Troubleshooting noisy hydraulic lifters

Anyone have any troubleshooting suggestions on why my hydraulic lifters are so noisy? Here's the situation. I built this engine about about 15 months ago and I have been street driving (about 100 miles per week) it ever since with a trip to the track about once a month. The engine is a 505 built off a 440 block. The first cam was a competition cams flat tappet hydraulic. It was only 460/470 lift with the recommended cc springs. At different times I had both the stock rockers and some adjustable procomp stainless roller tipped rockers on it. There was no difference in the noise level from either set of rockers. When the lifter noise was most noticable was on cold start up and it was always isolated to the intake valve of #6 cylinder. Sometimes before I started the engine I would pull the valve cover and this particular lifter was always soft or springy like all the oil had leaked out of it. It would quieten down after about 2 to 3 minutes of running and then after getting completely warmed up there was a very low level noise coming from most of the lifters. Just barely above I would consider normal in a stock engine. My thinking was just probably a faulty lifter.

After running the engine this way for a year I got tired of listening to the noise. I was wanting a little more cam anyway so I upgraded to a Sig Erson hydraulic roller and put scorpion hydraulic rollers on it. It is only .510 lift, so nothing to really stress valve train components. I used their recommend springs with it which gave about 320 pounds open pressure. Still have the procomp stainless rockers on it. Every thing was nice and quiet for 2 to 3 weeks of driving and then the cold start up problem reappeared. However, still nice and quiet when warmed up. The engine runs great, has good power and never misses a beat. But I don't like the noise and want to stop it.

I have recently pulled the intake and checked the lifters, pushrods and rockers for any sign of problem. Everything looks good.

I am thinking something in the oiling system might be causing this but not sure where to start checking. It has a 7qt oil pan, melling high volume oil pump, 1/2 inch pickup and I run the wix 51515 oil filter. Bearing clearences are .002 to .0025 on both rods and mains. Mains are 3/4 groove. Oil pressure when hot runs from 30 psi at idle (about 800 rpm) to about 70 psi at 5000 rpm.

Any troubleshooting suggestions would sure be appreciated.


Author: Mopar