New rebuild, clogged oil passage!

Mountainman · **Posted:** Fri Dec 13, 2019 5:22 pm

Ok, so this is a continuation of the saga of this rebuild. The electrical starting problem wasn't electrical, Flash had the right idea, but it was a leaky injector, not coolant that had filled a cylinder! Good thing it didnt get going!
Anyhow, the amazing news is that that injector saved my rebuild (or most of it hopefully), as the engine also doesn't have oil making it to the top end! 45 seconds of cranking with no glow plugs and zero oil up top.
-zero oil back down to oil pressure sender, and so of course none to the filter either. Dry as a bone.
After I figured this all out, I remembered that this block had fried all of its bearings which I thought was probably a turbo failure, but it didnt come with a turbo from the junkyard...
So, perhaps the oil passage was already clogged, and the machine shop didnt get the obstruction out when I had them clean the bare block.
My question is, does anyone know where to find a diagram of flow from the oil pump up, so I can figure out how far I need to disassemble to prod around for the clog? I'll probably pull the head and oil pump so I can get the debris washed down into the pan so it doesn't waste some bearings. Of course this is actually why I paid the machine shop handsomely to clean the block...

Mountainman · **Posted:** Fri Dec 13, 2019 7:10 pm

Or the oil pump somehow got wiped out

flash7210 · **Posted:** Fri Dec 13, 2019 7:44 pm

WW will hopefully post a diagram.

It starts with the pickup in the pan.
Then to the pump.
Then the oil cooler on the side of the block.
Then down to the filter.
Then up to the crank and head.

Mountainman · **Posted:** Fri Dec 13, 2019 8:44 pm

Cool, thanks. At least that gives me several places that I can get into with pulling the head or worse. I'll be snaking every passage in the future if possible!

flash7210 · **Posted:** Fri Dec 13, 2019 8:51 pm

I hate to ask this but...

Did you remember to attach the pickup in the pan?

diesel_guy86 · **Posted:** Fri Dec 13, 2019 10:12 pm

I have a diagram, problem is getting the pic posted on here. After the pump is also the pressure relief valve.

Pan->pump->pressure relief valve->cooler->filter->oil gallery. Book says head gasket has built in restrictor, and is also fed oil from both ends of the gallery.

Mountainman · **Posted:** Fri Dec 13, 2019 11:06 pm

flash7210 wrote:

I hate to ask this but...

Did you remember to attach the pickup in the pan?

Definitely worth asking! But luckily I did remember the pickup. I took my time, but may still have done something stupid.

Mountainman · **Posted:** Fri Dec 13, 2019 11:13 pm

diesel_guy86 wrote:

I have a diagram, problem is getting the pic posted on here. After the pump is also the pressure relief valve.

Pan->pump->pressure relief valve->cooler->filter->oil gallery. Book says head gasket has built in restrictor, and is also fed oil from both ends of the gallery.

Thanks! I don't remember checking the relief valve on this one, and they are just press fit, so it might have popped out at the machine shop. You'd understand if you saw the shop I go to, it looks like a bomb went off in there. Seriously trash and everything else everywhere! But, I've only had them resurface heads and clean up this one block. Over a dozen heads with no problems anyhow. Oh, and they have good prices!

Anyhow, I'm guessing the oil cooler is the most likely candidate to get completely plugged?
Could the front cover have a bad seal and cause cavitation, or drawing of air from the top (top of cover above the oil level) and thereby not leak any oil?

Thinking of pulling oil cooler first...

WWDiesel · **Posted:** Sat Dec 14, 2019 1:55 am

I have these on on file:

Mountainman · **Posted:** Sat Dec 14, 2019 6:27 am

Thanks WW!

WWDiesel · **Posted:** Sat Dec 14, 2019 2:36 pm

Remove the factory oil pressure sensor and install a temporary mechanical pressure gauge.
If you have good oil pressure at this location, you have just ruled out the oil pump, the oil pressure relief valve, and the oil cooler.
If you have little or no pressure at this location, your problem is either the oil pump pickup, oil pump, pressure relief valve, or the oil cooler.
I find it kind of hard to believe that the oil cooler could stop up, but on these engines I guess anything is possible.
:POPCORN:

Mountainman · **Posted:** Sat Dec 14, 2019 8:45 pm

WWDiesel wrote:

Remove the factory oil pressure sensor and install a temporary mechanical pressure gauge.
If you have good oil pressure at this location, you have just ruled out the oil pump, the oil pressure relief valve, and the oil cooler.
If you have little or no pressure at this location, your problem is either the oil pump pickup, oil pump, pressure relief valve, or the oil cooler.
I find it kind of hard to believe that the oil cooler could stop up, but on these engines I guess anything is possible.
:POPCORN:

Thanks again, hopefully I'll get to it this coming week.

GordnadoCRD · **Posted:** Thu Dec 19, 2019 7:51 pm

Second one to have this problem. Mountainman, Have you checked out Capt. Dean's thread? There are more oil passages he's had problems with also.

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=3&t=87478&hilit=%2Aclinking%2Aclanking%2A&start=460

Mountainman · **Posted:** Fri Dec 20, 2019 1:02 am

GordnadoCRD wrote:

Second one to have this problem. Mountainman, Have you checked out Capt. Dean's thread? There are more oil passages he's had problems with also.

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=3&t=87478&hilit=%2Aclinking%2Aclanking%2A&start=460

Thanks! I just read that thread, interesting. I'm going to pull the front hex plug on an engine I have on the shop floor hopefully tomorrow and learn some more before I decide what to pull. There's definitely zero pressure passing to the filter. Complete blockage seems unlikely, so it's probably the pump, and I'm not looking forward to my first in vehicle front seal!

Mountainman · **Posted:** Fri Dec 20, 2019 12:39 pm

https://www.enginebuildermag.com/2017/0 ... oposition/

Good read. Worrisome that this article talks about hundreds of thousands of cycles on the overpressure valve, as you have to at least lift the engine to access the pan/valve. I assumed that our engine only uses this valve when there's a problem, but this article seems to dispute that. Hopefully I can get a scope from the oil pump to the over pressure spring to at least see if it is broken. The learning never ends on this platform!

layback40 · **Posted:** Fri Dec 20, 2019 5:16 pm

Mountainman wrote:

https://www.enginebuildermag.com/2017/06/risk-vs-reward-comes-oil-pumps-knowing-whether-reuse-rebuild-replace-can-high-pressure-proposition/

Good read. Worrisome that this article talks about hundreds of thousands of cycles on the overpressure valve, as you have to at least lift the engine to access the pan/valve. I assumed that our engine only uses this valve when there's a problem, but this article seems to dispute that. Hopefully I can get a scope from the oil pump to the over pressure spring to at least see if it is broken. The learning never ends on this platform!

You will probably find the over pressure valve opens when ever a cold engine starts to prevent over pressure killing bearings & making the filter seal leak. Without it, a cold engine can see over 100 psi oil pressure.

Mountainman · **Posted:** Fri Dec 20, 2019 10:26 pm

That makes sense. Also makes sense that the spring is broken as this block had smoked bearings, all of the bearings :banghead:

I figured it was a turbo blow out...

senatorjohn · **Posted:** Sun Dec 22, 2019 6:10 am

Pan can be removed if you drop the front crossmember and I think the front drive shaft. A bit of a hang up with the steering rack but in my case, I was able to leave it connected.

Diesel Dan · **Posted:** Mon Dec 23, 2019 3:37 pm

The oil pressure relief valve is more for protecting the oil filter, galley plugs and gaskets, IMO. While the can of the filter has higher burst pressure than 100psi you can have media collapse with too much pressure differential.
Since the oil pump is direct drive off the crank it can handle the load unlike SBC/BBC. On other engines the oil pump is driven through the timing chain, oil pump drive etc and excessive pressure causes excessive wear.

These threads are why I add some ATF to the oil and run at high idle for a few minutes before draining.

Mountainman · **Posted:** Mon Dec 23, 2019 5:31 pm

senatorjohn wrote:

Pan can be removed if you drop the front crossmember and I think the front drive shaft. A bit of a hang up with the steering rack but in my case, I was able to leave it connected.

You mean k-frame vs front crossmember?

New rebuild, clogged oil passage!

Who is online