Left head won't prime with oil

b4black

Well-Known Member
Joined
May 24, 2001
I purchased a rebuilt 4.1 a few years back and I'm finally ready to fire it up. I pulled the valve covers and I am priming the oil pump with a drill. It's getting oil through the right head and the turbo oil feed, but nothing on the left head. :(

Engine has a new timing cover and a roller cam. What's most likely wrong?

Thanks!
 
The 4.1 block is different than 3.8. There is a mod you can do to supply oil to the other side with a crossover in back of the block

Sent from my iPhone using Tapatalk
 


Sent from my iPhone using Tapatalk
 
If the oil gallery plug behind the timing chain on the passenger side is to deep it will prevent oil from getting to passenger side lifters . I’m not certain on what side it is but I know that if that freeze plug is to deep it can ruin your day you can see in the picture the crossover port
21B64972-87E5-4816-98CB-C7F9E38BF4B0.jpeg
6666DCBC-1FF8-470D-8E3D-0A78A2B3EF52.jpeg
 
Well, the engine was lower mileage and I don't think the freeze plugs were changed. That would leave an issue with the cam bearing. The rebuilder has experience with 4.1, so I'm not sure what happened.

If it is an issue with the cam bearing, will adding the crossover at the back be good enough? (That's seems like the easy solution)
 
The issue is the roller cam doesn’t have the oil groove in it like the original cam did and normally the simplest solution is the rear oil crossover. You could get different cam bearing that are grooved from TA performance or groove the block but normally people don’t want to pull the cam back out. There are plenty of threads that list the proper size fittings for the crossover on the rear of the block.


Sent from my iPhone using Tapatalk
 
Non grooved block with a non grooved cam (roller) and you've got no oil on the DS lifter rail. If someone tapped the front lifter galleys for pipe plugs, you can choke off the DS by going to deep (giggidy).


The best answer is to pull the front cam bearing and groove the block. (that's assUming the reason isn't improper installation of the pipe plug)


A 'fix' is to build a connection on the rear cam journals. The main issue with that is getting it right, and hoping it doesn't crack in the future. Once the engine's in, getting to that area is a real bitch.
 
^^what Earl said. Additionally, you create 2 more potential sources for leaks.
Fix it right.
A. Cam brg.
B. groove the cam. Either way, the ft of the engine has to come off, and the cam out.
While the cover is off, do Earls cover/oil pump mods.
 
Well, the engine was lower mileage and I don't think the freeze plugs were changed.


Two problems with that statement. First, 'low mileage' is not a good thing when it comes to rebuilt Buick V6s. Every fresh rebuild I look at is a POS until it has a chance to prove itself. They either have problems right off the bat (like yours), or they last forever.

Second, if someone rebuilt your engine and didn't clean out the oil galleys, they built a grenade with the pin pulled. Behind those welch plugs are basically a debris trap. Crud will build up and sit there..... ...until someone tears the engine down and starts letting the degreaser and parts cleaners fly.


It's easy enough to figure out if an improperly installed pipe plug is your culprit. All you have to do is pull the fuel pump plate and look in there with a boroscope. These engines didn't come with pipe plugs, they came with welch plugs. If the builder didn't tap that location, that's not your culprit.


Being a 4.1 with a roller cam, my money's on lack of cam bore groove.
 
This happens a lot. Odd all the cams don't have the groove which seems important. Lol Why ? more bearing surface area or oversight?
 
More bearing surface area. And less damage to the actual bearing.

It was just a crutch for an ungrooved block. Then it stuck after block were grooved. When roller cams came out, they weren't made from the same blank, so they didn't come with that same weakness/flaw.
 
If the oil gallery plug behind the timing chain on the passenger side is to deep it will prevent oil from getting to passenger side lifters . I’m not certain on what side it is but I know that if that freeze plug is to deep it can ruin your day you can see in the picture the crossover port View attachment 337310View attachment 337309
Help needed here! Sorry to resurrect an old thread. Fresh build (COMP 206 roller with Johnson lifters) on stock 109 short block and NO OIL to #6 lifters, seems like very little to #2 and #4. Driver side is good so looking at restrictions on passenger side. Pressure is good, no visible damage to Sharp roller rockers or new pushrods. We primed on stand and 95% sure there was oil everywhere but not sure if I verified #6 specifically...plus that was about 2 years ago. Earl Brown front cover/pump mods and Power Source block and cam bearing mods. Oil passages cleaned and smoothed. Could oil gallery plug is a very likely culprit? How did I screw that up?
 
That makes no sense. The oil circuit give priority to the passenger side lifter galley. If you blew out the plug for that galley, it would starve the rest of the engine so the other bank would be even worse or just as bad.

Unless you have some trash in the lifter galley that's keeping the oil from making it down that tract. If that was the case, you'd still have oil everywhere else.
 
Thank you Earl. I don't see any leaking and pressure seems good so seems to rule out blowing out a plug? I cut the oil filter open so I'm going to put contents on a paper towel today just to have a look. It seems like oil is everywhere else...it must be plugged with trash? what can I do next?..or does it have to come out?
Not how this was supposed to go...I really appreciate all the help!
 
Earl Steve thanks for the useful info and video.

I have a 0012 block (3.8 S2 offcenter) which is non-grooved. I also have a crossover pipe in oil gallies on the back of the block and I would like to eliminate it. I have several billet roller cams and all but one has the groove on the #1 cam bearing journal. If I run a cam with the groove do I need a crossover in the rear and or a B-12B grooved cam bearing?

The one billet cam I have with no groove on the #1 cam journal was made like that on purpose and used in this 0012 block with the rear cross over and a normal non-grooved front cam bearing. Is this a better set up? Kind of confused on what to run with this set up?

Which is ideal for a 0012 non-grooved block?
1. Grooved #1 cam journal no cross over non-grooved block and cam bearing?
2. Same as above with rear crossover?
3. Grooved #1 cam journal with B-12B cam bearing w/wo rear crossover?
4. Non-grooved #1 cam journal non-grooved bearing with rear crossover?
 
Thank you Earl. I don't see any leaking and pressure seems good so seems to rule out blowing out a plug? I cut the oil filter open so I'm going to put contents on a paper towel today just to have a look. It seems like oil is everywhere else...it must be plugged with trash? what can I do next?..or does it have to come out?
Not how this was supposed to go...I really appreciate all the help!
Did you rotate the crank while priming?
 
Top