When my engine begins to warm up from a cold start everything sounds normal, but within a minute or so, I begin to hear a low ticking sound that seems to come from the bottom end of the motor (I can hear it really well by the drivers side front tire).

After a few minutes, the noise gradually becomes louder. It seems to increase in speed with idle, but fades and disappears right around 2,000 to 2,500rpms.

I notice that the noise is much quieter near the time for an oil change and is much louder and distinct after a fresh oil change.

At the advice of a technican I know, I ran a full load of "Marvel Mystery Oil" for a time of 30 minutes, in which time the noise was completely non-existant. However, as soon as I replaced it with standard engine oil, the noise returned in full force.

I am completely at a loss on this one.. Any thoughts?

 

rod bearing- hows ur oil pressure

 

Oil pressure seems to be fine. When cold, pressure is above the middle mark, and normal temperature it stays in the middle, sometimes drops slightly below. I usually change my oil a few hundred miles before its due and use Valvoline 10-30. For the past two oil changes I have been using "Lucus Oil Stabolizer" to see if that helped, but had no effect.

 

I had same problem thought it was a rod bearing as well, turned out to be an exhaust leak.

 

Where was your exhaust leak? I looked around the headers but didn't see anything abnormal? How did you correct your problem?

 

It was where the Y-pipe meets the mid-pipe and I just took off the Y-pipe and re-welded it.

 

I'll check it out anyway... the only thing that doesn't add up about the exhaust leak theory is the fact that the oil effects the sound.

 

Well I dont know if thats the case since, when the engine warms up the oil pressure goes down alittle as it heats up, aslo that ticking noise goes away when the engine heats up two. If you had a rod knocking it wouldnt go away if the engine was cold or hot it would be there regardless. Iam pretty sure its an exhaust leak.

 

Usually, the issue comes from the oil thinning out when it reaches operating temperature. If you are using a standard 10W30 oil, and it makes no noise when cold but gets louder as the engine gets warmer, then its probalby due to increased clearances in the bearings. To test this, you can run a heavy(and by heavy I'm talking 20W50) weight oil and see if the noise stays. If the noise goes away, then the thicker oil is taking up the space in the bearings, and keeping them from contacting each other. If the noise is still there, then it is either an indication that the engine bearings are toasted, or there is a completly different problem altogether....

 

Great advice. I used 20w50 when I was trying to get every last mile out of my last engine before it finally blew.