"Wrist Pin Knock" questions.....parts motor with new IP

[Thefarmboy21]

My truck needs a new IP and injectors and it just so happened that my neighbor had a whole motor taking up space in his garage. It's a 92 model 7.3 N/A motor. It's got "NEW" but 3 years old, injectors and injector pump from Pensacola Diesel. NOW here's the strange part......
He had the IP and injectors installed, drove it to work and it sounded like it was ticking. Loosened lines and isolated the number one cylinder. Put another new injector in it and same thing. He said he didn't notice the knock before the new parts. So he opted for a whole new motor. I bought the whole shebang for $375. My question is: do you think it's a wrist pin or could it be the pump? Either way I think I got my money's worth. It's got the wiring harness, new glow plugs, new clutch, new IP and new injectors. New parts were installed by a professional diesel mechanic and have about 25 miles on them give or take. They've just been sitting in a garage.

 

[Hydro-idi]

Probably the junk Pensacola IP and injectors that are causing the engine to knock. I would look at those items before tearing into it.

 

[icanfixall]

Same thoughts here. Pensacola gave them selves the reputation they have now... Nobody gave it to them. Sadly some get bad parts from them. I used one of their pumps till it began to leak fuel out the pump shaft seal on the drivers side at the bottom. I may have been able to fix it but I had a "spare Moose pump" too. So I installed said moose. I think many members here feel the pensacola parts are bed ******** and not much more...

 

[jaluhn83]

Hard to tell with the motor out - But it does sound more fuel related to me. I've got what I'm pretty sure is a wrist pin knock on my truck and it's been there for thousands of miles and gradually developed. It's also very prominent from underneath the engine - not at all like a fuel knock from that angle.

 

[RLDSL]

Sure sounds fuel related. id if pensacola has had their hands in any of the parts, all bets are off as far as functionality of whats in there. A diesel fuel knock sounds EXACTLY like a gasser that is about to throw a rod., but that little man with a hammer on a diesel is rarely mechanical in nature.

 

[Thefarmboy21]

Ok thanks guys. So what causes the fuel knock if nothing's really loose? At least I know if I put the IP in my truck and it has the same noise in same cylinder that the pump is bad and the 7.3 is more than likely good lol.

 

[icanfixall]

The diesel fuel knock talked about here is fuel being injected into the precups way too early. Thus, we hear the knock of the fuel igniting early... Really kinda simple in theory. But horible to do mechanically to an engine..

 

[79jasper]

I would pull the pan and look inside.
I say that from personal experience. Had a engine sounding exactly like that. Loosen the injector, sound would go away. Well it turns out, cylinder #5 had a busted piston skirt, and the broken piece was laying in the pan.

 

[riotwarrior]

I would pull the pan and look inside.
I say that from personal experience. Had a engine sounding exactly like that. Loosen the injector, sound would go away. Well it turns out, cylinder #5 had a busted piston skirt, and the broken piece was laying in the pan.

You have a very valid point, seeing as the "Spare" engine is not in a vehicle that's a great idea and well worth inspecting.

If you have the ability to do this, I concur with the above, for the cost of a bit of brake clean and some decent silicone to reseal the pan, why not take a peekaboo!

Al

 

[Knuckledragger]

X3 on pulling the pan. It is far more likely you would hear a rod knock before a wrist pin knock. The wrist pins are full floaters held in s bushing and even fully worn out, they hardly move at all. I am voting for a fuel related problem, or maybe low oil. There are plenty of things on these engines that can make knocking or ticking sounds that are more annoying than destructive.

 

[Thefarmboy21]

Thanks guys, I'll try to bust it open. I really don't care what's wrong with the motor, I've got it sold anyway. I just wanted to mainly know if it could be the pump and why the fuel causes that sound. I'll probably just switch it over and see what happens. My IP is shot and the truck won't start anyway. Plus I've got some bad injectors so I've gotta swap them out anyway.

 

[icanfixall]

I'd like to add something about busting open the engine.. When you remove the pan do not use a cork or rubber gasket when installing it. Just because you find a pan gasket in your gasket set does not mean you use it... there are plenty of gaskets in a set that are not used because the sets applications cover many engines. International never used a oil pan gasket.. What worked for them was RTV. Thats what I use and never have found a leak ever using it. I use the permatex ultra plus copper stuff. It high temp and oil resistant. So it has worked well for me for more years than I have had my rig.

 

[jaluhn83]

Depending on your budget might also think about pulling the heads too while it's on the ground. Easy to get the off and check everything out while it's on the ground and then you know you're putting in a good solid rig.

Course even going that far woln't really tell you what the wrist pins and rings look like - only way to do that is pulling the pistons.

Personally, I would go through it and make sure everything is right before you put it in. Then there's no wondering what's wrong if it make a weird noise or something down the road. I've got that problem with my rig now - it's been rattling for years now but I'm hesitant to drive it cause I worry that's it's going to blow up on me one of these days. Not a good feeling. On the other hand, money does factor it - these are not cheap motors to work on.

 

[jaluhn83]

Also, I would use the gasket. Just my $0.02, but I don't like using straight rtv if I don't have to. Gaskets have worked fine for me, you just have to make sure the bolt holes aren't dented in (a ballpeen hammer works well to dish them back out) and not overtighten the bolts. Unless you apply the perfect amount you'll get rtv globs oozing out and then you have nice chunks of the stuff floating around inside the engine potentially clogging things up.

 

[Knuckledragger]

Also, I would use the gasket. Just my $0.02, but I don't like using straight rtv if I don't have to. Gaskets have worked fine for me, you just have to make sure the bolt holes aren't dented in (a ball peen hammer works well to dish them back out) and not over tighten the bolts. Unless you apply the perfect amount you'll get rtv globs oozing out and then you have nice chunks of the stuff floating around inside the engine potentially clogging things up.

Neither Ford nor IH used oil pan gaskets. The engine service manual gives clear, simple instructions how to lay on the RTV silicone, and I am not one to read instructions much. Installing the gasket has caused more reported leaks than prevented them. Do it any way you want. I like fewer parts to mess with.