Not so obvious

Published in the April 2014 issue of “Die Porsche Kassette”

Many of these parts can be replaced as a DIY project.

To learn more about wear items and parts in general, and for detailed DIY Instructions on these and other projects, please visit my website at: wwwPedrosGarage.com.


Happy Porsche’ing,








Ⓒ2014 Technolab / PedrosGarage.com

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The least obvious is the Front Engine Mount (in the Boxsters and Caymans) or the Transmission Mount in the Carreras.

This mount which is made of rubber and supports half the weight of the engine/transmission while it dampens engine vibrations.

Although the new mounts from 2008 are much better than the old ones from 1997 they still crack and wear out and should be replaced regularly.  If allowed to wear down they will affect shifting, could cause damage to the transmission mounts  in the Boxster/Cayman or the Rear Motor Mounts in the Carrera as well as quick deterioration of the Continuos Velocity Joints (CVJ) and half-axles.

Most Porsche owners regularly check tire tread wear, tire pressures, oil level, oil change interval, brake pad and brake rotor wear, brake fluid flush and service schedule intervals.  In other words, the obvious stuff.

And that’s great, but there are several other wear items that are not so obvious that many times get overlooked by DIY’ers and even by some shops:

These mounts can only be properly inspected when removed, so many people tend to forget about them until many times too late.

As a rule of thumb, after 45,000 miles they should be inspected because most likely they have already cracked.

Its cost is around $150.00 plus a couple of hours labor to replace.

There are remanufactured mounts available at considerable savings, since what wears is just the rubber center, not the structure.

When this happens it is no longer balanced and starts to deteriorate its seal and bearing.  When it fails, all coolant will be lost, rendering the car undrivable.

The water pump is more expensive than the previous wear items, costing around $300.00 for the part, three to four hours labor plus materials, such as gaskets, coolant concentrate, distilled water, etc.

Although this next piece of equipment can last a bit longer than the two above, contrary to them if and when it fails it will leave you stranded.

I’m referring to the water pump.

Water pumps generally last well over 100,000 miles but I have seen them fail at just about any mileage.

People who constantly open the coolant reservoir, generally have the highest failure rates.  Opening the coolant cap, especially when hot, allows air into the closed-loop cooling system.  When air circulates through the system and passes through the water pump it will cavitate and may break one or more of its impeller vanes. 

Another one of the wear items is the Air/Oil Separator found in all of the water cooled boxer engines.


This particular piece of equipment has as its function to distill-out any oil from the crankcase.  Using vacuum from the intake, crankcase gasses are pulled up and through a diaphragm which doesn’t allow droplets of oil to go through.  Any drops are redirected back to the main oil supply while the “dirty air” that makes it through the diaphragm is mixed with the intake air and gasoline to be burnt up in the combustion cycle.


Generally, when this piece deteriorates, a BIG, no, a HUMONGOUS cloud of white smoke is produced at startup.  In some cases a loud screeching (almost metallic) noise or whistle is produced by a tear in the diaphragm.

When any of these symptoms appear, quickly replace the air/oil separator.  Failure to do so may cause the engine to hydrolock from liquid oil in the cylinders which could get very expensive.

The life of this piece varies from a low of 40,000 miles to well over 100,000 miles.

It is not terribly expensive.  Somewhere around $100.00 for the part and a few hours labor to install.

Finally, suspension components are also wear items which should be routinely inspected, especially if the car is AX’d or tracked.

Pieces such as lower control arms, trailing arms, wishbone, connecting rods and swaybar droplinks have ball joints that will wear with mileage.

The first to go are usually the droplinks which can cause quite a rattle when driving over pavers or irregular pavement.

Most of these parts are difficult to diagnose because they cannot be inspected with the car loading the suspension, and even with the suspension unloaded it may still be difficult to obtain movement when the part is just slightly worn.

Shocks and struts tend to last a long time and when they fail the usual telltale sign is an oily seepage on the strut or shock.

The springs, on the other hand tend to settle a bit initially and then very slowly but continuously with time.

If your car is approaching or has passed the 100,000 mile mark I urge you to inspect these not-so-obvious pieces and have them replaced when necessary.

You will enjoy your Porsche much more if you do.

Pedro