sml

I have noticed a rattly / pinging noise at higher rpms in my C4 manual .. generally above 5000rpm.

I haven't heard pinging on other cars, so I am not really sure if it is pinging or just a rattle .. perhaps the exhaust or something else but it comes from the rear of the car.

My testing has been at full throttle on flat roads. The rattle/ping is inconsistent .. sometimes just a bit of a noise that continues from 5k to 7k rpm ... and other times it is fine.

I am using 98 petrol.

Noises are hard to describe but hopefully you can offer some tips

Steve Weiner-Rennsport Systems

There are many reasons for the sounds you are hearing, but the very first thing I would check is the distributor drive belt.

You didn't say how many miles are on your car nor any details about when its last tune up occurred, what parts were replaced, or if its chipped, but this is a start,..

sml

Thanks Steve.

I only just bought the car but I do not think it is chipped.

Last service was 600 miles ago and they did plugs, leads, distributor caps .. but I still need to get the receipts from the previous owner to check other items.

Is the distributor belt part of the cap?

sml

If it only happens under load, would that a symptom that it is pinging?

Besides pinging, are there any other exhaust / engine rattles that it could be?

R6XTERRA

A broken dissy belt will make your car ping. Sounds more like a bunch of little nuts pinging around in your exhuast only under load though. You will not experience this at a stop just by revving your engine.

Jeff

wellcraft290

This belt will just break not wear out.

crg53

Definitely check the Dizzy belt first. If that is not the problem it could be something as simple as the heatshields on the cat.

sml

I have read that if it was pinging, then it would not continue through the rev range because it would be picked up by the knock sensors immediately. ie it would not continue from 5k all the way up to 7k.

I gave it a few revs when stationary and I could not hear the noise.

To describe the noise better ... perhaps add the work 'crackling' to my description!? Sometime just a few little odd crackles from 5k to 7k ... other times it is a little more consistent crackling.

AOW162435

Afterburner?


Andreas

sml

Maybe I should try to record a sound file!

Ken D

As the others have said, check the distributor belt for breakage. Check the various heat shields and engine tin to ensure they are fitted properly. Could be a broken element in the catalytic converter or muffler(s) which would be difficult to confirm without pulling the exhaust.

Beyond that you should have your mechanic put the car up on a lift and run it up to the affected RPM range. Another mechanic outside the car should then be able to pinpoint the source of the rattling/crackling/pinging/whatever.

sml

Thanks Ken. Sounds like a good approach.

If the noise is pinging, how dangerous is it to continue to drive the car? Can it cause damage to the engine?

wellcraft290

yes will and can destroy your motor. Do the simple test.
while the engine is idling there is two plug when your looking at your engine compartment all the way in the far left. They look identical and if you disconect one you should hear the motor just idle down slighty and same for the other. Just disconect one at a time. if the car stalls out then your belt is broken.

Steve Weiner-Rennsport Systems

Yessir, and it doesn't take long.

Pull the lower distributor cap off and see if the rotor turns freely.

Earlydays

Pinging was the symptom on my car after the dist. belt broke.
I believe if the belt is broken, the knock sensor cannot eliminate all pinging because it depends on both plugs working per cylinder.