Click here for complete engine specifications for all Cabriolet engines.
The engine code is located at the top of the engine block, at cylinder #3, just below the spark plug. The 6-
Cylinder Head Build Date
Click here for an explanation on deciphering the cylinder head build date stamp.
Transverse and Non-
Cabriolets have transversely-
Furthermore, these engines, in stock form, are known as non-
The right/left sides of a car are based upon you sitting in the car, facing the engine compartment. Therefore, the right side of the car = passenger side; the left side of the car = driver's side (those in RHD countries, the "driver's" and "passenger" sides would be reversed).
The firing order on all 4-
(If you happen to have swapped in a 9A engine, the firing order is still 1-
Rubber vs. poly: Rubber mounts are OEM and cushion, or isolate, the engine vibrations. Poly mounts are aftermarket and have a tendency to allow the engine vibrations to pass through to the chassis (i.e., you will feel the vibrations inside the car).
When motor mounts fail, the engine and transmission will rock causing very noticeable vibrations inside the passenger compartment (especially at idle), shifting issues, exhaust damage, and more.
Note: The following information applies only to the factory-
If your car has had an engine swap, please consult a manual or online references for
your particular engine for its oil requirements.
Viscosity: At right is an oil viscosity chart in relation to ambient air temperature. This chart
is an industry standard for modern oils with higher viscosity indices than oils from 40 years
ago; it does, however, closely match the original chart in the Cabriolet owner's manual.
Use the viscosity that matches your climate. If you're seeing slight drops in oil pressure,
try the next viscosity up from the one currently in use, but mind the temperature limits.
Do not drive at high speeds for extended periods with a 5Wxx oil if the ambient
temperature rises above the indicated limits. Engine damage may occur.
The most common viscosities used in the Cabriolet world: 10W40, 15W40, 20W50.
Yes, it is perfectly acceptable to mix viscosity grades.
20W50: Should you be using it? It all depends on your climate and your engine.
My '86, with 132,000 miles on the original engine, resides in the Arizona desert
that has an average summer temperature of 105°F, with spikes up to 120°F.
This car uses 20W50 to keep oil pressures nominal. Because the winter temps
only ocassionally dip down to the freezing level, and the engine is always warmed up for a couple of minutes before driving, 20W50 is not a problem. If you live in a place like South Dakota, 20W50 in the warm summer months may be fine; however, it will be too thick for the winter months (if you plan to drive the car in severe winter conditions, switch to a lower viscosity -
Type: Conventional, synthetic, or blend.
High mileage version: Use (if desired) if your engine has 100,000+ miles and/or is showing signs of age (a small drop in oil pressure, slight leaks, etc.). High mileage oils are formulated to care for aging engines, such as higher zinc content, conditioners to preserve seals, and viscosity modifiers to help retain the oil's thickness at higher temperatures.
API Service: SF and SG are the original API type for these cars. Those two types are now obsolete; use the current types of SJ, SL, SM, SN, or SN+.
Brand: Use your preferred brand, provided it's a top tier (Mobil1, Pennzoil, Castrol, Shell, Valvoline, etc.).
4.0L with filter change (fill the filter with oil before installing)
3.5L without filter change
Oil Viscosity Numbers Explained
Drain plug copper washer part #N0138492
Minimim oil pressure in Cabriolets is 2 bar at 2000 rpm with the oil temperature at 80°C.
Click here to read about the low oil pressure warning system in these cars.
1) Contrary to common belief, all oil filters listed above, including Fram, have anti-
2) Fram and Bosch (yes, Bosch) oil filters are not recommended due to their inferior build quality.
Click here for additional 1.8L dipstick information.
Fuel injected engines:
Oil on the air filter is commonly referred to as "compression blow-
It's wise to upgrade your 3-
Volkswagen part numbers:
026198025A (cork gasket; original; requires shouldered studs; alternate part #056198025A)
051103483A (rubber gasket; upgrade; requires shoulderless studs)
026198025C (rubber gasket & shoulderless stud retrofit kit; upgrade)
026103400A (shouldered stud; M6x25)
N10186301 (shoulderless stud; M6x20)
It's wise to upgrade your cork valve cover gasket to a rubber one. No gasket sealant is required and rubber gaskets are more leak-
Volkswagen part numbers:
028103609A (cork gasket; original)
044103609D (rubber gasket; upgrade)
N90008401 (M6x14 hex head bolt with shoulder; original used with cork gasket; 20-
N90592702 (M6x17 hex head bolt with shoulder; 20 required with rubber gasket upgrade)
Click here for belt diagrams and part numbers.
Finding Vacuum Leaks
Use a nonflammable carb cleaner and slowly spray the vacuum hoses/tubes one at a time while the engine is running at idle. When the engine stumbles, you've found the leak. If a leak is found, do yourself and the car a favor and replace all of the rubber vacuum lines... preventative maintenance! In addition to the vacuum lines, vacuum leaks can also occur at the following locations:
20" Hg at idle, manifold
0" Hg at idle, distributor
10" Hg above idle, manifold & distributor
How to use a vacuum gauge and what the gauge tells you
Pastic Tubes: Outside diameter is 4mm (VW part #N 020 139 1)
Rubber Hose: Inside diameter is 3mm (VW part #N 020 291 1)
Your local auto parts stores carry vacuum the above lines, albeit aftermarket versions.
Vacuum Line Diagrams
Description: Rapid, multiple knocks in rapid succession that have a high pitch; occurs only when the car is being driven at road speed and a sudden load is applied to the engine (extra fuel is sent to the pistons).
Common Remedy: Switch to premium fuel for 6 months; after 6 months, switch back. If the knock continues, see your mechanic; head work will need to be performed.
Description: Deeper, slower, more rhythmic sound than pre-
Common Remedy: Do not drive the car if this sound is heard! Have the car towed to your favorite repair shop.
Description: Lighter sound than a knock, but also varies with engine RPM; can be heard at idle.
Common Remedy: Sometimes debris frees itself and is flushed into the oil filter; replace the oil and filter. If this doesn't solve the problem, one or more lifters will need replacing.
Squeak, squeal, chirp
Common Remedy: Replace worn belts; tighten loose belts; realign slipped belts. Replace belt tensioners. Replace/realign belt pullies.
Description: A deep, rhythmic groan or growl.
Common Remedy: Replace the water pump (and thermostat and coolant while you're at it).
Early Warning Signs
*The temperature will jump to "hot" when a pocket of super-
If early warning signs are leading you to suspect impending head gasket failure, have a repair shop conduct tests (or do the DIY test below) on the cooling system to verify possible head gasket failure (they'll check, in part, to see if combustion gasses are leaking into the cooling system which cause the system to over-
DIY test: With the engine cold, attach a latex glove to the coolant expansion tank fill hole (early Cabriolets will use the radiator fill hole). Leave the cap off and run the engine for a minute. If the glove inflates, you've most likely got a leaking/blown head gasket (have a professional verify your findings).
If the spark plugs are continuously getting fouled, chances are that oil is leaking into the cylinders, which indicates possible piston ring and/or valve stem wear.
Only Cabriolets equipped with Digifant I engines have the OBD I diagnostic port and check engine light. Furthermore, an OBD II diagnostic tool cannot be used to pull fault codes from an OBD I system unless it has an adapter and the capability to connect to and pull codes from an OBD I system!
The check engine light usually means that there is a fault in the emissions system. Click here for how to pull fault codes, a list of fault codes, and ECU resetting.
Cruise Control Does Not Work
Check for vacuum leaks. If the system still does not operate, use this procedure.
Cruise Control Vacuum Diagram
*Autotech products are another option. Click here for further discussion.
Scientific Rabbit is another source for ported intake manifolds and larger intake air boxes.
Electronic upgrades (Digifant)
Install an Advanced Motorsport performance chip. K-
You can add a cold-
Intake air temperature (IAT) sensors
This question is often asked by those who have bought, or are looking to buy, a so-
A clean engine is a happy engine! Why? A dirty engine generally runs hotter than a clean one. Therefore, keeping your engine bay and the engine itself clean should be part of your regular maintenance. Additionally, keeping the underside of the hood tidy allows for quicker, easier leak detection (and your mechanics appreciate working on a clean engine!). With a little work, your engine can look this clean.
If you don't want it professionally cleaned up, you can do it yourself. Using a combination of a steamer, a degreaser such as Simple Green® or Totally Awesome (latter available at 99¢ Stores) and a high-
Speaking of ovens: It's advised by professional detailers to not use oven cleaner to rid the engine of caked-