1986 E6 350 Low oil pressure after rebuild

[Vladislav]

15 hours ago, Mike Schilderink said:

I have a full service manual for my engine.

I was trying to say that I do not get any oil flow out of the cam bearings. I do get good flow to the rods.

The oil flows from the oil rifle to the main bearings. Then according to the oil flow diagram (illustration A or #16&#17) the oil feed for the cam bearings comes from the main bearings.

I was wondering how that oil is transferred across the upper main. 
 

I almost think that the upper main needs to look like a rod bearing with two oil holes. One for the inlet from oil rifle, and one for the outlet to cam.

My original bearings are at the bottom of my scrap tote, but I’m pretty sure they matched the replacements. I think I better dig them up.

It's a very good point to investigate. I could look at E6-350 block since I currently have one apart in my shop. But I can do it tomorrow.

[Mike Schilderink]

@Vladislav  Thank you, that would be great.

I talked with an older service manager at Bruckners Amarillo. He told me that the upper main that I posted pictures of was the correct one. He also told me that the main bearings are very particular on how they are installed to line up the oil passages.

I think I will just pull the mains, inspect, and replace with the Mahle set that I got.

[Vmac3]

I don't want to come across as being an ass, but how much time has been put into diagnosing this oil pressure issue? To me it sounds like you have an oil passage as being restricted. There may be some junk that is blocking the oil galleries or the main bearings are the wrong ones, causing all this grief. With all the information we have so far, 

Rods and mains are within spec.

Oil cooler is not blocked.

No leakage from cam bushings????

Oil pump okay.

Oil is at the proper level.

This leads me to a restriction somewhere. You may want to recheck the parts you put into this engine.

V

[Rob]

I've not been following the thread but you do have the original engine in the chassis and it is a 4 valve head correct? As Joey said there are several variants of cam, and main bearings used over the years and I always ensured the block casting numbers corresponded to the ordered parts. On more than one occasion I'd received the incorrect main bearing set, and same with the cam bearing set.

Hoping you don't have a big "blob" of RTV residing in an internal passage someplace as I don't get the impression you were very impressed with your terminated mechanic's abilities.

[Vladislav]

I got to my E6 block today. It layed on a pair of wooden beams so a truble to look over its bottom side. The pic is what was seen from the flywheel end. So those are #7 and #6 main bearing seats. As you can see there's a passage for oil bored so oil travels behind the bearing shells. I remembered you had the issue with cam oil supply and the passages were organized through #2 and #5 mains. I couldn't easily see those seats but I put my hand there and touched #5 surface by fingers. It also had that same kind of oli channel as you can see in the #7 on my pic.

[Mike Schilderink]

Called Mack and they said my truck was born with an E6 285 2v.

I ordered my in-frame kit off of the truck’s vin, so I called PAI and they said that my vin showed that I had an E6 350 4v, and that is the kit they sold me. (I have an E6 350 4v.)

I ordered new rods and mains off of my engine serial from Mack.

I think I had no oil to cams due to lack of flow from test tank/and or the majority of the oil coming out of the mains. (I’m pretty sure my problem is caused by the main bearings at this point.)

A restriction blocking oil flow to the cam is very unlikely considering each cam bearing is supplied by its corresponding main bearing (not supplied by 2&5 mains).

I attached pictures of my upper mains. You are able to see that the oil passages in the block line up with the bearing’s hole. #4 upper is the only one that is different, but it looks like it has a small loop that reaches that oil hole. I made sure all the bearing oil holes (including 4) lined up with holes in the crank. 
I am just going to replace rods and mains, plasti-gauge each one, and check oil flow again with my tank. 

[eshack93]

Mike, Did you ever figure out your problem on this? I just did a rebuild on 2 valve e6 that has the exact same symptoms as yours. Oil pressure is great on startup but just drove it 10 miles and at an idle it’s already down to 15 psi and 60 psi at 2,000 rpm. Wondering what my issue is. 

[Joey Mack]

Did you replace or inspect the oil pump? There is also a pressure valve in the oil filter housing, is it good?  jojo

Edited May 9, 2022 by Joey Mack
More content needed

[eshack93]

Joey I read through this post and went through a lot of the trouble shooting Mike did. I have checked the pressure valve on the oil filter housing and did not see an issue with it at all. The spring had a lot of pressure on it. Cleaned it put it back together. I changed the crankshaft when I did my inframe so the oil pump was off, the rebuild kit came with some o-rings and gaskets for the oil pump so I changed them. What are the odds something didn’t go back together correctly on that pump? I mean it was relatively simple just a couple bolts. But I definitely do not have the correct oil pressure now 

Edited May 9, 2022 by eshack93

[Joey Mack]

got it..  to be honest, I I have only been in a handfull of E-6's..  so I can't think of something else to check, outside of something not installed correctly, however, I do not like to question a Mechanics ability without more info..  There are a bunch of guys here that know way more than I will probably ever know.  The best I could do is go get my book and read it to see if there is another check that can be done.. With respect, jojo

[eshack93]

Yeah I get that. I’ve worked on a lot of stuff but this trucks been a headache since day one. I was hoping the inframe would solve a lot of that. I tightened up a lot of oil leaks, air compressor, power steering, remachined heads, new valves, pistons, liners, all bearings, crank, clutch, radiator. Only thing I didn’t change was cam and oil pump. But yet I’ve got low oil pressure and I’m banging my head against the wall. Only thing I can think is that oil pump was on its way out. That pump is not timed is it? It’s driven off the air compressor gear which was not timed. 

[Joey Mack]

did you inspect the oil pressure relief valve in the oil filter stand, where it mounts to the block?  the valve can not have any hard scratches on it and the bore needs to be Round.        The oil pump relief spring test is 40 lbs. +/- 4 lbs. at 3 5/64"..  this is for all but the bypass filter type.  that one is.. 25lbs. +/- 2 3/4"..   jojo

[Joey Mack]

no timing..  I have a 2 valve in my shop that i pick at from time to time.  in the oil pump....  with the cover off, put a straight edge over the gears and housing..  A .007" feeler gauge should be hard to insert under the straight edge...  if its loose,,, get new gears..   the clearence of the pump gears to the inside of the side walls of the  housing is .006"  these are the 'high limits'  the low limits are .001 and .002"  respectively...  I hope i'm helping... jojo

Edited May 9, 2022 by Joey Mack
More content needed

[theakerstwo]

When you plastic gauge the mains make sure and jack the crank up with  jack to get the dead weight off or the brgs.

[Joey Mack]

So here is one guy I was hoping would post...  He doesnt have to open a book, he just know's..  (Glenn)....    jojo

[eshack93]

Yessir I made sure to jack the crank up and did one bearing at a time. It’s all within spec. That’s why I’m Kindof having a mind explosion. I’ll check on that oil pump and get back with you. Maybe when I changed a gasket something fell out of place. Thanks!

[Joey Mack]

the side measurement is to check the housing for wear...  simply put...  if its worn, just get a reman pump..  jojo

Edited May 10, 2022 by Joey Mack

[63BMack]

Did you have the filter stand off??. If so did you get the right gasket between the stand and block, there are different gaskets.

[mowerman]

I see this is an old post but I did a rebuild one time used a chunk of wood to punch out the pistons and then a little sliver of wood got stuck in the high pressure relief valve it wasn’t closing off just another helping hand that’s probably not what it was I was even surprised that I spotted it … bob

[eshack93]

I did the oil filter stand off but that was probably 10,000 miles before the rebuild. Didn’t have any oil pressure problems at the time but the number two rod bearing spun. Which caused the rebuild. Ordered the gasket for that oil filter stand off the vin and it only appeared to fit one way. What are the odds those two things are related? 

[mowerman]

I wasn’t aware you were still messing with it… good luck partner 

[eshack93]

Just looked through my service records. I replaced oil stand gasket approx 1000 miles before overhaul happened. Didn’t notice a drop in oil pressure after that gasket was replaced though. Coincidence? Or do you think they’re related?

[fjh]

15 minutes ago, eshack93 said:

Just looked through my service records. I replaced oil stand gasket approx 1000 miles before overhaul happened. Didn’t notice a drop in oil pressure after that gasket was replaced though. Coincidence? Or do you think they’re related?

I would be inclined to investigate the pedestal relief valve and or the oil pump relief valve! Also check to make sure your oil level is not over full! Also make sure the oil pickup is sealed on the pump! (Not sucking air) 

A kind of related incident that happened to me!

I was once tasked to I check on why a guys engine brake was  working intermittently  ! I removed the valve covers did all the necessary checks and sets there checked out the electrics all seemed good except the oil pressure was a bit off!  ! So i decided to check is oil pump ! WEL I put a Drain pan under the truck and pulled the drain plug AND low and behold only two gallons of oil existed in the pan! I was fairly pissed at my self for not checking at the begining  but you would think a guy would check his own oil level one a day! Guess not!

JUST SAYIN! 

Edited May 10, 2022 by fjh

[eshack93]

Well I double checked the gasket at that base of the filter housing and it’s definitely got the correct gasket. I was sorta hoping that was the problem. Gonna drop the pan again and double check the oil pump. Make sure nothings missing or out of whack on that. However I did notice when I pulled my oil filters off that they were only about 3/4 full. What would cause that? 

[eshack93]

Would the surface rust on this pressure valve on the oil pump itself be a problem? I also pulled some bearing particles out of those small holes. I’m not super confident in my knowledge of how this oil pump works and what this pressure valve thing is for