Jump to content

1986 E6 350 Low oil pressure after rebuild

Recommended Posts

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.

Никогда не бывает слишком много грузовиков! leversole 11.2012

Link to comment
Share on other sites

@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.

Link to comment
Share on other sites

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.


Link to comment
Share on other sites

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.

Dog.jpg.487f03da076af0150d2376dbd16843ed.jpgPlodding along with no job nor practical application for my existence, but still trying to fix what's broke.



Link to comment
Share on other sites

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.


Никогда не бывает слишком много грузовиков! leversole 11.2012

Link to comment
Share on other sites

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. 



  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...