Common Problems With VW's 1.8T Engine (According To Owners)
Regardless of whether you drive one of the most reliable Toyota models ever made, or something laughably unreliable, every car will have a certain set of common problems which are worth looking out for. It's worth being aware of what the common problems with your car are, especially if you drive an older model, as problems are naturally more likely to arise with an engine that's done higher mileage, and one that has simply been working for a longer amount of time.
The engine under the spotlight here is Volkswagen's 1.8-liter turbocharged inline-four, a beloved powerplant which motivates a wide variety of models, from the iconic TT, through to the retro New Beetle.
While it's been years since the 1.8T engine has been sold under the hood of a new model, there are plenty of older models still proudly propelled by the boosted inline-four, which was sold in numerous power outputs, depending on which model it was destined for. In order to understand what goes wrong, why, and how to combat it, we've scoured the internet to find what owners have got to say about the engine.
Volkswagen's 1.8T engine suffers from only a few common problems
After perusing multiple owner's forums, one particular problem with the 1.8T engine keeps arising, and it's the pesky PCV system. PCV stands for Positive Crankcase Ventilation, and it helps gases from the engine's crankcase escape, which aids emissions. A faulty PCV system can lead to rough running, a lump idle, misfires, and an illuminated engine light. Fortunately, not only can you replace the PCV valve yourself, but the whole system itself is easily repaired, deleted, or replaced with an aftermarket kit.
Another issue, and one which can have dire consequences, is that the oil pick-up pipe gets filled with sludge, and therefore restricts the flow of oil to the engine. This is why many owners recommend using the correct, fully synthetic oil when performing services, and that services should be carried out regularly.
A third issue which owners report is that the factory water pump can be troublesome. The issues stem from the factory: The impellers are made of plastic, and struggle to manage the task at hand, ultimately leading to their failure. Changing this for an uprated unit with metal impellers is advised, and will help ensure future reliability.
The VW 1.8T engine can achieve huge mileages if cared for appropriately
The above common faults should provide any new or current owner with a high-priority list of jobs to tackle, in order to ensure ongoing reliability. If, in addition to regular maintenance, those jobs are taken care of, there is no reason why any 1.8T-powered VAG model cannot achieve impressive mileages. A number of Reddit users have boasted about mileages achieved in their 1.8T-powered models, with some stating "got 338k on my 1.8T from 2003 and it's running fine", and "I'm currently driving an 03 Passat with the 1.8T and it has 279k miles. Shows no signs of stopping".
What's more, the 1.8 turbo Audi/VW engine is great for tuning, whether you're simply looking to liven it up a little with a simple chip tune, or chase big power figures with an uprated turbo kit. However, neglecting basic maintenance tasks will only put a dampener on the ownership experience, whether the car is modified or not, so be sure to address the basics before seeking more power from the 1.8T engine.