Just bearings

[gearhead]

my friend just bought a 94 F350 turbodiesel(pre powersmoke) on my advice.The engine was making some noise that I just assumed was normal diesel noise.according the the previous owner the oil pressure and coolant temp gauge don't work.Im thinking the oil gauge is working because that motor has rod knock.I am just wondering if there is a kit for the 7.3L that is just bearings and oil pan gasket.Instead of new rings,and various other gaskets.Truck has good compression so I don't believe it needs new rings,new headgaskets,etc and all the other stuff that normally comes in a rebuild kit..

 

[argve]

The oil pressure gauges in these IDI's are hooked to a switch so I would recommend checking it with an actual gauge before assuming it's working...

 

[Diesel JD]

I agree with what Travis said, also in some cases the spring in the reaar oil cooler header can get buggered up. When that happens the oil pressure gets low and sometimes the check engine light will even come on. If that's your problem the spring needs to be re-shimmed(difficult and not recommended) or the rear header gets replaced as a whole, (more expensive but easier and correct) If it comes down to replacing the bearings it can be done in the truck but from what I hear that's a really difficult bit of surgery where you take loose the engine mounts and jack the engine up. Then unbolt the oilpan and put your hand inside to drop the oil pickup...which is the reason the whole works won't fall off with the engine in frame, with the pickup installed, there isn't room between the frame and the block to drop the oil pan.

 

[Brianedwardss]

Would that knock by chance be advanced timing?

 

[oldmisterbill]

Would that knock by chance be advanced timing?

Or a bad injector? Or a cracked flex plate-Or?

 

[Knuckledragger]

If it is real low on oil, the lifters starve and the rockers make a sound like a rod knock. Don't ask how I know.

 

[Brianedwardss]

If it is real low on oil, the lifters starve and the rockers make a sound like a rod knock. Don't ask how I know.

Don't ask me either

 

[lotzagoodstuff]

+1 on bad injector sounding like a rod knock.

For the typical service life and mileage, you don't see a whole lot of bearing issues with IDIs. I would check oil pressure with a real guage, then start looking at individual injectors. If it was me, I'd even think about putting a new set of injectors in it as the work/time/money is pretty easy in comparison to swapping bearings with the motor in (or out of) the truck.

Just my .02.

 

[gearhead]

unless a failing injector sounds the same as rod knock through a screwdriver to the block than I don't know where checking the injectors will get me.

oh yea I forgot to mention that according the gauge in the truck it has good oil pressure when cold but when its warmed up...

 

[dyoung14]

First- get you a real oilpressure gauge and install it, readins should be no lower than 7psi idleing, now do you see the 8 metal lines snaking all over the top of the egine? see were they connect to the injector? Start the engine up and let it idle, get a 5/8 wrench and loosen each line one at a time if the knock goes away there is the bad injector

 

[Dsl_Dog_Treat]

X3 on bad injector sounding like a rod knock.
What happened with the one I had was diagnosed as I was driving the truck and it started hammering worse the farther I drove it. Limped it home. Checked rockers and lifter travel, all was good. I decided to check the injectors just for giggles since I own a tester. Found one injector that had loosened up but was not showing physical symptoms of such. Pulled it out and found the pintle was seized completely open! Due to the extreme heat of the escaping gases it overheated the tip causing the failure. In full open mode, the injector was dumping fuel in unatomized and since that fuel wasnt burning it was just filling up the cylinder and began to hydrolock the cylinder giving the false diagnosis of a rod knock. I was literally 15 minutes from pulling the motor before that simple check.

 

[RLDSL]

A slobbering injector in a diesel will sound exactly like a rod knock in a gasser. Even if the loosening the lines bit doesn't find the culpret, yank them and have them tested, I bet you find a ******. Hammered bearings are rare in these beasts.

 

[oldmisterbill]

The reason I posted,is because aI had a severe knock develope while I was on the highway.It sounded like a rod knock - (Been working on engines for years) towed it to a truck shop.The owners son (around 40 years old or so) looked did the stethascope thing,shook his head & said "its gonna be an expensive major repair".His father an old school guy probably in his late 60 came in -listened -felt the hard injector lines & said replace that injector! $60 dollars later I was on the road again. Funny I couldn't feel a difference in the line but he did,otherwise he wouldn't have pointed at the guilty injector first try.

 

[THECACKLER]

Rod bearings will be worn if the previous owner simply topped the oil when it was low instead of changing it regularly. I have the worn Rod Bearings to prove it. I think the oil gets diluted with Diesel Fuel to the point that it will not have the viscosity to protect the bearings.
Plan on pulling the the engine and heads to do it right.
Rod Bearings, Intake Gasket and Head Gaskets are available from Northern Auto. Get the Clevite bearings not the Federal Moguls.
There is no Oil Pan Gasket, they use RTV. 1/8" bead on the side rails and 1/4" bead front and rear and around the corners.
Reseal the Oil Cooler while it's out.