Walker's work doing's

[walkerv]

Yes mechanical guage reads same as my scanner and vcads. The actual guage in dash is a little low lower it gets . Oil pump is a new reman took it apart and inspected it and measured it prv is with the pump i dismantled that as well and applied a bit of lapping compound to be sure plunger was sealing. Thought for sure the standard rod bearing on a 10 under crank was the culprit. Full speed oil pressure in spec. What i am seeing is psi fluctuations when around half throttle goes 39 psi up to 50 then back down , i am currently triing to get to one of our junker engines to have a look at the oil filter bypass valve in the filter head , my whole problem with this engine is the short block was assembled by someone that no longer wotks here and i cannot find out what all he put into it. I will take a picture of the oil flow diagram when i get a chance i know rods and mains are good for sure . I dont know about cam bearings aux shaft bearings or the idler gear which is also fed oil. To me it sounded kinda noisy in the front cover , i have not been in there yet. Oil pressure is sensor is in the filter head which is first spot the oil goes after leaving pump then it goes straight to the mains and goes put from there . Im almost wondering if my filter head has a crack in it now that im thinking about it . It is a mack etech with flat plate cooler set up if anyone is familer with that arrangment 2004 truck

 

[walkerv]

Ok picture one is filter bypass not servicable but just dumps into what should be clean oil supply . Picture 2 is supply from pump to filters , picture 3 is clean oil supply to mains. Picture 4 is centrimax drain to crankcase . I have never seen one of these crack but it is a possibility.

 

[walkerv]

 

[walkerv]

Have you had the oil pump out of it, or the engine oil PRV..?
What maximum pressure did it go to with cold oil..?

I have added a few things to my post nige i wasnt really paying attention to cold oil pressure at idle it had 45-50 but i did not floor it till it was warmed up some and pressure was already dropping, i was trying to hurry up move my crap and get it outside before anyone in the office came out cause for some reason the smells make it into the offices even with the doors open. I have a nutty feeling whatever is going on is what caused the rebuild to begin with, i was told it spun a rod bearing but im still wondering how one of the rocker shafts got broken. I need the paul harvey version right quick and in a hurry. There is also a soft plug with a precision hole in it at the front of the aux shaft on these engines i can check that pretty easy just have to pop a cover off where a front cover mounted powersteer pump would go .if that checks out im going to pull the oil filter pedestal and figure out a way i can pressure test it . Im thinking a blank plate that i can bolt to it to pressurize the oil sides but i have to figure out a way to stop the centrimax filter from getting any supply , then if i get air or oil coming out the drain portion of the filter stand i will have my culprit, sounds easy to type it now i have to implement it , oil pressure sensor is in the filter stand so it kinda makes sense to me to check there for an issue before i go hog wild on it again.

 

[Nige]

I was also rushing a bit when I posted ........ I should have said "What maximum pressure did it go to at low idle with cold oil..?" Then you can compare apples with apples of oil pressure cold versus "warm".

 

[Wes J]

I was always taught that a good engine should have 10 psi for every 100 RPM at cold start up.

 

[DMiller]

Alright a drifted thought, is there any possible chance the feed to the rocker shafts is either loose or not seated, cracked, or possibly just blowing oil? One of the first failures I ever had on an engine we put the incorrect bolt in a rocker arm shaft retainer, with a incorrect length, torqued up but failed to draw down, oil was spraying like a blowout well under the cover. Or maybe incorrect head gaskets again not sealing the oil gallery?

 

[kshansen]

Alright a drifted thought, is there any possible chance the feed to the rocker shafts is either loose or not seated, cracked, or possibly just blowing oil? One of the first failures I ever had on an engine we put the incorrect bolt in a rocker arm shaft retainer, with a incorrect length, torqued up but failed to draw down, oil was spraying like a blowout well under the cover. Or maybe incorrect head gaskets again not sealing the oil gallery?

Maybe pull valve covers and start up to see how much flow is coming up there? Look down the push rod tube hole to see if there is major flow from a head gasket problem?

Forget, is there an orifice in the Centri-Max filter housing that could be missing?

One last thought that could cause a big mess. Do you have access to something to supply a good flow of oil? Say like a filter cart, electric powered pump or even an air powered barrel pump? Just thinking about somehow hooking in a supply of oil to the engine with the pan and valve covers off to see where the oil is going. We had a "Bearing Leak Detector" that was basically like a portable air tank that you could fill with oil and connect air hose to to push the oil out. I believe it was sold by Federal Mogul to be used to check for bad bearings in an engine.

 

[DMiller]

I used to have one, traded it off years ago for some other tools was a old air tank of a FL8664 Freightliner. Welded in a 2" pipe nipple(In end cap), made legs to stand on end could put a gallon of oil thru an engine in short order so put a needle valve on the outlet to control that flow.

 

[kshansen]

I used to have one, traded it off years ago for some other tools was a old air tank of a FL8664 Freightliner. Welded in a 2" pipe nipple(In end cap), made legs to stand on end could put a gallon of oil thru an engine in short order so put a needle valve on the outlet to control that flow.

Took a little looking and cutting and pasting but found a short advertisement for the one we had at the quarry, not sure but it may have followed me home when I retired! The advertisement below is out of a Pit and Quarry Magazine dated September 1947!

 

[DMiller]

When you connect a air supply to these put a regulator on it, dial it back to where you show the PSI the engine runs at. Otherwise in a Blip of seconds the tank goes DRY!! Do NOT ask.

 

[walkerv]

All good suggestion no matter what i do a mess is no big deal the post the centrimax filter sits on is the orfice. Its rained so i am currently flooded with dump truck issues cuz truck drivers hate driving the spares. I got into a run hot/ bad fan belt and tensioner and a face plugged rad this morning , then a wheel seal on a peterbilt , have to do the other 3 drive brakes in the morning and both tandems on its trailer, then maybe i can clean up my mess on the project and get to inspecting some things. I stripped a used filter pedestal we had laying around gonna clean that up and change that first i have come up with a way to pressurize the old pedestal once i get it off, i think im going to pull that left steer tire to make my access a lot easier seeing how it has 425 steers on it and that left side needs a wheel seal anyways .will post on what i find out .

 

[Old Doug]

Dont you love working on trucks were things can change like the weather or seasons and all hell brakes lose. I work on propane trucks and it has wormed up so the drivers have nothing to do but think what is wrong.

 

[walkerv]

Dont you love working on trucks were things can change like the weather or seasons and all hell brakes lose. I work on propane trucks and it has wormed up so the drivers have nothing to do but think what is wrong.

Yeah when its raining the drivers are usually shut down unless owner needs chicken litter hualed or jobs need stone. So i pretty much have to drop what im doing to address truck issues, i have become pretty effecient at clearing out the shop though , i usually start a truck and fumigate the place i like the way a good running mack smells lol everyone else not so much

 

[walkerv]

Quick update on project mack changed out the oil filter pedestal with a good used one found gasket was installed correctly so that was 2 possible issues killed at once , removed valve covers after oil was warmed no major leaks up there that can be seen made a huge mess though. Did notice that the front rocker shaft seems to have just a little less pressure then rear. Did a little studying on an old torn Apart block we have stashed found the oil rifle for the lifters is 2 sections just like the mains and there is a pipe plug behind the cam gear im suspect is missing. There is a plug on the block that goes to the front journal of the aux shaft i rigged my blow gun up to it and hit the trigger and had instant air out the breather on front cover no gurgle or hesitation at all. Dropped the pan air is definatly coming from up in the cover. See the lub diagram i posted previously . In going to take front cover off tommorrow once i get boss mans truck taken care off . I tried getting the boroscope up in the cover thru the breather location not enough room so in going to have to go in for a visual . Going to carefully mark one piston cooling jet also and make sure it has its rubber seal installed also.

 

[DMiller]

This is why I hated following someone else's work, cannot ever trust anything done to the level you would have yourself done.

 

[kshansen]

This is why I hated following someone else's work, cannot ever trust anything done to the level you would have yourself done.

I could see where someone had removed the plugs to run a gun cleaning brush down the bores to be sure everything was nice and clean and then lunch bell sounded while installing the plugs or that emergency job came up and they had to leave the shop.

When something happened for me I tried to leave a note or something to remind me where I left off. Something simple like stick a pencil in the hole that the plug was missing from.

 

[walkerv]

Ok cover is off on the mack all plugs are in place under front cover , i made a classic inframe mistake plasti gauging main crank bearings , who can tell me what i did or didnt do ? Dmiller you are exactly correct following behind people sucks especially when they obviously were not paying attention putting this engine together.

 

[DB2]

Let the weight of the shaft give an incorrect reading?

 

[kshansen]

Let the weight of the shaft give an incorrect reading?

That sounds like an easy one to make if you forget to somehow support the weight of the crank.

I'm thinking there maybe two or three common methods. One could use a couple small hydraulic jacks to lift the crank while doing the gauging. Another way I could see would be to remove caps either side of bearing being measured and stick a couple layers of cardboard between crank and bearing then snug up the caps enough to lift crank.

Or you could roll truck over on it's top and do them!