Antonio

After the last race, I started hearing a noise that sounds like loose nuts and bolts shaken inside a metal coffee can. It seems to be coming from towards the rear of the valve train area but it is difficult to isolate. It flactuates from almost none to really loud between 2-3K and over 5K RPM. Otherwise the engine runs fine. Strong oil pressure, clean oil, no smoke, no shaking. I'm thinking broken valve spring. Anyone care to comment?

Mike Lindsey

You can bet it's not normal. Pull the cam tower before the damage and expense gets worse.

Jeremy Himsel

The easiest way to check for a broken valve spring to to put a vacuum gauge on it. You will get jumpy and fluctuating readings.

I do agree with Mike...You've got issues. I suspect it's more likely you have a collapsed lifter. I've had a few lose prime and it sounded awful but was able to isolate it with a stethoscope.

knfeparty

awesome...I think I have the same thing. Which is great considering the car just spent 3 months with the head off.

edit: mine actually only makes noise at idle and cleans up as soon as you add some throttle, but also otherwise no ill effects. Mine is also highly unlikely to be a valve spring since I could verify that they were fine not too long ago.

APKhaos

Not that I want to encourage you to take risks, but.......

I had a simple head gasket failure at the end of my first season with #11. Given I wanted to zero hour the engine anyway, I took it out for a winter rebuild.

Step 1 - drain the oil. Out comes a large chunk of metal, then some more. After a bit of hear scratching, it dawned on me that these were pieces of valve spring. DOOM!!

Long story short, there were no less than six broken valve springs. After very carefully inspecting and measuring everything during the rebuild, it turned out that there was no collateral damage. The broken bits had been flushed down the oil return galleys into the pan, and stayed there.

Clearly, this was a major piece of luck. Maybe you will be lucky too!

Antonio

Thinking back, the noise that I describe has gotten progressively louder. I'm not sure if this points to anything else. This motor has had many hard miles and it has definately given me my money's worth. After three sets of rod bearings I think it is ready for a top end rebuilt. I'll pull the cam tower this weekend and I'll post what I find. Thank you to all.

knfeparty

It turns out that my sound was, I do believe, a symptom of the top two bolts holding on the belt cover backing out.

Phew.

Antonio

The noise turned out to be severe resonance from the WG dump pipe. Somehow the noise was traveling up to the rear of the motor. Because it was coming on only at certain RPM ranges, it was challenging to get close to the source without help. Once I got the wife in the garage to work the throttle, it took all of 10 seconds to find the source. I tied down everything. I installed Lindsey’s vacuum rerouting kit and the old girl never sounded better. Notes to self: noise travels; don’t overlook the obvious.