undid the big bolt on top and figured it spun out of the way but maybe im
Missing something.

You also need to loosen (maybe remove) the two bolts that hold the turbo pedestal to the back of the intake. The pedestal is the thing that the turbo itself bolts to. It also functions as the oil drain from the turbo and the bottom of pedestal goes into the valley pan. Once you loosen/remove those bolts, tilt the whole turbo/pedestal assembly toward the firewall of the truck and you'll be able to get the intake snail/hat off.

 

[94turbocrewcab-lb]

So I’m going to pick up my buddy’s test kit, but I figured I’d update. I dumped a gallon or so of atf in the tank the other day when I changed the fuel filter. I also filled the filter with atf...ran it a bit and let it sit..ran it..let it sit..and it sounds pretty good now. But I found a video of what it sounded like previously.

xc_hide_links_from_guests_guests_error_hide_media

 

[IDIBRONCO]

I'm almost certain that that is not a rod knocking. The knock is too high pitched to be a rod knock.

 

[94turbocrewcab-lb]

Mine sounded worse than that a few days ago and I was certain I messed up the engine..I started it today and it almost sounded normal again. So I’m guessing I might just need injectors and the tune up..could it be that simple?

I realized I thought it was sucking down coolant but I did drain off the overflow bottle the other day.

I might as well just check compression anyways right?

A friend of mine told me to laser the temps at the exhaust manifolds and I’d see one reading a higher temp

 

[IDIBRONCO]

Yes it could be that simple. No guarantees, but it does sound like a BAD injector knock to me. Where you said that it sounds better after the ATF trick was the first clue that it may not be a rod knock. Since you're all ready to do it, go ahead and check the compression. Then you'll know what it looks like.

 

[Selahdoor]

So I’m going to pick up my buddy’s test kit, but I figured I’d update. I dumped a gallon or so of atf in the tank the other day when I changed the fuel filter. I also filled the filter with atf...ran it a bit and let it sit..ran it..let it sit..and it sounds pretty good now. But I found a video of what it sounded like previously.

xc_hide_links_from_guests_guests_error_hide_media

That's almost exactly what mine is sounding like now!

Much louder in person! Kinda scary noise.

This is after I did the atf in the fuel filter trick, then replaced the injectors.

I may go to town tomorrow. If I do, I may run the video on the phone for the startup, and part of the way down the road, Probably just lay it on the dash, looking at the sky, what I want is the sound, anyway.

 

[94turbocrewcab-lb]

Mine wasn’t nearly that bad last week. The truck was sitting for awhile while I drove my sprinters daily. I took the truck after a week or so of sitting. I started it up the night before and it for sure sounded a bit different but maybe I was just getting used to the sprinter diesel noise.

The next morning it was a bit louder coming from the intake..I figured I’d just drive it anyways..I made it maybe 1.25 miles before turning around and flooring it home hoping to make it back. Didn’t make it.

Once it stalled it wouldn’t turn over..like a dead battery and sized engine. I figured I was finished. It started up after I charged the batteries ..not sure why it drained the batteries? But it fired up but was as loud as that truck.

Now it’s just a lot better..but I’m still going to change them out unless I find something wrong with compression.

 

[94turbocrewcab-lb]

I recently found a non turbo motor with 60k miles on it. 7.3 new return lines and glow plugs.. asking price is $800. Given new injectors and injector install kit will run me around $500 and I’m still unsure if that’s the issue. Would it make sense to pick up this motor and just swap that in vs the injectors?

The guy said he did a Cummins swap

 

[IDIBRONCO]

First, it's your truck, time, and money. Spend it how you want to. Second, if it's a running engine that's ready to be put in and started, then it's not a bad idea if you're not convinced that you have an injector knock. Third, even if there's nothing wrong with your current engine except injectors and you end up tearing it apart to find nothing, at the worst, you have a known good extra engine that can sit around for emergencies after you get you Turbo engine back in the truck. That's NEVER a bad thing to have.

 

[94turbocrewcab-lb]

The reason I ask is because I’ve never swapped a motor before. I’ve watched so many knocking IDI videos it’s really hard to know what’s going on with mine when I compare the noises... a few guys thought it was an injector and then replaced the fuel system to find a knocking cylinder.

 

[TNBrett]

Compression test it.

 

[94turbocrewcab-lb]

The motor I found is a 1993 7.3 idi NA...the guy supposedly bought a government auction truck and pulled the motor for a Cummins swap. The engine/truck show 60k miles. Do you think that the gaskets and seals will be ok?

 

[Nero]

I was in a similar situation recently when working on my dad's truck. Had a replacement engine, I resealed the whole engine minus head gaskets and oil cooler. Also spray painted while I had it on a stand, looks great still.

 

[Farmer Rock]

The motor I found is a 1993 7.3 idi NA...the guy supposedly bought a government auction truck and pulled the motor for a Cummins swap. The engine/truck show 60k miles. Do you think that the gaskets and seals will be ok?

Mileage means next to nothing on a fleet truck. It's all in the engine hours, which are usually higher on a fleet truck.


Rock