Alec

TC, about that oil pump . . .

From the '91.5 and later service manuals:

"The 1991 1/2 oil pump can be used on earlier model engines. However, earlier oil pumps can not be used on 1991 1/2 [all intercooled] engines."

My understanding is that the earlier pump is a lower volume pump, and the IC engines have larger piston cooling nozzles, thus requiring a higher volume pump.

bigragu

Alec- good catch!

thrashingcows

I could tell by the size of the gearing that the pump might not turn as fast....but had no idea about the piston cooling nozzles....guess I know what I have to do today then!

Thank you for the info....would never have known that.

thrashingcows

I had noticed the difference in the main oil pump gear size on the 89 pump (larger) compared to the smaller one on the 93 pump. Smaller would mean it turns faster, and would therefore generate more oil pressure....this makes sense now after Alec's information.

So today was tear things apart again and put the 93 oil pump back in. Pretty straight forward, but did have to put a new crank seal in since I somehow fish mouthed the other one....dang those things are not cheap, at least up here in Canada.

Only other issue is I seem to have now after pulling the IP is an air leak up top somewhere, the fuel is bleeding back over night and the truck during first fire up is missing and blowing lots of white smoke out the back. Clears up after a few minutes, and is fine the rest of the day. I removed the lines from the injectors, cleaned the seats and bores as best I could and re-assembled.....see what happens tomorrow.

Dieselbuilder

Your oil pump issue peaked my interest so i look around and found out the newer pumps are universal the newer ones will put out more volume than older ones the need for more flow on newer engines { just for 89 to 02 .......03 and up are different again }

thrashingcows

Well I still have the/a noise, though the tone has changed, and the RPM at which it seems to start up is very erratic now.

I can be driving up the long hill to the area I live in, 3rd gear the whole way up, doing about 55km/h and spinning about 1900rpm and the noise will come in like a series of waves, get loud then quiet and then fade off to then come back super loud for a few seconds etc.

I plan on swapping in a known decent set of used injectors and see what happens. if that does not change things then I will re-seal my spare IP and toss that in. After that I have exhausted most of the potential culprits, only other thing I have come across in my reading is the pivots on the rocker stands....might try swapping them off my spare head. If still noisy I may have to admit that it could be a wrist pin....

Dieselbuilder

Record it and post it just make sure its a least 4 to 5 min

Blue Goose

could it be something besides the engine TC? trans?

thrashingcows

Not quite sure if you're being serious or not....

the noise never changes if I engage the clutch, or coast in neutral. But have wondered about the clutch and flywheel. worse case scenario would be to pull the trans and transfer case, and fire the motor up....if it still makes the noise then it has to be motor related.....man that job would suck!

bigragu

Yeah it would. You have a transmission Jack? If you lived next door I'd loan you mine. Bought the best one Harbor Freight had at the time, back in 2012. One of the best tool investments I have made. Inexpensive really, if you think about all that weight and chancing that transfer case fall on top of your chest like it did one member here.

The topside creeper would be the second best automotive tool investments I've made. Saw all the mechanics using one at a local hop up diesel performance shop in Sacramento, and told myself I had to have one. At the time I bought it, they were $125 at Northerntool. Man those things have gone up in price over the last couple of years

mknittle

I made a fixture that bolted to my jeep transfer case to make it fit the transmission jack. It made it a much easier job. I will do the same for the truck too.
I suppose it could double as a rebuild stand if built right.

bigragu

That's genius, Mark what the heck made you think of that one? So, I could do the same and bolt on a two ton Jack under my axle, so anytime I needed to lift the truck it'd be right there handy dandy, LOL. Just kidding. Really, though, that's pretty cool. I bet it doubled as a type of "rock shield" I'm guessing?

mknittle

NO, A paper weight, Along with the one that fits hnder the front of a Cummins oil pan and my miniature sheet metal brake that fits in a 20 ton press.

thrashingcows

Once back home from kayaking with my daughter, I decided to quiet up my rattly muffler. It's a 4" straight through unit and I have 4-3 adapters on either end so I could use it on my OEM 3" exhaust. The adapters have been held in with screws, then rivets and now larger self tapping screws.....each time I do this they eventually work loose.

While I had the muffler and tailpipe off I cleaned them up, knocked off the scaly rust, sanded and SOS padded them, then gave the muffler a new coat of paint, and the tailpipe was starting to get a little too rusty so I ended up painting it as well to maybe get another year or two out of it.....Hey it's an old replacement unit and I have been using it for over 7 years now, and it was old when I got it.

thrashingcows

Then I decided I would tear apart, clean and inspect the spare set of injectors Dan (dan123dbl) sent me to try in my motor to see if the noise changes, or goes away with a known set of decent OEM injectors.

Only problem was one of the injectors had stripped threads on the return line port. But I had my old 9mm injectors so I took one and pulled it apart. After looking at everything carefully, and checking and measuring things it appears that the main bodies are the same....Sweet! Only thing I could find different was right at the inlet on the injector, the 9mm has an open port, the 7mm has what is called a edge filter.



Tore them all down, cleaned everything, made sure the tips were not blocked and then re-assembled using 2 cycle oil for lubrication.