Turbo trouble
I have a 2004 Jaguar S-TYPE 2.7 diesel and when you put your foot on the throttle after moving slowly you sometimes get very little response for a few seconds, then it takes off like a rocket. This can be a real problem if it happens on a roundabout.
The EML is not illuminated, but there are three stored codes: ‘P0046 turbo boost control’, ‘P010F mass airflow a/b’ and ‘P140A EGR sensor low’. My interpretation of this is that the variable vane pitch turbocharger on bank 1 is sticking. When this starts to happen, I squirt a can of Wynn’s turbo cleaner down the turbo intake tubes for each bank of cylinders and it cures the problem for a few months.
Would it be worthwhile removing the turbos and cleaning them manually or sending them to be refurbished? I ask you this because I am retired and the car only does 20-mile round trips to the nearest town, so maybe it would be better to continue using turbo cleaner every three months. Stephen Forsyth
The full code is ‘P0046 Turbocharger (TC) boost control solenoid/ supercharger (SC) boost control solenoid - circuit range/performance’. ‘P010F’ refers to ‘MAF sensor or VAF sensor A/B – correlation’ and ‘P140A’ is not recognised, but ‘P1401’ refers to the ‘Exhaust Gas Recirculation Valve Position Circuit’ and ‘P140X’ is Egr-related. The codes are all suggesting air pressure within the induction system of the vehicle, so before taking on the job of removing the turbochargers to overhaul them, I would consider cleaning out the EGR valves. It could be that the Wynn’s turbo cleaner is actually having an effect on the EGR valves causing the temporary relief. You have not said what mileage your Jaguar has covered – this will have a bearing on whether or not the cost of having the turbochargers overhauled would be beneficial.
I would also try cleaning the MAF sensors, which can be accessed easily. These sensors can often cause problems, normally without leaving a code. Clean the sensors using a product such as Wynn’s Diesel EGR Extreme cleaner (https://
bit.ly/2l0hrnb), which is designed to be used in the air intake system, inlet valves and airflow sensor, as well as the EGR valve and turbo. This may alleviate the problem if directed in the right area, but it is important that the MAF sensors are allowed to dry fully before restarting the engine as the hot wire element of the MAF sensor could otherwise be damaged.
With your longest journey being a 20-mile round trip, it is possible that the system is getting clogged. I would also consider giving the vehicle a longer trip occasionally, to help burn off the carbon deposits which are likely to be the root cause of your problems.