82 d-150 4 spd 1 barrel lean burn.about 3 weeks ago i started noticing some valve rattle when accelerating esp going upgrade. it was about time for an oil change so this week i did the o/c with 10w30 max life semi synth,a pint wynn's friction modifier,and a microguard filter.this replaced a mix of max life semi synth ,pure guard 5w 30 semi synth and marvel mystery oil(the last 2 were topping off) and a baldwin filter.
soooo- now the valve rattle is slightly louder and at start up there is a knock from the rear of the valve cover.the knock lessens and goes away as the engine warms up.now the valve noise is accompanied by power loss when going upgrade.
any ideas guys?has the lean burn finally died?did my use of MMO loosen some crud up that may now be blocking an oil passage?do i need to add another pint of MMO to this o/c?is the 10w30 semi synth too thin?do i need to add some STP or hyper-lube to thicken up the oil?switch to a heavier weight oil?
also last week i replaced the dist. cap and rotor which seemed to add some snap to accel and quick cranking.not sure if that has anything to do with anything.
p.s. like many old dodges the oil gauge does not work,

First the oil is not too thin. If anything you dont want thicker oil. It might not get into the places it needs to. Sound like you have some part that is getting starved for oil.
Options: 1. look for a replacement engine and have it ready to go in.
2. Run Dans Engine soup thru the engine and see if that get the gunk out.
3. keep running the engine the same way you are now and see if it "fixes" its self.
..........
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

I suspect a sticky/collapsed/shot lifter for the start up knocking and if worn out could be rattling some when warmed up as well. If the leanburn crap(can you tell how I feel about those?)is not 'advancing ign properly your under power rattling/lack of power could be pinging/gas knocking.Get a oil pressure gauge hooked up,if you're lacking pressure when warmed up well there's your problem,motor just might be wooped.Good luck.

_________________
83 B-150 slant 6,4 speed. 79 B-300 360 pathfinder 4x4. 74 W-300 318 4x4 git-r-done 80 B-100 sl6,4speed

Here is an update.After the oil change the the knock went away and came back. So i added a pint of marvel mystery oil and as of this a.m. the knock has gone away.I just have a little tic .That tic has been there since i bought the truck.
Now here is an observation.The day of the oil change after driving for a while the oil on the dipstick was a charcoal color that seemed to have a lot of particulate matter.Now a few days have passed and the oil is now more of a brownish color.I think i had a bit of buildup/sludge that was blocking an oil passage ,causing the knock.The new oil and MMO seems to have dissolved the bit of debris and the oil filter is slowly filtering out the particulates.
I hope this is what is happening.iI really need to take the valve cover off and check for build up.This way i can get an idea of the cleaning power of MMO,when i check it again at a later date.
btw-my daily commute is a 75 mile round trip at 55-65 mph.

If you think the oil has been contaminated by sludge then at least change the filter. Once it goes into bypass all that stuff will just go thru your bearings.
My02.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

I have an 84 hydro motor in my daily driver that had the same tick you mention. It went away after it warmed up and disappeared completely after a couple of oil changes. I suspect it was just a clogged or not-pumped-up-fully lifter.

_________________
If it was easy, everybody would be doing it.

is one of Mopars worst efforts and it's almost criminal they were allowed to foist it on an unsuspecting populace.Offer me a coupla hundred bucks and I will take it off your hands and save you much embarrasment!
Good luck
robert in wetanmucky
columbus

Got the same sticky lifter with my 86 Ram. Old Mopar wrench suggested one cup of ATF per oil change to assist in lubing. I can tell when I am getting close to 3000 miles when the ticking starts back up.

_________________
86 D100 short bed A833, lean burn deleted.
07 Honda Accord EX-L V6
03 Toyota Highlander - 305k and still going strong
13 Toyota Highlander - 151k

My 87 hydraulic motor had a intermittent tick that turned out to be a bad rocker arm

Which either caused the lifter to not fully pump up, or went bad because of it. IIRC, the #6 cylinder is where the little "beehive" bolt is that provides the oil for the hydraulic lifter motor. Slants oil like AMCs; the oil goes down through the pushrod to pump up the lifters, and not the other way like a chev or ferd.

If I'm wrong, please correct me on this.

_________________
If it was easy, everybody would be doing it.