09 September 2022
If your TDV6 exhaust blows blue smoke during acceleration, this simple bolt-on fix can cure it
Need to know
Time: 2 hours
Difficulty: 2 out of 5 stars
Models: TDV6 3.0-litre engined Discovery 4 and Range Rover Sport 2010 to 2013, and Range Rover 2013.
Tools needed: General workshop tool including T27 Torx bit, 13mm and 10mm sockets and long extension, ramps or vehicle lift or suitable jack and axle stands.
Parts used: Oil return pipe, secondary turbo,LR087351, £35.62; Blanking plug and gasket kit,
• Wear protective gloves or barrier cream to protect the skin from oils and sharp edges of components.
• When working under a vehicle check the stands or vehicle lift are correctly rated and in serviceable condition.
• Ensure the vehicle is stable before working underneath..
Thanks to: Steve Parker Service & Repairs Ltd, North Street, Whitworth, Rochdale OL12 8RE. Tel: 01706 854223. steveparkers.com
One of the big improvements for Discovery 4 over Discovery 3 was the uprated version of the TDV6 diesel engine. The original engine in the Discovery 3 was a 2.7-litre with a single turbo. For the Discovery 4, this was increased to 3.0-litre with twin turbos in which the first (primary) turbo would work as normal at lower revs and speed, then the secondary turbo would come in, but it would only start to work above 2800rpm. That meant the second turbo wasn’t being used all of the time. This could lead to a build-up of oil in the secondary turbo’s drain pipe due to, as Land Rover describes it, “ineffective oil drainage system”. This produced excessive blue exhaust smoke when the vehicle was next accelerated hard as the secondary turbo came in.
This problem only affected early Discovery 4 TDV6 models from 2010 to 2013 in the VIN range AA510178 to DA676456, along with Range Rover Sport and the 2013 Range Rovers that used the same TDV6 engine. The problem was subject to a Land Rover Technical Bulletin issued in 2013, and then a later bulletin LTB00487v6 issued in 2015. But this was only acted on when a customer raised a concern of excessive blue smoke from their vehicle to the dealer, hence not all 10-13MY Discovery 4s had the modification done free of charge by Land Rover.
Inner workings of the 3.0-litre TDV6
The mod is a simple solution. Working under the right-hand side (from driver’s seat) of the engine, the long drain pipe from the secondary turbo to the lower sump is removed and a blanking plate fitted in place over the entry hole in the lower sump. A new shorter turbo drain pipe is then fitted from the secondary turbo running to a position higher up in the sump through an existing hole which was originally blanked off by a bolted plug on the Land Rover version of the TDV6 engine. On later TDV6 engines outside of the VIN range (post engine number 0753185) this sump hole was cast over, with no blanking plug.
Fitting the modified drain pipe isn’t a difficult job: basically a matter of removing four bolts, then the pipe itself, the blanking plug, and fitting the new shorter pipe. The most difficult part is the need to remove the starter motor to access the drain pipe, by first removing the starter’s snorkel breather pipe and undoing five securing bolts and two electrical connections before pulling the starter out. The modification isn’t overly expensive, and certainly eliminates the embarrassment of leaving a blue smoke screen when accelerating hard.
Note that when working on the engine’s oil system, all component connections should be cleaned before removal, and care taken to ensure dirt cannot enter the engine while the parts are removed, and during refitting.
Difficult to see: The oil drain tube runs down the side of the engine from the secondary turbo into the bottom of the sump and is only accessible from under the vehicle.
Follow instructions: Before removing the starter motor, the battery negative lead was disconnected and the vehicle was then left, as specified, for 120 seconds to fully power down.
Battery disconnection: When disconnecting the battery, always follow the correct procedure given in the owners’ and workshop manuals, and illustrated on this engine bay sticker. Adhere to the waiting time after disconnection before starting any work; this is normally around 2 minutes which allows for the vehicle’s management system to fully power down.
Remove guards: As all the work will need to be carried out from underneath the Discovery, the first job was to remove both the engine and the gearbox undershields.
Locate the tube: With the shields taken away, we can see and access the turbo oil drain tube but, first, the starter motor needs to be moved out of the way.
Removing the starter motor
Disconnecting: The starter motor needs to be removed for access. This has two electrical connections (red arrow) to release, and two snorkel pipes (yellow arrows) to pull off.
Securing bolts: The starter motor is held in position to the flywheel housing by two securing bolts at the front which were now released and removed.
More bolts: Next, the three securing bolts holding the starter into position at the back to a mounting bracket were undone and the bolts were removed.
Remove the starter: The starter motor was then removed by initially pulling it backwards and then down and out – there isn’t a lot of space to work in here.
Removing the old drain tube
Bracket bolt: The existing turbo oil drain tube is secured in the middle to the engine by a bracket and a single Torx bolt, which was removed and discarded.
Remove top bolts: Using a long-reach extension and a T27 Torx bit, the top of the turbo oil drain tube was unbolted and released from the bottom of the turbo.
Remove bottom bolts: The two securing bolts holding the bottom of the turbo oil drain tube to the sump were undone, then the tube could be released from the sump.
Size matters: With a small loss of engine oil, the original long turbo oil drain tube was removed. The new pipe (top) is considerably shorter than the original.
Installing the modification tube
Unbolt the plug: The existing blanking plug, midway down in the side of the sump, was unbolted ready to take the modified tube. (On later engines this hole is not present).
Fit in place: The new tube was fitted into the hole in the side of the sump, correctly locating its O-seal before fitting the securing bolt and tightening to 10Nm.
Fit and bolt up: The top of the drain tube was positioned and the two Torx bolts fitted and tightened to 10Nm, using a long extension to reach up.
Cleaned: Before the new blanking plug was fitted into the original (and now redundant) lower sump drain hole, the mating face was cleaned of any traces of old gasket.
Plug fitted: With the face cleaned, the new blanking plug was fitted into position checking that the gasket is correctly located, then the two Torx bolts tightened to 10Nm.
Refit starter: The starter motor was fed back up between the cross members and chassis onto its fixing bracket, and the five bolts refitted and torqued to 47Nm.
Reconnecting: The two electrical connections were remade to the starter, and the plastic insulation cover pulled over them, then the two snorkel pipes were refitted.
Final checks: After replacing the undershields and reconnecting the battery, the engine oil level was checked and any oil loss was replaced.
Budget Digital Subscription
Get access to over 7 years of Land Rover Monthly – that’s almost 100 issues plus the latest digital issue. The issues are fully searchable so you can easily find what you are looking for and what’s more it’s less than 10p a day to subscribe. Click here and start enjoying all the benefits now.