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.

@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.

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.

I pressurized the system using an air tank half filled with oil. 60 PSI with 1/2 inch hose. I had the heads removed and plugged the oil passages to the head. I plugged the turbo oil feed line. All of the mains leaked the same amount of oil. All coming at the same time The return coming from the air compressor seemed normal. The return from the centrifuge filter was the same as the air compressor. (I plugged this filter housing in my second test). The oil pump leaked a small amount of oil. The cam bearings did not seem to leak oil at all. Looking at the oil flow diagram, it shows that oil flow goes first to the mains, across the upper main bearing, and to the cam. See figure A (16&17). How does the oil flow across the main bearing? I attached pictures of my upper main. Is there a passage in the block that allows oil to flow on the outside of the upper mains? Should there not be two holes, or what am I missing here? IMG_0410.HEIC IMG_0409.HEIC

Hooking air into the oil system did not do much. I plugged into a port after the oil cooler and before the oil filters. Initially the air pushed out the oil inside the filters, but nothing out of the ordinary was occurring as far as I could tell. After the oil was pushed out, I tried to track down the leak using soapy water. Majority of the air just came out of #1 main, but it plasti-gauges to .025. Air did not come out of the piston coolers at all. Air did not come out of the small drain holes next to the cam. Then I removed the oil pump to check the air flow through the oil cooler; It seemed fine to me. Then I pulled the reman heads to check for a flipped head gasket. (It can almost be flipped, but the dowel pins will keep it from lining up 100%). I pressurized the oil galley in the heads and they did not leak air. I checked the tubes that come off of #2 & #5 cam bearings and go to the head. They did not looked cracked or broken. @theakerstwo I have not had the oil filter housing off. @fjh The truck does have 3 oil filters (2 paper, 1 centrifugal), but over the past 6 years I have always had about 9 gallons of 15w40 in it. My next step is to build a pressurized oil tank to hook into the system and watch the oil flow with the heads removed.

@Joey Mack 1. I have taken apart the spring and piston on both new and old oil pumps. Both are smooth, clean, no scratches, and spring tension is good IMO. I don't have a spring tester. 2. I have taken apart the oil pressure relief valve. Same verdict that it was good. 3. I have taken apart the piston cooling relief valve. Same verdict that it was good. @theakerstwo That plug has not been touched (engine and transmission stayed together) If it was, would there not be oil everywhere? Inspection plate on transmission is not installed. I am thinking of hooking about 10 psi of shop air to the port before the inlet of the oil cooler (only thing before this point is oil pump), and laying under the engine to maybe hear the leak or spray with soapy water to find it. Thoughts on this? A service manager at Bruckner's Amarillo had said he did something similar with nitrogen a few decades ago...

@theakerstwo Oil level stays the same after running 50 miles, and low oil pressure is occurring with fresh oil after 5 minutes of warmup. I have not taken any oil samples.

Is the oil pump mounted to the block without a gasket? That is how I installed it. I have the gasket between the suction tube and the oil pump in place.

Plasti-gauged 2(.0015), 5 (.002), and 7(.0015). Oil Flow show to go first to pressure relief valve. We pulled it apart and inspected; everything looked fine. Oil flow then goes to oil cooler. We checked oil pressure at the intake of oil cooler, and it matched the other readings we get on gauge at oil filter. @Joey Mack 1. Top end had oil flow but still low pressure. (Rev it up to 35psi and the jakes will then work.) 2. New Oil Pump gear was the same as old. We reinstalled the old one at the moment to make sure it was not our problem. @br549 I did not take the piston coolers out to do the liners. They do not look damaged when looking at them with the pan off.

Cam went in smoothly, no problems. I will jack up the crank and plasti-gauge 2 & 5. I was thinking that the oil pressure was cam related because my oil flow diagram (attached) shows oil flow from cam to heads. Mack oil supply.pdf

I recently rebuilt my E6 350 after a cam lobe/lifter failure. Truck has 750k. I decided to pull heads and pan to inspect, and I decided on an inframe. PAI Kit; Reman heads, reman turbo, reman oil pump, new rods and mains, new lifter, new camshaft, original cam bearings, original piston head bearings. Truck had 30psi idle and 60psi @1600 operating temp. Truck now has 18psi idle and 35psi @1600 operating temp. The mechanic who started the inframe (no longer employed) put the upper #4 main in #7, (#4 upper was initially installed correctly. I ordered another main bearing kit after he said that we were missing the #4 upper main.) Psi was down to 10 with the incorrect bearing in #7. I finished the inframe after the mechanic was fired; mains 1-4, rods, heads, liners, pistons, cam. Started the engine, resolved the main bearing issue, and now I am stuck with this low oil pressure. Pulled all rods and mains to inspect. Plasti-gauged 2 mains and 2 rods (Both were in spec). Initial thought was that #7 did not feed the corresponding cam journal with oil when it had the incorrect bearing. Is this the direction I need to go? I looked at the installed cam when the pan was off and could not see any problems. Oil pressure will get up to 75 when cold. Pressure relief valve is clean. Put old oil pump in, same issue. Pulled filter by-pass apart, everything looked fine. Plumbed mechanical gauge before and after filters to verify correct readings and good filters. Jakes (not working now) still have all plugs in the rocker shaft.