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Turbo removal turbo replacement on ALH engine, BEW engine similar

Apr 15, 2014
Turbo removal turbo replacement on ALH engine, BEW engine similar
  • DIY Turbo removal and replacement on ALH engine Jetta, Golf, and New Beetle, BEW engine similar

    difficulty: 2/5

    Introduction

    Although the BEW is slightly different, the procedure is similar, see your factory service manual for the differences. Many times low power or the turbo cutting out is misdiagnosed as a bad turbo. If you have these symptoms, see 1000q: limp mode diagnosis and 1000q: constant low power or can't rev. Difficulty is only rated 2/5 because it's not technically difficult and doesn't require any special tools other than the normal shop tools. However, it's time consuming and you might run into complications so be prepared.

    The easiest way to remove the turbo is from above because of clearance. The turbo and exhaust manifold are 1 piece. This also gives you the chance to clean the intake manifold of carbon. It might be faster to remove the turbo from below but you would have to remove the passenger side driveshaft. There's also less clearance and there'll be lots of rusty chips falling onto you so I suggest removal from above, as described in this article. Always wear eye protection, note all cautions in your factory service manual, and see the TOS Agreement for the legal disclaimer.

    ALH engine is 1998-2003, BEW engine is 2004-2006 TDI

    Parts/Tools
    Note: service manual says in one place to always replace BEW engine's downpipe nuts, in another place it has no such note, ALH also has no such note. While you can reuse the nuts if they are in good condition, good practice is to buy new self locking nuts. You're also supposed to use new exhaust gaskets but if you're missing one they can be reused. I wouldn't since they're cheap and replacement would require you to remove the turbo again.

    ALH engine (1998-2003 ) parts
    1 turbo oil line VW# 038 145 771 d
    downpipe gasket (always replace) VW# 3a0 253 115
    exhaust manifold gaskets (always replace) VW# 028 129 589 b
    3x downpipe nuts VW# n 908 946 01
    oil union crush washer (always replace)

    BEW engine (2004-2006 mk4) parts
    1 turbo oil line VW# 038 145 771 aa or VW# 038 145 771 n
    turbo oil line union and crush washer (optional) VW# 045 115 677 a and n 013 812 3
    downpipe gasket (always replace) VW# 3a0 253 115
    exhaust manifold gaskets (always replace) VW# 028 129 589 b
    3x downpipe nuts VW# n 908 946 01
    oil union crush washer (always replace)

    5, 6mm allen sockets
    10, 12, 13mm sockets + wrench
    PB Blaster or Liquid wrench
    remote cable operated spring clamp pliers
    [​IMG]

    Procedure
    Raise the front of the car, chock the rear wheels, rest the car on jack stands, make sure the car is safe and secure before getting under it at all!

    Remove the intake manifold. If you have a BEW pumpe duse engine, also see 1000q: BEW intake manifold removal. The BEW engine intake manifold is different but the exhaust manifold and turbo is similar to ALH engine and it will give you a rough idea of what to do. It's not required to remove the EGR cooler - just remove its 3x bolts and tie the cooler out of the way. Also disconnect the VNT actuator's vacuum line from the N75 solenoid. I suggest removing it at the solenoid to avoid disturbing the bottom end.

    Spray all the exhaust manifold nuts with PB Blaster or liquid wrench penetrating lubricant. Pictured below is the exhaust manifold removed so you can picture where the exhaust manifold nuts are. Spray some on the 2x heat shield nuts. Penetrating lubricant will help eat rust, loosen them, and really help prevent stripping. Also put a few drops on top of the oil line union. This will help prevent twisting of the oil feed line when you remove it later.

    The black ball stud on the intake manifold is the "easy pop off" engine cover mod. It replaces the studs/nuts with a pop off connector. See 1000q: pop off engine cover to see more info.
    [​IMG]

    Remove the turbo intake hardpipe (1x 10mm bolt on the intake manifold and 1x allen head bolt holding the other bracket as detailed in the intake manifold removal article). Remove the turbo outlet-intercooler piping. Use the remote operated spring clamp pliers to release the spring clamps at the turbo and intercooler. 1x 10mm nut holds the intercooler piping to the body.

    An ALH turbo is shown - to release the BEW engine hoses, pull the quick connect clip out and the tabs that hold the hose will be released.
    [​IMG] [​IMG]

    Remove the 3x 13mm downpipe nuts (yellow arrows). One may be hidden from below but you should be able to see it from above. The red arrow indicates the location of the oil union when viewed from below.
    [​IMG]

    Here is another view of the downpipe after turbo removal.
    [​IMG]

    Remove the turbo bracket line (1x 16mm bolt) and oil line. If you have a BEW engine the bracket is in a slightly different place.
    [​IMG]

    Here is another view - this oil return line is different because it sits under the turbo bracket. If you have this style of oil return line, loosen it as much as possible. After you start to pull off the exhaust manifold, you'll have enough clearance to loosen the return line all the way to remove it.
    [​IMG]

    Loosen but do not remove the oil feed line at the turbo by counterholding the union while loosening its 17mm nut. Leaving it attached after loosening it will help keep the turbo oil union clean while you remove the other exhaust manifold nuts. Although the service manual says to replace the oil feed line each time, it's possible to reuse it if it's clean and clear. If the insides have buildup or if it gets twisted at all during removal, do not reuse the oil feed line. Do not try to untwist it because once it's twisted at all, it's no longer usable. The journal bearings in the turbo float on a layer of oil and you don't want to restrict any oil pressure.
    [​IMG]

    There isn't enough clearance for a normal wrench so Herm TDI found you can cut a notch in a 12 point head wrench (so it can go around the oil line, like a flare wrench, pics mirrored with permission). This method is the least likely to twist the oil line. eddie1 found that if your wrench is short enough it may fit. While you could use a 7mm allen wrench or square punch wedged between the oil union and turbo exhaust housing side to jam the oil union, it only holds 1 side and could strip the union. I suggest placing it on the cast iron exhaust side and not the aluminum side. A stubby wrench or a crow's foot wrench on an extension (shown right) can reach the upper 17mm oil line "nut".
    Again, if the oil line gets twisted it's no longer usable. Just cut it off for easy removal and cap the end so dirt doesn't fall into the turbo oil line.

    After the oil line is removed wad some plastic or a paper towel into the oil union to keep the insides clean.
    [​IMG]
    [​IMG]

    Also remove the oil line banjo bolt at the oil filter (1x 17mm) and the 2 brackets holding the oil line (1x 10mm bolt on each bracket). If the oil line is still good, just loosen the bolt, pivot the oil line out of the way, and hand tighten it to hold the line.
    [​IMG]

    Above the exhaust manifold:
    [​IMG]

    Under the coolant flange coming off the cylinder head on the driver's side:
    [​IMG]

    Remove the nut/stud holding the heat shield onto the exhaust manifold and then remove the 8x 12mm exhaust manifold nuts. Note the spacer under each nut. Once you are ready to remove the last manifold nut, remove/pivot the oil feed line out of the way. The turbo should now come off.
    [​IMG]

    Installation is the reverse of removal. Use some high temp antiseize on the exhaust nuts.

    When installing the oil line, snug up the union first but don't counterhold it when tightening the oil line nut. Just tighten the nut and it will tighten the union. You only have to counterhold the union when loosening the oil line. This assumes that the union can move freely and isn't rusted. Do not use any gasket maker on the unions. Gasket maker will squeeze into the oil line and could block it. If you are reusing a good oil line, you could put a dab of gasket maker on the outside only after final assembly - never apply gasket maker to the inside.

    Make sure to put some oil in the union and let it run through to help lubricate the turbo. Crank the engine with no fuel to prime the turbo with oil. You can do this by disconnecting the injection pump shut off solenoid wire (single wire with nut on top of the injection pump). After engine start, let the engine idle for a minute to ensure lubrication to the turbo.

    Torque specs
    ALH engine is 1998-2003, BEW is 2004-2006. Also remember that these torque specs assume clean, rust free, dry threads.
    3x 13mm downpipe nuts: 18 ft-lbs
    8x exhaust manifold nuts: 18 ft-lbs
    heatshield nuts ALH engine 18 ft-lbs
    heatshield nuts BEW engine: 15 ft-lbs
    turbo oil feed line union: 30 ft-lbs
    turbo oil return line (on block): 30 ft-lbs
    ALH turbo oil return line (on turbo): 11 ft-lbs
    BEW turbo oil return line (on turbo): 13 ft-lbs
    turbo support bracket bolt: 30 ft-lbs

    ALH intake manifold 6mm allen bolts:18 ft-lbs
    BEW intake manifold bolts: 16 ft-lbs
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