Mk3 jetta and passat new owner/buyer's checklist (1996-1997 passat TDI, 1996-1999 jetta TDI)
back to 1000q: general TDI FAQ and how to index

Introduction

Congratulations!  You just bought a new car, or at least a car that's new to you.  Here is a list of common problems that should be checked and other basic maintenance items.  You can view a full list of how tos for the mk3 TDI at: 1000q: mk3 turbodiesel FAQ and "how to" index, this page is organized to show new owner info.

Mk3 means mark 3 or 3rd generation.  A3 is the 3rd generation jetta.  B4 is the passat.  Take a look through 1000q: jetta-passat differences to see what interchangeable parts or differences the mk3 jetta and passat have. 

You can also refer to 1000 answered questions: jetta specs or 1000q: passat specs to see the maintenance intervals for items such as the timing belt, coolant, oil, etc., and "how to" links.  Also read 1000q: proper engine break in for more details on why you should occasionally put the engine under high load/rpm.   

For immediate inspection

Timing belt = 60,000 mile replacement - this must be serviced immediately if there is no recent record of changing it.  If this part fails, the cylinder head will be damaged and in severe cases you will need a new engine.  This is because the TDI is an interference engine, meaning if the timing belt or timing belt roller/tensioner fails, the valves will hit the piston and cause damage.  Mk4 cars can use a long life timing belt, the Mk3 must stick to the 60,000 mile maximum replacement interval.  See 1000q: timing belt removal or check for more details.

Note - if you just purchased this car, many sellers will have the timing belt changed to add value to the car.  Many don't know how to properly index the tight tolerances that a diesel engine needs or the procedures for replacing the timing belt on a TDI or have a mechanic who is used to gasoline cars and then does the work on a TDI engine. At least remove the timing belt cover and inspect the parts to see if they look new as some sellers will outright lie.  If you have any doubt about the timing belt, have it changed as soon as possible not as soon as practical!

Engine oil = 10,000 mile change w/filter if you are using synthetic diesel engine oil.  See 1000q: diesel engine oil for a list of oils you can use in this TDI.  Note that it is normal for the oil to be black, even when new.  It is also normal for the engine to consume a little oil between engine oil changes.  See the engine oil list for more details.  

Plastic belly shield present? - While you are under the hood, see if the plastic belly pan is there, it's a black plastic shield that covers the bottom of the engine bay.  If you can see the ground through the engine bay, someone lost it.  It should be replaced to keep water and dirt off the bottom of the engine and belts.

Tire air pressure = as specified by the manufacturer.  There is a sticker inside the fuel door, on the inside of the driver's side door, or in the trunk which will specify an appropriate cold tire air pressure.  Check the pressure only when the tire is cool or you haven't driven the car in at least 5 hours.  A generic tire pressure you can use is 32 psi, never exceed the cold tire pressure listed on the side of the tire.

Engine coolant = lifetime coolant should be changed as necessary.  Note that VW/Audi G12 (G12+) or Pentosin coolant is red, pink, or purple.  Do not mix G12/G12+ or any VW compatible coolant with other colors (green, blue, orange) otherwise it will damage the coolant.  If it has to be topped off, use distilled water.  See 1000q: coolant flush to see a how to article on this.  Also note that the Jetta came with G12, some Passat came from the factory with blue colored G11 which is not compatible with G12/G12+.

Diesel fuel filter = 10,000 mile drain water, 20,000 mile replacement.  If you plan on using high percentages of biodiesel,  you should change it as soon as practical because biodiesel can loosen up deposits.   See 1000q: fuel filter change for more details.  See 1000q: intro to biodiesel for more info on biodiesel.

Diesel injection pump leaks - Due to age and fuel issues, the seals on the injection pump can leak.  The diesel fuel will corrode the timing belt and coolant hoses and even a small leak should be cleaned up asap.  The top cover, middle quantity adjuster section, and head o-ring can be replaced on the car, most of the other seals should ideally be done off the car and might need a rebuild with all new seals.  The pump should not be totally removed without locking the timing belt with VW timing belt tools.  See 1000q: injection pump top cover replacement for more details on top seal replacement.  Warning: only the top cover seal can be easily replaced, the other seals require a VAG-COM and/or at least basic mechanical sense.  See 1000q: injection pump removal for more details on removal.

Other notes/VW quirks: The ecu has a vacuum hose inside it that will need replacement, all mk3 VW TDI have this problem.  Even if it looks okay, replace it!  If you have a check engine light "65535 - Internal Control Module Memory Error" this is an indication that the hose or another vacuum hose is leaking.  Many bad ecu diagnosis can be solved by replacing this hose.  See 1000q: ecu hose replacement for this procedure.  The vacuum hose ends get dried out, rub through, or crack, causing running problems.  They are mostly 3.5mm and 4mm hoses, you can buy silicone hose at Mcmaster. 

Replace relay 109 Some cars have a relay 109 that can fail, leaving the car suddenly off without explanation.  Relay 109 controls the ECU and since the ECU controls fueling, no relay 109 causes the engine to suddenly shut off.   The old relay is black and marked "109" and is under the dashboard in the relay box.  The redesigned relay to fix this problem is gray and marked "109".  If you have a black relay 109, get it replaced ASAP with a gray relay 109.  A common symptom is the glow plug light not turning on.  Sometimes the relay will cool down, letting you start the car a few minutes after suddenly shutting off.  

If the engine ever suddenly gives a lot of throttle on its own, immediately shut off the ignition and do not start it.  You can also put it in 5th gear and apply brakes as necessary and as safe, so make sure you don't cause an accident slamming on the brakes!  Through an engine malfunction, diesel engines could have an engine runaway which will cause the engine to race higher on it's own and self-destruct.  Immediately shut off the ignition as is safe and practical and take it to a mechanic before starting it again.  Read more about diesel runaway at 1000q: turbocharging - runaway engine.

Service areas that can wait and common problems

The instrument cluster on the passat often burn out and need to be replaced.  Be very careful of a passat with low mileage because it was probably a replacement instrument cluster and does not reflect the true mileage.  If you take off some of the instrument panel trim, there is red paint on the original screws holding the instrument cluster.  If this is disturbed, the cluster may not be original.  The problem comes from cranking the engine with low battery, the voltage drop from using the starter discharges the memory in the dashboard, extended starting can cause permanent damage.  If you drain the battery down, do not try to start it without fully charging the battery!  If you play with the ignition key, hear a buzzing sound from the dashboard, and the trip meter resets to zero, this means that you are in the danger zone.  If you have a low battery, STOP and get it fully charged.

The door handles tend to stick or become hard to actuate with wear.  If the back doors open easily but the driver's side is hard, it can be easily adjusted.  See 1000q: passat jetta door handle adjustment/repair FAQ

Get a VAG-COM and scan the car for codes.  If you plan on doing your own work on this car, you need a VAG-COM.  This is a computer diagnostic cable and software specifically for VW/Audi,etc.

Apply the parking brake when parking!  It's good practice with any car but it is important on VWs because this sets the rear caliper self adjusters.  It's best to apply the brake before going into park (auto trans) or first/reverse gear (manual trans) to put stress on the brake instead of the transmission internals.

After scanning with a VAG-COM you may notice airbag error codes.  The Mk3 airbag sensors are sensitive and will often set off a false alarm code.  Clear the code and see if it comes back, it is very common due to overly sensitive sensors.  If the code comes back soon, there is probably a real problem.  Check the heater core for leaks, as it can leak coolant onto the electrical connectors below it and corrode the system.  Also note that the Mk4 cars had a problem with VAG-COM damaging the airbag controller, this does not apply to mk3 cars.

The car might go into limp mode due to a broken vacuum line or sticking solenoid.  If you are applying power and all of a sudden it feels like you hit a huge headwind and power is taken away, this is limp mode.  See 1000q: limp mode for some easy fixes.

The diesel fuel injection pump can have the fuel temperature sensor malfunction, if you go to the dealership, they will try to sell you a new injection pump.  It is user replaceable, see 1000q: fuel temperature sensor replacement for a detailed "how to" on fixing this.

Due to age and possibly the switch to ultra low sulfur fuel, some people experience leaking seals on the fuel injection pump (only for 1998-2003 models).  This will cause a no or hard start condition due to the fuel pump losing it's prime.  The dealership will not fix it, their only option is to replace the entire pump at great expense.  It's easy to change a few of the seals on the car as long as you have the right tools.

The center console HVAC light often burns out.  Just pull the center knob straight out to reveal the light bulb.

Misc VW quirks and maintenance, non priority

Holding the door key in "unlock" will open the power windows.  If this happens even when you're not holding it in unlock, the microswitch inside the door handle is faulty and is making the ignition switch think you are holding the key to unlock.  

It's common for the valve cover or EGR to seep oil.  None of these will affect engine function but it can cause smoke and a big oily mess.  The valve cover seal can be easily replaced but the EGR is part of the intake manifold and has to be replaced as one piece.

The power door locks are vacuum actuated.  Some Audis did this too because it moves the door locks smoothly instead of an electric solenoid thunking them up and down.  The problem is that a faulty door microswitch, vacuum leak due to a worn line in the door hinges, and other issues can cause problems.  See 1000q: central vacuum locking repair.

Stepping on the brake and accelerator at the same time will cause the drive by wire throttle to reduce power.  The Audi R8 exotic sports car also does it too, its a byproduct of drive by wire.

The mk3 TDI were usually sold in base trim, you probably did not have remote keyless entry.  See 1000q: adding OEM VW remote keyless entry for the procedure.

Get the car detailed.  You will be amazed at what a good paint polish and interior cleaning can do.  See 1000q: car detailing index for more tips.  

The front fenders will rust due to soundproofing that VW put between the metal fender and plastic wheel well liner.  You can prevent this from occurring by following the technique here or to view the TSB that VW released on the issue.  This is for the mk4 cars, but the mk3 cars can also have this problem.

Is there wax like tar dripping from the bottom of the doors?  It is the wax sealant that VW uses to prevent corrosion.  It helps to prevent rust but it melts, coming out of the door vents.  Just use Goo Gone or some other paint-safe solvent and wipe clean with a microfiber towel and lots of water.  Why microfiber instead of a paper towel?  Microfiber is non-scratch and paper towels will scratch the paint.  The tar also has lots of dirt stuck to it so using a microfiber towel will help avoid scratches.  Follow up with soap and water, then wax.  See 1000q: car detailing index for more detailing tips.

You may also notice that the headlight plastic is oxidized.  Polish the headlights and seal them as seen in 1000q: headlight polishing.

Brake and clutch fluid should be changed every 2 years with DOT 4 fluid.  See 1000q: brake / clutch fluid flush for some tips.

The exhaust gas recirculation (EGR) system lets in exhaust which mixes with the oily crankcase vapors.  It forms a carbon buildup which will clog the intake.  Once build up sticks to the intake, it should be removed from the car for cleaning or replacement, do NOT try to clean it while it's still attached to the engine.  See 1000q: intake cleaning for the procedure - note, procedure is for the mk4 car, mk3 is similar.  Note that many people suggest turning down the EGR with a VAG-COM, but the ECU will adapt and the confirmed result is lower fuel economy.  

The EGR can also leak oil out the outside of the valve.  This causes an oily mess but it can also be a fire hazard if the leak is bad and a lot of oil gets onto the exhaust.  Previous TDIs had the EGR and intake manifold as one piece, luckily the mk4 cars have the EGR and intake manifold as two separate pieces.  EGR replacement is suggested.  See the above paragraph for the removal procedure.

If you have a passat, you may have noticed a chirping noise on cold starts that gets worse on cold days.  Disabling the daytime running lights will help reduce this tendency but the only solution is to replace the harmonic balancer and maybe the serpentine belt tensioner.  If you have a jetta, the chirping noise could also be the one-way clutch on the alternator pulley slipping (not used on the passat).  The alternator pulley clutch is designed to increase the life of the alternator by letting it freewheel in one direction.

The parking brake cables may freeze the rear calipers in the "engaged" position in freezing moist weather.  If the rear wheels stick on cold freezing mornings, that is the most likely cause of the problem.  The boots crack due to age and let water in.

The 1996 passat should have a metal ECU case that was replaced under a recall.  If it has a black plastic case it needs to be replaced.  If the 5th fuel injector (only for emissions) has not been disabled (it doesn't work anyways, wastes fuel, and creates unnecessary smoke), fix it now.  I think it may also have been a recall item.  See 1000q: jetta vs passat differences and 1000q: 5th injector disable for more details and a "how to".

The ignition switch replacement should be done on all mk3 TDI.  It was an extended warranty item for the 1996-1997 jetta/passat but only for 8 years and 100,000 miles so the coverage is probably worthless now (worth it to ask the dealer for a discount anyways).  A bad ignition switch can cause the car to have flaky electrical symptoms, shut off the car, or result in a no/hard start.  If the car starts when you jiggle the key up, down, in, out, etc., while holding it to start, the ignition switch is causing the issue.

Do the front strut mounts have a lot of play between the mount and it's seat?  Does the strut top stick up and does the strut fall down a little when you raise the car?  This is normal because some play is needed to allow the front wheels to turn.  As the suspension ages, this gap may get larger.

Clean the engine air filter (for all) and change the cabin air filter (for passat only).  The snowscreen for the air intake should also be cleaned.  See that procedure at 1000q: intake air filter and snowscreen service.  

The passat center console glove box has a weak door hinge and tends to break.  It costs $75 for a replacement, available from worldimpex or the dealership.

It's normal for the speedometer to read slightly higher than actual speed.  German cars tend to have fast speedometers to account for car variations and so that they don't read lower than actual speed.  The odometer reading should be correct and is a separate display from the speedometer. 

These are all the most common areas that need attention with these cars, see 1000q: mk3 jetta-passat "how to" index for a more comprehensive list of  how tos.  If you know something that should be added to this list, please add your comment at the myturbodiesel.com forums, thank you!