What is ticking from front oil pan?

I have a 71 250 W114/M130 with 170K miles. Oil pressure 45 off idle, 25 at idle. No smoke. No vibration, really sweet and quiet.

There is a ticking/clacking sound (sorta like a bad tappet) coming from the front of the oil pan.

I pulled each plug wire to see if a rod knock would quiet down, no luck.

Question; Does the oil pump make noise? Does it make noise when it gets old?
Is the oil pump loose?

Would a loose chain or tensioner/slide make this regular ticking noise?

[ctaylor738]

The oil pump is shaft-driven and I don't think there is anything to make a ticking sound.

My initial thought is that you have a loose chain either because of stretch or the hydraulic chain tensioner may not be keeping it tight. It is not going to get better with age, so you might wanna get it checked sooner rather than later.

[gmask]

Originally posted by Georgia Brown

There is a ticking/clacking sound (sorta like a bad tappet) coming from the front of the oil pan.

OIl pan? Do you mean from the front of the valve cover?

I'm guessing that it is improper valve clearance or a worn camshaft lobe. Take the valve cover off and see if any of the lobes are worn or have large grooves in them. Are any of the rockers really loose or really tight?

[240 Ed]

gmask,

I am helping Bob (Georgia Brown) with this noise.

It is definetely coming from the lower pan area in the front. I was wondering what else was down there...
I guess just the oil pump, front sprocket, and big ends.

The engine is as sweet as can be, no vibration, etc.

What is a "pressure relief valve" and where is it?

[ctaylor738]

To my knowledge, the pressure relief valve on a M130 is in the oil filter housing. Since the pressure output from the pump increases with engine speed, the relief valve caps the pressure at (I think) 3.5 bar by diverting some oil back to the pan.