If you can get the car on a lift, with the engine running, try to determine the general area where the ticking is coming from.  The best listening device for me is a long screwdriver.  Place the butt end of handle against your ear and touch with the screwdriver's tip where you want to listen.  You'll be surprised what a great stethoscope it is!

Published in the October 2023 issue of “Die Porsche Kassette”

CLUNK:

It's the most common sound and usually comes from the front end.  

If it happens while driving on bad roads, it's usually a ball joint that's worn.

Ball joints are protected with a flexible dust boot.  When the boot tears, it can allow the lubricating grease to egress and road grime to ingress, eventually destroying the joint.


For more information on Weird Noises and more, please visit my weibsite: www PedrosGarage.com.



Happy Porsche'ing,

Pedro







2023 Technolab / PedrosGarage.com

A CLUNK is very different from a tick, which has nothing to do with a hiss, a click, a squeal, a knock, a pop, a rattle, a whistle or a bang.

In this article we will try to explain the difference between them and how to figure out what they mean.

Usually, the drop links are the first to go, but control arms, trailing arms, steering arms, etc. all have ball joints that wear out with mileage and time.


SQUEAK:

I mention squeaking here because it is usually a precursor to clunking.

If your car starts squeaking when the suspension is depressed, it may be one or more of the ball joints that has dried out and is letting you know.

When you determine which one it is, check the condition of its dust boot.  If the boot is in good shape, try to inject some lubricant (high quality lithium grease) into the boot with a syringe or with and aerosol straw tube.


If it quiets down you know it's living on borrowed time and will need to be replaced soon, but at least it should be quiet for a while.


TICK, TICK, TICK:

So many things can tick!

Generally, ticking sounds are heard coming from the engine itself.

First, check if the ticking varies with engine speed or car speed.  That will tell you if it's coming from the engine as you rev it, with the clutch depressed (or in neutral), or if its coming from the drivetrain as you accelerate.

A shredding poly-ribbed belt can tick as it goes around.

The fuel injectors (all six of them) can tick quite loudly.

The lifters, especially if the oil level is low can tick, tick, tick.

Rotational in origin: Bad serpentine belt, debris in a brake rotor, a pebble or nail in a tire tread, a dried out CVJ.

Non Rotational: A loud fuel injector, or a sticky lifter.

Believe it or not, a very loud, metallic-sounding tick can also be caused by a loose sparkplug.

KNOCK, KNOCK:

If you can hear knocking sounds from your engine, get it checked out ASAP, something could be seriously wrong!

A knowledgeable tech can tell you if its serious or if can be easily fixed.

What's generally called engine knocking really sounds more like clattering and is usually due to using a lower octane grade than recommended.  On high compression engines, you need to use high octane gasoline to avoid pre-ignition and knocking which can damage the engine.  Fortunately, most modern Porsches have automatic knock sensors that will retard timing to avoid pre-ignition (but you will lose power).


BANG, POP:

A loud BANG, like a gunshot, is usually a backfire.  

Backfiring happens when unburnt fuel comes out of the engine and gets ignited in the exhaust pipe.

This could be due to a vacuum or exhaust leak or a problem with one of the catalytic converters.


It can also happen on the intake side, at the throttle body and could indicate an issue with the fuel and or the injection system, caused by a blocked fuel filter, bad spark plugs, or damaged catalytic converter(s).


GRIND:

If the grinding happens when shifting, you probably have an issue with a synchro in the transmission, which makes your gears not mesh at a synchronized speed and therefore grind.

A dried-out CV Joint (drive axle) or a failing wheel bearing can also grind quite loudly.

If you hear grinding while applying the brakes, your brake pads are probably worn or you may have caught some debris between a brake rotor (disc) and its pad.


HISS:

A vacuum leak while accelerating makes a loud hiss.

A fluid leak dripping on a hot engine surface can also hiss.

A hot engine venting steam as well as a punctured tire also hiss.

RATTLE:

Rattling under the car means that something is loose and making noise as it vibrates.

Generally, a heat shield in place over the catalytic converters is one of the most common culprits.  They are mounted with hardware that deteriorates in time and allow them to vibrate and create rattling.


WHISTLE:

A very distinct and loud “coke bottle” whistle is most likely the air-oil separator (AOS).

If the inside membrane tears, it can create this unique sound.



Other possible whistlers are:

• The hood and bumper out of    alignment

• One or both of the side    mirrors

• Side window/door seal

ROAR:

Most of our cars produce a beautiful roar as we accelerate, some call it the symphony in flat-6, but if your exhaust note changes all of the sudden to a loud roar, something happened to the exhaust system.


The exhaust manifold may have cracked or one of he gaskets is allowing exhaust to freely escape.

The muffler may be damaged or an exhaust pipe clamp could have rusted out and become loose.


SQUEAL:

A loud squeal when you rev the engine, especially when cold, is one of the earliest to diagnose.

The belt is most likely loose and slipping on the pulley.

It could be worn and in need of replacement, or the tensiometer pulley may have lost its tension.


If the squeal is coming from the wheels without using the brakes, you probably have some debris between a brake rotor and its backing plate.

If it happens when applying the brakes, then your brake pads may be worn out …

… and, if it's coming from your tires, you may need to back off the gas pedal!