Knocking and low oil pressure

[jonesy2006]

I have a 1996 Ford Ranger, manual, 4.0 L. It has 160,000 miles on it. On starting it up, you can hear a knocking. When it's warmed up it's somewhat intermittent (it's sounds like it goes through a cycle. A knocking, then quiets, then more knocking). The oil pressure gauge is a little screwy, too. I'm not sure if it's the gauge or the actual oil pressure, but it usually runs a little lower than half-way and jumps down and runs to the lowest for normal range. I took it to a dealership and they guessed it was the lifter for the knocking. I didn't have a problem with the oil pressure at the time. It did jump every now and then but didn't go on the lowest in normal range. I wanted to know what you guys thought before I have to start paying. Thanks guys!

 

[289-tiger-]

Dumb question here but do you experience this after starting and shutting down the vehicle while cold or quickly? (i.e. "Let me move the truck out of your way so you can back out of the driveway.")
My 94 knocks and bangs when started after a short run cold. Anyone else seen this? My solution has been to run the truck at least 5 minutes before shutting down.

Good luck

 

[jonesy2006]

It happens whenever I start it as well as an intermittent knocking when it's warm. Is that what you mean? Don't worry about it. All replies welcome.

 

[Big Jim M]

There is a difference in CLICKING and KNOCKING sounds. What is generally referred to as KNOCKING would be lower noises. Pistons and rods make knocking sounds (usually). While valve noises are generally referred to as clicking. Clicking sounds can, most times, be repaired with rocker adjustments or longer push rods.

As your noise seems to come and go it should be repairable with one or the other..
A constant click might be a lifter that needs replacing... but those are unusual.

Mostly an engine will wear either the cup or the balls between the rocker and the rod, resulting in a bit too much clearance which causes the click.

A knock on the other hand would be more severe.. a cracked piston or worn rod parts.
Big Jim