Eli K

Hi all,

Just got back from a DE in Mid-Ohio. Great time! with one exception.
During the last session, I went to pass another car and hit the rev-limiter in third gear . After finishing the session and pulling into the pit, the valves on the driver's side were obnoxiously loud.
The car is very much drivable, but the noise is unbearable. Any ideas, as to what it may be? I'm hoping for the best (a broken valve spring??? ), don't even want to start thinking about the worst case scenario...
The car is a 91 C2 with 133,000 on the odometer, engine has never been touched. Car uses about 2/3 of a quart of oil between oil changes (every 3000 miles). Minor leaks, just a pea sized drop on the garage floor after driving. Doesn’t smoke.

springer3

If the rev limiter worked, it is hard to imagine the overspeed damaged anything major. My money is on a broken valve spring, or possibly a broken rocker. The latter would cause a bad miss, so the valve spring is the best bet. They can be changed without pulling the heads. By all means do the compression test and report back.

bhensarl

As long as you don't mean, "I hit the rev limiter... due to an untimely downshift" it shouldn't be anything horrific. Here's hoping it's relatively minor.
Brian

PC2

When was your last valve adjustment? Could be you just need an adjustment. I know my valves are a bit louder/looser after each event.

Eli K

The valves are due for an adjustment, but this sounds a bit louder than average. The over-rev was definately not due to a downshift, but hit on acceleration in 3rd gear.
We'll see what tomorrow brings...I had no choice but to drive the car 400 miles home , stayed under 3000 RPM hopefully didn't cause any additional damage

Smokin

Is the noise loud at all times or just under acceleration? I'm thinking broken spring or they need a severe adjustment. My old 77' did this (w/ similar miles) but only under load!

Ken964

It could also be your alternator belt has failed. It sometimes sounds like valves when it gets real bad.

Ken

Eli K

Hmm...didn't even think of the belt, will check first thing tomorrow! Thanks for the tip

Eli K

Here is a link to an audio file of what my engine sounds now at around 3000 RPM, half way through the middle I let of the throttle and let it idle for a bit. What do you think???

ENGINE SOUND CLIP

Eli K

Tonight I checked the distributor belt. All is intact. Both rotors are rotating insynch while I manually turn the fan.
I'm praying for a busted valve spring...will find out later in the week, after I open her up...

Wachuko

Valve noise alright... most likely a broken spring. Let us know what you find when you take the valve covers off.

Eli K

Let's hope that's all it is, as oppose to bent valves....

axl911

That is bad. If it was me, I would do the following. Don't run the car anymore that necessary. Perform a compression test check to see if the the valves are bent. Perform a leak down test to see isolate it down further to intake or exhaust valve. If both compression and leakdown are good, then pull the valve covers to inspect the valve train including valve spring and rocker arms.

BrokeAss

ooooo that sounds expensive!
Ditto AXL911's comments - don't run it anymore. Call a flatbed and grab your checkbook.

ventoGT

Yikes. I wonder if Steve Weiner or Viken can pop over here and have a listen--they may be able to at least point you in the right direction