Car Turbo Problems: How We Got to the Bottom of a Difficult Case with a VW Transporter T5

Car Turbo Problems: How We Got to the Bottom of a Difficult Case with a VW Transporter T5

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.

Car Turbo Problems
Seat Timing Chain

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.

Seat Timing Chain

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.

Car Turbo Problems
Car Engine Change

Car Engine Change

Timing Belt Replacement

The engine timing belt is a serviceable item that in most cases requires replacement every 5 years or at a specified mileage depending on the engine. If the timing belt, or the components associated with it were to fail the damage to the engine would be catastrophic and often leads to a car engine change. The last time we saw this was recently, the vehicle, a 2015 VW Golf 1.6tdi, was recovered in with obvious timing belt failure.

Seat Timing Chain

Car Engine Change

A reconditioned engine was purchased (almost half the price of a brand new unit), then the laborious task of fitting it could begin. First the exhaust and subframe were removed, then after disconnecting the wiring harness, driveshafts, clutch slave cylinder, gear cables, fuel and coolant hoses, the complete engine (with gearbox) was lowered to the floor.

The damage to timing belt, idlers, tensioner and coolant pump was extensive and therefore it was not possible to determine which component had failed first.

The new engine was bare, so everything including, the gearbox, flywheel, clutch, DPF (diesel particulate filter), turbocharger, EGR (exhaust gas recirculation) valve, injectors, sensors, coolant pipes, fuel lines, wiring and more had to be removed and then re-fitted to the new engine. This took a couple of days as every removed component had to checked and fitted in the correct order

using new gaskets and seals.

Seat Timing Chain

Removed Car Engine Parts

Once this was done the complete engine and gearbox was re-fitted into the vehicle and reconnected. All the other removed parts were installed before fresh oil and coolant was added. Next ODIS (Offboard Diagnostic Information System) was connected to tell the ECU that a new engine had been fitted and to reset the learnt parameters. A road test and re check for leaks was satisfactory and the customer was happy the have his car back, albeit after a hefty bill.

Seat Timing Chain

Do Timing Chains Need To Be Replaced?

Do Timing Chains Need To Be Replaced?

Not so long ago we had to diagnose a 2010 Seat Leon 1.2 because it was running poorly at idle speed and had an engine warning light illuminated on the dashboard. The fault stored was an exhaust oxygen sensor fault, however, we also noticed the engine sounded a little noisy.

We suspected that the timing chain could be worn therefore resulting in the engine timing being out, not burning all of the fuel, causing the oxygen sensor fault and making the engine idle erratic. Testing our theory was straightforward, we screw a crankshaft timing tool into the rear of the engine block, turn the engine over until the crankshaft meets the tool, and then fit a camshaft timing tool into the rear of the cylinder head.

As suspected the camshaft tool wouldn’t fit into position due to the stretch of the chain and proving that the timing was no longer correct. A new chain, sprockets, and tensioner would be required to rectify the fault. Once the timing tools are fitted and holding the crankshaft and camshaft in the position we removed the bottom pulley, timing chain cover and sump to gain access to the chain.

Next, we removed the tensioner, chain, guides and sprockets and replaced them with new parts. The locking tools were removed so that we could rotate the engine a couple of times before making sure that we could re-fitted them easily and therefore confirm that the timing was correct. This was satisfactory so we refitted the timing chain covers and sump before replacing the oil filter and filling it with new oil.

Finally, we had to connect ODIS (Offboard diagnostic information system) to tell the vehicle that a new chain had been fitted, reset any learnt parameters and clear previous fault codes. On start-up, the engine was noticeably quieter and idling smoothly. A road test and final check ensured the oxygen sensor faults did not return and everything was working perfectly.

Car Engine timing belt
Engine Tuning & ECU Remapping in Sussex

Engine Tuning & ECU Remapping in Sussex

Tuning or re-mapping is often associated with increasing the power and torque of a vehicle for want-to-be racing drivers. This isn’t always the case, it can also improve fuel consumption, create smoother power delivery and even help in eradicating certain engine faults. We had an example of this recently when a customer came to us with an engine warning light displayed on the dashboard of their 2008 Volkswagen Touran. Using ODIS the fault was identified as an EGR  (exhaust gas recirculation) valve problem and it would have to be replaced. On this model, the  EGR valve includes a cooler which makes it a fairly large and costly component that bolts to the rear of the engine so replacing it would be time-consuming too. The alternative and vastly cheaper option would be to block the pipes to the EGR valve to prevent it from causing running issues,  essentially eliminating it from the vehicle. This process is legal and doesn’t impact the emissions when checked for the annual MOT test. The only issue is the engine light would remain on the dash and would be an MOT failure, that’s where the re-map comes in. Firstly we plug in a  computer to read the original file from the ECU of the vehicle, this is then transferred to our dealer portal with instructions on our requirements. In our case delete any error codes associated with the EGR valve thereby preventing the engine light from illuminating when the vehicle detects that it is faulty. Once the new file is sent through it is then loaded onto the computer and transferred back to the vehicle ECU. This process eliminated the problem quickly and easily and also saved the customer several hundred pounds in repair costs. 

Vehicle Engine Tuning Services Sussex
Silica Bag Engine Problems

Silica Bag Engine Problems

A few months ago a customer bought their Skoda Octavia to our workshop with a heater problem, it wasn’t getting as hot as it once did. We ran a diagnosis of the heater system, starting with a check of the electrical components using our V.A.G ODIS computer. This didn’t show up any faults with the sensors or actuators associated with the heater. Next, we checked the cooling system of the vehicle to ensure it was providing enough heat to warm the inside of the vehicle. As soon is we removed the cap from the coolant bottle we could see a problem, something had contaminated the coolant. There were dark-coloured deposits stuck to the sides bottle and it was suspected that this substance had spread further into the pipes and throughout the cooling system. Researching this issue further our fears were confirmed in the way of a TPI. It would seem that to aid the longevity of the aluminum components within the cooling system a silica bag was added to the expansion bottle, the problem is this bag would split, causing the silica inside to stick to the inside of the hoses and block the heater matrix.

In this case, we removed the blocked matrix, flushed the system thoroughly before fitting a new matrix and new expansion bottle (new bottles come without a silica bag fitted). The problem was fixed and the vehicle was now getting nice and hot inside once again. It would seem the silica bag
is fitted to many models of Audi, Volkswagen, Skoda & Seat from around 2014-2018 and the fact replacement bottles are supplied without the silica bag fitted it appears it was an unnecessary addition, to begin with. Since discovering this problem we check for the presence of silica bags when carrying out routine servicing and if necessary we replace the bottle before the bag splits leading to a costly repair. We would advise anyone who owns a V.A.G vehicle made around 2014-2018 to check theirs!