Pre-purchase Inspections 101

tech forum

BY TONY CALLAS & TOM PRINE

oday, as throughout Porsche's history,

when a new Porsche passes its final

inspections and leaves the factory, it meets

a quality standard that is among the high-

est in the world. Once sold, the first owner

and all that subsequently follow become

the responsible caretakers of these extraor-

dinary and complex machines.

Some Porsche owners maintain their

cars to the highest standards to preserve

their aesthetic and mechanical condition.

Others may extend out services and accept

a higher degree of wear and tear. There are

also those who cannot truly afford the car

and allow it to fall into disrepair. Over

years of operation, each Porsche develops

a unique history based on use, mainte-

nance, repair, modifications, and/or acci-

dents. What all of these cars have in com-

mon is that, at some point in time, each

will be offered for sale.

As a prospective Porsche buyer, you

should consider that any pre-owned Por-

sche has the potential for significant cost

to you beyond its purchase price. Any car

can have problems, disclosed or not.

Having the right questions in mind can go

a long way toward protecting you from

nasty surprises. How did the owner — and

any previous owner(s) — maintain the

car? Was it properly serviced? Were high-

quality parts and correct mechanical and

accident repair practices utilized? Were

corners cut to save money?

If you're looking for a popular but rare

model, a specific exterior color, or a partic-

ular group of options, you may find your

dream car is located far away, in another

state. If you buy on emotion, you might find

yourself in a situation where you're paying

big repair bills to correct previous neglect,

abuse, substandard workmanship, and/or

collateral damage. A better solution: Make

your purchase contingent on the car pass-

ing a comprehensive pre-purchase inspec-

tion, commonly referred to as a

"PPI."

A comprehensive PPI is a process some-

what like that of a forensic investigation,

where experience and technology are uti-

lized to investigate and establish facts. The

PPI should be performed at a professional

Porsche repair facility, and conducted by

a technician who is highly experienced

with the year and model you are looking

at. Through an in-shop evaluation and

extended test drive, a technician collects

and documents empirical data on all areas

and systems of the car.

These areas may include perform-

ance, mechanicals, chassis/body/paint,

safety systems, and electronic and elec-

trical equipment/systems. A compression

and leak-down test of each cylinder is

needed to indicate the mechanical con-

dition of the engine.

For

computer-con-

trolled cars, the PPI should also include

a complete electronic interrogation of

the onboard computers to confirm the

car's operating history and the presence

of any system faults at the time of the

PPI. Sometimes, additional diagnostic

time is needed for specific problems,

such as unusual running issues, elec-

tronic faults, oil leaks, etc.

A PPI may even reveal things about a

car that the owner/dealer doesn't know or

is trying to hide. If the price can be estab-

lished for the work needed to rectify any

problems, these findings can sometimes

be utilized to negotiate a lower selling

price. That said, if you have already nego-

tiated the price with the seller, he or she

may or may not be willing to go down fur-

ther on price regardless of the issues.

Sellers, whether private parties or deal-

ers, will discuss price — but they know

that there's always another buyer out there

who may be impulsive and buy the same

car without asking for the PPI.

In this

Tech Forum,

we'll take

general

look at buying a used Porsche and more

specifically at the Pre-purchase Inspection,

what it is, and how it can save you far more

money than it costs.

The Porsche hood crest—and the hood itself—can be damaged when pressure

is applied to the emblem to close the hood.

DECEMBER 2012

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Pre-PPI advice

Prior to even getting to the PPI, you

should consider a few things to ensure that

the car being looked into is worthy of your

pursuit — including your investment of

time and money. Give some thought to

what Porsche model really interests you.

That may sound somewhat odd, but for a

first-time Porsche buyer or even a current

owner, it is well worth taking the time to

test-drive different models to help you

decide what you really like.

Understand that Porsches are expensive

to maintain. Porsche has always produced

well-balanced, high-performance cars uti-

lizing quality components and workman-

ship throughout. That said, as the miles

add up, standard maintenance items will

be needed. Tires, brakes, hoses, belts,

struts/shocks, clutch, fluid changes and/or

flushes, minor and major services, and

other repairs all add up. Be prepared to set

aside a minimum of $2,000-3,000 per year

for maintenance. You may not spend this

full amount each year, but in the long run

it will balance out. This is something first-

time Porsche buyers often underestimate.

Do your due diligence; learn as much

as you can about the model(s) you are

pursuing. Any car can have an unexpected

breakdown, but be sure you understand

any underlying issue you may face and

how to avoid those potential problems.

There are many sources of information

available online and, of course, here in the

pages of

Excellence.

You can also

utilize

the

knowledge of your local Porsche repair

facility; generate a list of questions and

make an appointment to meet with the

staff and let them address your concerns.

When you find a car that interests you,

do not get emotional. Instead, look at the

car as if you were checking it out for your

best friend. Be discriminating. If there are

obvious problems, there may be more

lurking that you cannot see. The goal here

is to find a good car, not to become a pro-

fessional PPI customer and have car after

car inspected. Everyone wants a bargain,

which most people equate to an inexpen-

sive purchase price. However, in the world

of Porsche ownership, you are far better

off buying a car in exceptional condition

and maintaining it that way. Be prepared

to walk away from a car if it suffers from

neglect. You can fix many things about a

car, but, in these cases, bigger and more

expensive issues can be waiting.

Ask the seller to let you review the fac-

tory maintenance book and repair receipts

going back to when the car was new. These

records validate the car's service and repair

history, thus giving you the proof of when

and where the work was performed. Of

Top: The Cabriolet top, over time and expo-

sure

to the elements, can develop dry rot

and separate. There is no "repair," except

to install an expensive replacement top.

Middle: The numbering seen on this tire is

its

manufacture date; "5204" indicates the

52nd week of 2004.

Bottom: When old tires are dried out and

cracked, they should be replaced ASAP.

course, some owners may remove selective

receipts regarding items deemed to be

embarrassing or problematic.

If the owner has only a few receipts or

none at all, this should be viewed as a neg-

ative. It does not necessarily mean the car

is bad, however seeing and having this

documentation is an important data point

to you as a prospective buyer. The owner's

memory and stories are not good enough;

there will be a day when you too will be

selling the car, and having the full records

makes your car more desirable and poten-

tially valuable to a selective buyer.

A stamped and dated factory mainte-

nance book can provide some basic infor-

mation, but these are usually filled in only

if the owner requests it. Services like Car-

Fax

can

be a source of information —

especially accident history — but data on

service and repairs can be sketchy depend-

ing on where the car was serviced.

You can also contact Porsche Cars

North America at 1(800) PORSCHE. You

will need to provide the complete Vehicle

Identification Number (VIN). If the car

was dealer-serviced they should be able to

direct you to that dealer. Keep in mind, a

Porsche dealer or independent repair facil-

ity will not disclose a previous owner's

personal information — but they may be

willing to verbally discuss with you the

details of the work they performed.

A PPI may uncover maintenance or

repair issues that should be addressed

soon after purchasing the car. Be prepared

to invest a few thousand dollars or more

to bring the services current and make any

repairs that have the potential of getting

worse or causing collateral damage to

other components or systems.

Setting up a PPI

is best to find and contact the shop

you want to perform the PPI a few days

prior to when you need the work com-

pleted. If the car you are considering is

outside your local area, out of state, or

cross-country, you should enlist the help

of your local or national Porsche club to

assist you in finding a well-known and

well-recommended repair facility.

Not all repair facilities will perform a

PPI; this is generally due to the potential

for liability should they make a mistake

and/or the disruption of their customer

scheduling. Most repair facilities can

appreciate that the

PPI

can be time-sen-

sitive and will usually work you into their

schedule as soon as possible.

The Porsche repair facility you hire to

perform a PPI should not be the same

company where the seller normally does

business. Even if this facility is conve-

niently located to the seller, it may not be

in your best interest. While there may be

no issue of impropriety, you should have

fresh eyes doing this work.

Call and discuss what the shop nor-

mally inspects during a PPI and, if this di

fers from your needs, explain what areas

you want them to focus on. If you cannot

be present during the PPI, it is very impor-

tant that you inform the repair facility of

anything that is a "deal killer" for you —

noting that the PPI should be stopped ti

such a problem is encountered. Our expe-

rience with some buyers' "deal killer" con-

ditions include partially or fully repainted

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bodywork, accident damage, non-original

engine, internal engine damage, and an

excessive amount of metal in the oil filter,

just to name a few.

Additionally, the repair facility should

stop and contact you if any serious or ex-

pensive problems are discovered during

the PPI — even if they're not on your list.

Why ask the shop to spend more time if it

finds a glaring problem right away? Ask if

photos will be taken during the PPI and

forwarded to you, as this can be very help-

ful. Also, schedule your PPI on a day when

you can be easily reached — no important

meetings or airline travel.

The information obtained in the PPI

should be provided only to the person

who ordered it, which is usually the poten-

tial buyer. If you, as the potential buyer,

choose to share the information with the

seller, that is your prerogative — you paid

for the work and information. Your feel-

ings on this should be expressed to the

repair facility doing the PPI.

The buyer normally fmali7es the logis-

tics of the PPI. If the seller is dropping the

car off and needs a rental car, or if the car

must be towed to and from the inspection,

the prospective buyer normally pays for

this. Dealers will usually have their sales-

person or a lot porter drop off and pick up

the car at the inspecting repair facility.

The cost of a PPI will vary based on the

time spent and the hourly labor rate of the

repair facility plus any parts (oil filter,

spark plugs, gearbox oil, etc.) replaced

during the PPI. A basic safety inspection

can be done in a half hour, while a com-

prehensive PPI can take six to twelve

hours. Standards differ according to buy-

ers, shops, budgets, and cars. A 996/997

Turbo, for instance, requires that the rear

bumper and intercoolers be removed to

perform the compression and leak-down

tests — thus putting these models at the

high end of the PPI price range.

The PPI begins

When a car arrives, it is usually checked

in and the buyer is contacted (if not pres-

ent) and informed that the PPI is com-

mencing. An initial visual check is done,

which will note any aesthetic issues with

the exterior or interior. This can include

dings, dents, scratches, and scrapes in the

bodywork, noticeable paint chips, interior

wear or damage, windshield or other glass

damage, cracked plastic lenses, and wheel

finish issues like curb rash. This is not the

detailed body/chassis inspection, which

will take place later.

The first order of business is to start the

engine to check to see if any exhaust

Top: The cost to repair body/paint damage

often exceeds expectations. A full, quality

repaint will cost you north of $15,000.

Middle: This wheel was repainted improp-

erly; the paint on the valve stem indicates

the wheel was touched up to hide flaws.

Bottom: When a 911, especially a wide-

body car, is hit from behind, rear wheel

arches often bend and are hard to repair.

smoke is present. If so, how much and

does it appear to be oil-based — or is the

engine running excessively rich? It should

be noted if the engine is cold or at operat-

ing temperature when started. On 986/996

or 987/997 models, oil smoke could be

caused by an air-oil separator issue. It can

also be a valve guide issue, which would be

suspect on most air-cooled engines.

The engine's oil level is checked next. If

the engine is at operating temperature, this

is done prior to the test drive or following

the test drive if the engine is cold. Any air-

cooled 911 engine has a dry sump oiling

system that utilizes a dipstick with mini-

mum and maximum marks. The oil level

should be in the middle between these two

marks at operating temperature at idle.

Water-cooled engines should have the oil

level at the identified maximum mark.

If the oil level is low, this in itself does

not identify that the engine has an oil con-

sumption issue — but it is a data point

and will be considered with other infor-

mation obtained during the PPI. Some-

times it is found that the oil level has been

overfilled, which can be a serious situation

if oil is getting into the intake system.

Prior to the test drive, tire pressures are

checked and corrected if needed — after

being noted.

The test drive

Some shops like to have two techni-

cians in the car for the test drive. The pri-

mary tech responsible for the PPI is in the

driver's seat, and a second tech rides along

as an observer and to take notes. Any item

or function that doesn't appear to be cor-

rect will be noted.

At the beginning of the test drive, the

vehicle's mileage is noted. The speedome-

ter, odometer, and trip odometer opera-

tion will be checked during the test drive.

The distance the car will be driven may

vary and may be extended if an anomaly

is identified — but, normally, the car will

be driven about four to six miles once it is

at full operating temperature.

The ignition key is first turned to the on

position, but the engine is not started. All

instrument cluster warning lights should

illuminate. Once the engine is started, the

instrument cluster is again scanned, this

time for any warning lights that remain

illuminated. Cars equipped with a central

information display (986/996 and later=

should have all screen fields reviewed and

any warning or irregularities noted.

All electric windows are operated and

checked for failed or slow motors, bind-

ing, and broken switches. Seat heaters, if

present, should be turned on, and all man-

ual and electric articulation functions of

the seats will be tested. The exterior elec-

tric mirrors are operated in all directions

and then set to the driver's preference. The

interior rearview mirror is also checked for

attachment. Its ball cup adjusting socket

should be tight and the day/night (anti-

glare) toggle switch should be operational.

As the test drive begins, the air-condi-

tioning is turned on to high with air recir-

culation activated. A thermometer is then

placed in the center vent. It is noted how

quickly and how cold the A/C gets. As the

air temperature reaches its coldest point.

all fan speeds are checked. Depending on

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the ambient temperature and humidity

level, vent temperatures should drop to or

below 45° F on 964-and-later Porsches

with a healthy A/C system. The A/C is then

turned off and the heater is turned to full

heat. The transition from cold to hot

should be fast and become uncomfortable;

with heat coming from the footwell, dash

vents, and windshield defroster vents.

The audio system is activated next,

with all audio controls (balance, fader,

tone, and volume) checked for operation

and any noisy (scratchy) controls. Audio

distortion or rattles from the speakers at

reasonably high volume settings are

noted. AM and FM bands and other

audio sources such as cassette, CD, CD

changer, and iPod operation are checked

if present. If the car is equipped with a

navigation system, it is activated and set

for a return trip to the Porsche repair

facility. If the system is CD-based, the

presence of the CDs are verified.

When the car is in motion, any unusual

noise, rattle, or vibration is noted along

with the generalized area or source of the

anomaly. A tire balance issue can be fairly

common, as some owners do not rebal-

ance or rotate tires as they wear. However,

worn control-arm bushings can also cause

a vibration that could be mistaken as a

tire-balance issue. Rattles and other noises

are usually linked to loose fasteners. Varied

types of road surfaces and driving speeds

can sometimes bring out surface-activated

wheel-balance issues — though the prob-

lem may not reveal itself during the drive

if it is intermittent.

Testing the performance of the car by

someone very familiar with how it should

operate is critical to the PPI process. The

goal is to make sure that the suspension,

tires, powertrain, and brake systems are all

performing at a level consistent with their

design intent. This can be achieved within

speeds of normal day-to-day driving.

Power delivery from the engine during

full-throttle acceleration should be con-

stant and without surging. In most Por-

sche models, first-gear acceleration is dra-

matic and quick thanks to the transaxle's

extremely low first-gear ratio multiplied

by the final-drive ratio, thus allowing a

not-so-great running engine to impress

with seemingly good power. Applying full

throttle at around 3000 rpm while in sec-

Top: A badly bent 993 steering tie rod is

usually caused by an improper tie-down

location when the car is being towed.

Bottom: A broken 993 heater air duct.

Normal thermal cycling and aging com-

monly cause this problem.

and or third gear will place a higher load

demand on the engine, thus making it rely

on its torque curve and work harder to

pull the load. If a running issue is present,

it should be discovered under these con-

ditions. The engine will likely be down on

power and/or have an inconsistent power

delivery with surging and possible smoke

from the exhaust.

Additionally, during full-throttle test-

ing at high rpm, the throttle should be

abruptly closed. Deceleration and high

cylinder vacuum result, which can also

trigger exhaust smoke usually caused by

worn valve guides, faulty valve stem seals,

and/or an air-oil separator issue. Often, a

seller will suggest that the car just needs to

be driven some; a technician should say

the problem needs to be diagnosed.

The gearbox should shift smoothly,

with no binding in the linkage and no

drama of any kind. Any difficulty or prob-

lems with shifting or noise should be diag-

nosed, as this is not normal. The clutch

should operate smoothly; any chatter or

slipping indicates a worn clutch that needs

replacement. If excessive pressure is needed

to depress the clutch pedal, this can be a

sign that the clutch disc is worn and/or

that there is a broken clutch pedal power

(helper) spring in the pedal assembly. Any

problems should be diagnosed.

Tiptronic transmissions normally work

flawlessly. If there is a long pause between

placing the shift lever into gear and feel-

ing the transmission react — or any slip-

ping, surging, or vibration — the problem

should be diagnosed. Lack of servicing is

the.biggest problem for Porsche's Tip-

tronic transmissions, causing abnormal

wear and possible early failures. Remem-

ber those service records?

The suspension system should feel firm

and react immediately to steering input

and/or road-surface irregularities. There

should be no vibrations, rattles, or bangs

when a dip, pothole, or bump is encoun-

tered. Handling should be great with any

Porsche, though it goes without saying

that these parts do wear over time and

mileage. Tires are a critical component to

handling and will be checked in detail dur-

ing the in-shop inspection.

Brakes are important to the perform-

ance of any car, and Porsche brakes are

amazing. The brakes should be tested to

ensure the car stops straight, with no

spongy pedal. If the car is equipped with

anti-lock brakes (ABS), the pulsation of

the system can be felt during its operation_

Multiple stops should be performed so the

brakes get hot enough to determine if any

issues are present.

Once back at the Porsche repair facility.

the test driver should review his or her list

of observations. Any concerns or poten-

tial issues should be highlighted to discuss

with the customer before diagnosing fur-

ther. After that, it's time to roll the car into

the shop for the second phase of the PP!.

which we'll explore in our next issue. In

the meantime, enjoy your Porsche.

•

Some technical information used in this

article is copyrighted by and used with per-

mission from Porsche Cars North America. At

photos by Tom Prine except where noted.

Have a technical question?

Email us at:

[email protected]

Sellers know that there's always another buyer out there who may

buy the same car without asking for a pre-purchase inspection.

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