If you own a car with a turbocharger, you might experience car turbo problems with it from time to time. In most cases, they are easy to diagnose and fix, but sometimes they can be a bit more tricky. Let me tell you about a recent case we had with a VW Transporter T5 that gave us a bit of a headache.
The VW Transporter T5 in question was fitted with a 2-liter bi-turbo engine and had gone into limp mode with the check engine light on. After using ODIS, we were able to identify an under-boost problem. This meant we had to start with a basic check of all the components that make the turbo work.
How We Fixed The Turbocharger
We started with the vacuum pipes and the actuators, and everything seemed okay. The boost pressure sensors were also checked and there were no issues. We then performed a smoke test where we filled the supply pipes from the air filter through the intercooler to the turbo, and thankfully, no leaks were detected.
With all external components seemingly in order, it was time to remove the turbo for a closer inspection. However, because it was a bi-turbo, it was quite large as it essentially had two turbos in one unit. But fortunately, there was enough room around the engine of a T5 to allow us to remove the necessary components. We removed the pipes, vacuum hoses, the DPF, the offside driveshaft, and rear engine mount before squeezing the turbo past the subframe and out.
Upon initial inspection, we couldn’t see any signs of breakage or play in the compressor wheel. However, we could only see one of the turbos, so we had to strip the unit to check the other one. Unfortunately, this required expensive tooling that we didn’t have, so we sent the unit to a local specialist for a closer look.
After stripping the unit, it was discovered that the turbine wheel hidden inside had sheered off, causing our under-boost problem. We then had to rebuild the turbo with new internals before re-fitting it to the vehicle.
How We Fixed The Turbocharger
We started with the vacuum pipes and the actuators, and everything seemed okay. The boost pressure sensors were also checked and there were no issues. We then performed a smoke test where we filled the supply pipes from the air filter through the intercooler to the turbo, and thankfully, no leaks were detected.
With all external components seemingly in order, it was time to remove the turbo for a closer inspection. However, because it was a bi-turbo, it was quite large as it essentially had two turbos in one unit. But fortunately, there was enough room around the engine of a T5 to allow us to remove the necessary components. We removed the pipes, vacuum hoses, the DPF, the offside driveshaft, and rear engine mount before squeezing the turbo past the subframe and out.
Upon initial inspection, we couldn’t see any signs of breakage or play in the compressor wheel. However, we could only see one of the turbos, so we had to strip the unit to check the other one. Unfortunately, this required expensive tooling that we didn’t have, so we sent the unit to a local specialist for a closer look.
After stripping the unit, it was discovered that the turbine wheel hidden inside had sheered off, causing our under-boost problem. We then had to rebuild the turbo with new internals before re-fitting it to the vehicle.
Turbo Repair or Replacement: Which Option Was Best for This Car?
The cost of the rebuild was several hundred pounds, but it was important to establish the cause of the problem, and it was still cheaper than purchasing a replacement turbo.
In conclusion, turbo problems can be a bit tricky to diagnose and fix, especially if you have a bi-turbo like the VW Transporter T5. However, by doing a thorough check of all the components that make the turbo work, you can narrow down the issue and get to the bottom of the problem. And if you do encounter a problem with your turbo, it’s important to address it sooner rather than later to prevent further damage to your engine.
