This basic power plant was a no frills machine. It was based on an earlier VW engine that was at one time shared with Audi. The Mark IV series incorporates crank triggered ignition, i.e.; there is no distributor. The first few years, some engines used excess amounts of oil. The 2.0 engine is the last of the line of 4 cylinder motors loosely based on the original Rabbit engine from the 70’s. A cross flow head had been added for the Mark III cars, and the Mark IV version got a few more changes. Cross flow meaning that the intake goes in the front, and the exhaust comes out the back, improving breathing. Some of the changes went problematic. Some of those changes include crank triggered ignition, a relocated water pump, and a secondary air injection system.
Crankshaft Position Sensor Failure
The 2.0 engine got a crank triggered ignition system, consisting of a crankshaft position sensor and a camshaft position sensor. The intermediate shaft of the previous engine was deleted, and the ignition coil now occupies the engine block space where the distributor had been. Occasionally, we find a mystery crankshaft position sensor failure that either produces a momentary power loss, or breaks you down completely without leaving any code or evidence. If you momentarily lost power, or could not start once or twice, there may be no diagnostic trouble code. And the crank sensor may be the culprit. If the engine is dead, dead, dead, then there is almost always a code. And the crank sensor may be the culprit. This situation happens with some other engines as well.
Mark IV 2.0 Engine Oil Consumption: 99.5 through 2001
At first, we just noticed so many of the 2.0 engine cars showing up with no oil on the dipstick. In short order, we found that pretty much most of the engines in this model year range were chewing through a few quarts between oil changes. We have always had a policy of checking the engine oil level on every car on every visit, but that was not enough. The skinny soon surfaced through channels that VW had installed defective oil control rings in a large number of this series of 2.0 engines. Karmakanix advice helped a number of customers get their 2.0 engine repaired at the dealer while it was still under factory warranty. And we have done maybe a dozen of those piston ring jobs ourselves since then. These days, the cars may not be worth the $1600 job. But some engines foul spark plugs, destroy catalytic converters and won’t pass smog. We just tend to catch the issue early and install higher heat range spark plugs to counter the issue. And we advise those customers to keep track, and keep the oil full to avoid major engine damage. We can set up Bimonthly email reminders to check your oil, by sending emails through DemandForce. This problem with this 2.0 engine could be why future cars got oil level sensors that turn on an indicator light on the dash before the level went low enough to damage the engine. Perhaps not, since more oil eating engines were in a few of the future cars.
Secondary Air Injection: Passing Smog
As these 2.0 engines get older, more and more are failing smog. A common reason is failure of the secondary air injection system, or SAI. Most of time we find just a broken vacuum hose or a blown fuse. Sometimes on the 2.0 engines, we find the air passageways inside the exhaust manifold are clogged solid. This can occur either from the carbon that results from a life of low quality gasoline, or from residue left behind from an oil consumption issue.