The new common-rail TDI models do great in cold weather outside of one potentially serious problem – intercooler icing. Ice in the intercooler blocks airflow and, in the worst cases, can send ice chunks or liquid water into the engine, causing serious internal damage.
Why does this happen?
Part of the advanced emissions systems recycles exhaust gases into the intake. There are two sections of this – a high pressure system that recycles the exhaust directly into the pressurized air and a low pressure system that puts exhaust gases into the intake before the turbocharger.
The second system is the problem. Hot exhaust gases are pressurized pushed through the intercooler, which isn’t normally a problem until the temperature drops to below freezing. Then, the core of the intercooler is so cold that it causes condensation inside the intercooler itself. This becomes a problem when, after parking the car, this condensation turns to ice.
When does this happen?
This typically happens when the car is driven in sub-zero temperatures when the condensation collects. The problem doesn’t appear until you restart the car.
What are the symptoms of this problem?
Upon first starting the car in the morning, cars with icing in the intercooler will run more roughly than usual, sometimes will shake or sound like the motor is struggling to stay running. When icing becomes serious the motor may abruptly stall or make a rough “hiccup” or “missing” type noise.
What are the potential solutions?
Keeping the intercooler warm in the winter should prevent condensation from collecting in the first place. By blocking the extremely cold air, the intercooler should stay warm enough so that condensation does not build up.
We use the IDParts Winter Front on our own cars. We have two test vehicles that have had ice and moisture buildup in past winters. However, the symptoms disappeared once we installed the winter front.