OHV knock! Oil pressure numbers at idle?

[kindred4x]

Ok so i have been chasing down a knock in my 96 ohv for some time, here is a list of fixes i have done to try and fix it
-Clean MAF
-new lower intake manifold gasket
-new updated ford flex plate
-new updated crank to flexplate spacer
- multiple seafoam treatments
I am running amsoil 10-30 with amsoil filter, i just installed a real oil pressure gauge today because the knock happens at idle. When the motor is at operating temp i am reading 15psi. I searched and really couldn't find multiple solid readings at idle, just the 40-60 at 2000rpms reading. Does anybody know what oil pressire should be at idle on a ohv motor?

 

[rjcooperss396]

15 to 20psi at idle is normal. Have you listened to see where the knock is coming from? Is it a knock or more of a tap. When the hydraulic roller lifters go bad they will tap at idle but then quiet up once the oil pressure comes up. You may just have a lifter thats going bad.

 

[Willard]

Agreed. It is most likely a lifter. My motor has had it for at least 40,000 miles. Not really a big issue for the motor, just annoying.

If it was anything serious it probably would have already failed, at least depending on how long you have had the noise.

 

[kindred4x]

In my opinion it sounds like a knock, and the noise isn't consistant, sometimes it knocks, and sometimes it does not, most of it varies on engine temp. I have been chasing down this noise for about two years now and it's getting worse. I have put on the mechanics stethoscope but the noise bounces around so much that it is hard to pinpoint the location. all my friends say it's the bottom end of the motor, i have 146000 miles and from what im reading the bottom end of the ohv is pretty solid. im starting to lose my mind over this noise!

 

[Drew2o2]

mine taps until its warm. i too believe it is the lifters. i tried first gtx 5w30 with lucas hd oil stabilizer. it worked okay. best solution so far mobil one 5w30 with mobil filter and lucas full synthetic that is designed for stabilizing lighter oils like 5w20, 5w30 etc. try using a higher temp thermo stat to allow it to reach operating temperature quicker. when i bought the truck the previous stated his son thought it made funny noises for a while and i found the thermostat was damaged and wouldnt allow the truck to heat up causing the constant valvetrain noise. before the lucas problems i believe it would be possible to believe it was knocking even though it was the valvetrain because it was so loud. stant make s a 195 degree thermostat but i run the oem replacement one because its only cold a few months a year in ohio.

 

[manaen]

if it is the lifters sometimes a seafoam treatment in the oil can help to clean them out. usually they will get clogged up from poor oil choices or extended change intervals.

does it knock only at idle?

 

[AmsoilGuy]

Have you tried the Amsoil Engine Flush before you put Amsoil in the motor?

 

[Joe Dirt]

Mine taps too- hear it when I'm sitting in a drive thru.

I know it's just a lifter...

 

[kindred4x]

if it is the lifters sometimes a seafoam treatment in the oil can help to clean them out. usually they will get clogged up from poor oil choices or extended change intervals.

does it knock only at idle?

I always thought it just knocked at idle, because the intake, exhaust and knobby tires make it hard to listen while driving, but today i heard it knocking when i started driving from a stop light.

 

[kindred4x]

Have you tried the Amsoil Engine Flush before you put Amsoil in the motor?

Never really flushed the motor before. I always thought the synthetic oils would clean out the motor. I might give that a try

 

[2000StreetRod]

Piston slap

I recall reading that the OHV pistons were redesigned (don't remember when) which resulted in unharmful piston slap. That might be what some of you are hearing.

 

[AmsoilGuy]

Never really flushed the motor before. I always thought the synthetic oils would clean out the motor. I might give that a try

Its actually recommended by Amsoil that to get the extended change's out of their oil you should have used their engine flush before switching to Amsoil. I had a noisy injector in my 03 F-350 7.3L when I was running dyno oil. I did the complete flush and then switched it to Amsoil and it has been quiet ever since. Might just be some sludge built up inside the lifter and it might just need a good cleaning to get it out.. Worth a try anyways.

 

[manaen]

there is also a TSB about carbon buildup on the OHV motors The recomendation is to make sure that each run cycle includes running the motor to 3000 rpms to help clear out the carbon.

I would recommend doing both a motor flush (in the oil) and then perform a seafoam treatment to clear out the engine of carbon. If it is really bad you may need to change the plugs after to remove fouling, or maybe just remove them and clean each one/ Personally I have always been able to run the motor on the highway out of overdrive to clear out the seafoam and heat up/clear out the plugs.

 

[erc97z]

hi mine when starting cold makes like a grinding noise for like 3 seconds . then the oil pressure guage snaps into middle after about 3 minutes what could this be? could it be the pressure sensor