[MuscleStang89]

Ok, my truck has been out of the shop about 2 weeks after having a valve job, new dizzy, and egr valve. Haven't driven it much, just around town maybe 10 - 15 min at a time. It ran great, much better than the day I bought it.

Yesterday after about a 20 min drive down the highway it felt sluggish, heard lifters ticking, and saw no oil pressure. All 3 happened in about 30 seconds of each other. I turned off the engine and coasted off the road. While wait for my brother to come give me a tow I cranked it up to see what I could. Pressure was back and the lifters stopped ticking. Checked oil level before doing this. I get turned around under its own power and I see the oil gauge flopping around then drop off.... killed the motor real quick again.... get towed to my brothers house. I ran it again just enough to get off the road, and it had good oil pressure again.

So after all that, I'm thinking the pump pick up is blocked with sludge or the pump is on its way out. What do y'all think?

 

[vfourmax]

Definately sounds like the pick up screen picking up trash or gunk while running and then when you shut it down some of the trash is falling off opening up a little flow for a bit when you first recrank it until it picks up the trash again.

I can remember that when factory timing gears had the nylon teeth after they got high miles and age on them the nylon would break off in little pieces and fall into the oil pan and do the same thing as what you are describing.

Was the engine gunked up inside when they pulled the heads? May have knocked some chunks loose or pieces of gasket material when they cleaned the block causing your problem. I ask this because it just started after you had the top end done very recently.

Time to pull the oil pan and take a look see.

 

[davidhicks16]

I had the same problem, turned out to be cam bearings.

Dose your oil pressure drop off when your engine gets to operating temp?

 

[MuscleStang89]

I've only had the problem once. I'm getting it towed back to my house tomorrow and then I'll put a real pressure gauge on and see what's up. I'm wanting to make sure I'm thinking in the right direction. Can the oil pan be pulled without taking the motor out (unbolt the motor mounts and lift the motor)?

 

[davidhicks16]

Jack the frame let the suspension droop and it should clear.

 

[nelbur]

I'm not sure what your problem is, but before you do anything heroic, I would replace the oil filter. It seems possible that the filter could plug up and collapse, blocking flow and forcing the oil through your overpressure valve. I believe your oil pump is driven off your distributor shaft, so I expect it is still pumping, and it seems to me unlikely that your oil is so bad it could clog up the pickup screen. I think your oil sender is down stream of the filter, but I am not sure. I do know that oil filters are easy to change, so I would try it.

 

[davidhicks16]

I have heard of people running a wix of equivalent quality filter and picking up oil pressure.

 

[MuscleStang89]

I'll try a new filter, but it's new too so I'm not gunna bet on it.

 

[Kingfish999]

im guessing main and rod bearings. if you rev the engine abit, see if the pressure kicks back up. maby try thicker oil. could be the screen. could be the filter. start simple and work up till its fixed