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This article is divided into two parts: part 1 which deals with removal of the timing belt, and timing belt part 2 which describes installation of the timing belt and final checks. Post comments or ask questions about this article in the mk4 VW Passat TDI forum. Also review 1000q: BHW TDI engine water pump removal. Disclaimer- this article is revised and updated to include the most current information but is not a substitute for the factory service manual! See the TOS Agreement for the full legal disclaimer. Although a timing belt job can successfully be done with basic tools plus the timing belt tools and basic mechanical experience, improper installation of the timing belt can cause severe engine damage so take all precautions listed in the factory service manual.
If you find the tips on this page helpful, please use the donation button at the top so that I can continue to keep publishing great articles for free. The Bentley service manual is about $80 and doesn't even include any TDI engine specifics. This page has color photos, more detail, and videos. I know it will save you some money even if you are just reading this to know what to ask a mechanic. Thanks in advance!
VW shortened the timing belt replacement interval from 100,000 miles to 80,000 miles. If you look at VW's website they say check at 80,000 and replace at 100,000 miles for the 2004 and replace at 100,000 miles for the 2005 even though the engines are the exact same. Some believe that the lower mileage rating isn't because of the timing belt but a way to check for other problems like balance shaft oil pump failure. (see 1000q: BHW oil pump FAQ for more details and 1000q: balance shaft module replacement for the procedure). Some TDI mechanics use the original 100,000 mile timing belt replacement interval but when and what maintenance is done is your responsibility. In the end, delaying this critical service won't save money in the long run but it's unlikely that the timing belt will fail at 80,001 miles.
If you've never done a TDI engine, the main difference is that you must buy/rent/borrow the timing belt tools. You can use a spanner wrench or a large adjustable 2 pin wrench to turn the camshaft sprocket and the camshaft sprocket pin can be substituted with any pin of equivalent diameter and length. However, the crankshaft lock cannot be substituted. I tried both the metalnerd and zdmak crankshaft lock. In my opinion, the metalnerd tool is a slightly better fit than the zdmak crankshaft tool but both have some play. The metalnerd crankshaft lock is a finely machined fit on the BRM engine but it uses an oval sprocket, your BHW sprocket is round and that may be why the fit wasn't as exact.
If you are not familiar with the engine bay, label each plug or wire with a piece of tape and marker, not pencil. It will make reinstallation much easier, especially if you are doing other maintenance items over more than 1 day. See 1000q: tips for the mechanic for more handy tips. Please read all of the instructions in the factory service manual thoroughly and the tips here before attempting the timing belt replacement. If any pictures are not showing up or you have any questions, do not hesitate to ask at the forums here: myturbodiesel.com forums. If you are not comfortable that you can successfully do this job after reading the instructions in your factory service manual and the tips on this page, take it to an experienced VW TDI mechanic!
Timing belts cannot be visually inspected for anything other than obvious major wear. They look fine until a tooth breaks off and the sprockets slip, causing engine damage. TDI belts normally don't fail by suddenly snapping in half. When you change the timing belt, I strongly suggest also changing idler roller pulley, water pump, and tensioner. Even if the new belt can last 100,000 miles, the other components may not so change them all. Since they have to be removed anyways, replacement of the serpentine belt and AC belt are also suggested.
(click links to compare current prices and kit components, shipping, tax, etc. )
timing belt kits from Dieselgeek kit, MetalManparts kit. The different kits contain slightly different parts. Because these are all well known TDI vendors, the linked generic parts are often made by the same supplier as VW and are just as good as genuine VW parts. The kits above may vary in exactly what parts are included. Below are the individual components.
Also get some G12 coolant to replace lost coolant. You only need 3 liters of coolant or 1 gallon and an equal amount of distilled water for the timing belt job and to account for any spilled coolant. (Do not use generic green coolant, see 1000q: coolant flush and bleed for more details) , (1 gallon size , VW #G 012 A8F A4, 1.5 liter size, VW #G 012 A8F M1), from MM, dieselgeek (1.5 liter size, VW #ZVW 237 G12)
CAUTION - generic parts available on ebay or other online sellers may be of questionable origin. The above linked sites are all well known and experienced TDI vendors.
CAUTION - I would not buy the or any other of this seller's copycat sites' timing belt kits or tools. These are almost certainly low quality copycat parts! It's not worth saving $75 when it can result in thousands in engine damage! I also had a bad experience with this seller so never again.
Get a metal impeller water pump. I avoid the plastic impeller water pump since they sometimes fail and spin on the shaft. This will cause the coolant to overheat.
(I recommend a kit - generic
parts linked here are suppliers to VW so the parts are the same, just not in VW
timing belt VW# 038 109 119 p (same as the BRM part)
timing belt tensioner VW# 038 109 243 m (same as the BRM part)
idler roller/pulley VW# 038 109 244 j (same as the BRM part)
water pump VW# 038 121 011 j (I suggest a metal impeller pump, different from BRM part
serpentine alternator PS belt VW# 038 903 137 t
AC belt VW# 06b 260 849 a
harmonic balancer bolts (quantity 4) VW# n 103 036 07
Although the Bentley service manual doesn't list the tensioner nut as always
replace (and completely omits the idler roller nut), many timing belt kits include
them and the torque specs include a final turn which suggests they could be
single use only. I use a light touch of blue
medium strength Permatex locktite on them as insurance. According to the
Permatex blue locktite data sheet, you do not need to adjust torque values.
15mm tensioner nut VW# 038 109 454a (same as the BRM part)
13mm idler roller/pulley nut VW# n 015 083 15 *NOTE- some vendors substitute n 015 083 11 from the BRM engine - it uses the same belt/tensioner/roller so I don't know why the part number is different.
crankshaft lock VW# T10050
timing belt tensioner pin VW# T10115 (pin with the triangle handle, optional and not suggested since most tensioners include one in the box, may not apply to your procedure anyways)
2 pin spanner wrench VW# 3387 (your replacement tensioner may have spots for both the spanner wrench and a 6mm allen wrench)
WARNING: There was a recent batch of VW tools tool 10050 which had the pointer arrow in the wrong spot to the right of the peg. It should be to the left of the peg. See this post in the forum for more details.
These tools are available as a kit from metalnerd and are distributed by dieselgeek for metalnerd. They are also available for rental from MMparts. As noted before, I found the metalnerd crankshaft lock an exact fit so I recommend it.
I also rent the tools as a courtesy service, see this page for details: myturbodiesel tool rental
VW tool# 3411 - needed to move the lock carrier to the service position (The dieselgeek timing belt kit includes a pair of 120mm long bolts that are a substitute), see 1000q: lock carrier service position for more details
10, 13, 16, 17, 18 mm sockets/wrenches.
6mm allen bit
regular pliers and spring hose clamp pliers (pictured below right, these are optional and are the remote operated type)
wheel chocks/blocks of wood, floor car jacks, jack stands
Remove any loose necklaces, hair, sleeves, etc., when working on your car, consult your factory service manual for all cautions and notes, always wear eye protection, see the TOS for the full legal disclaimer.
Put the lock carrier in the service position. See 1000q: lock carrier removal for a detailed procedure. Basically, you slide the front bumper/radiator/fan assembly to the front by 4 inches to get easy access to the front of the engine. The pictures in this procedure were taken with it off for easy illustration.
Raise the car, chock the rear wheels, rest the car securely on jack stands, and make sure the car is safe and secure before doing anything else. Remove the splash shield under the car, see 1000q: splash shield fastener and removal for more details. I use DIY wood blocks to rest the tires on, see 1000q: wood blocks for more details.
Side note: If you find the upstream connection (at the intake manifold) keeps popping off you can buy an aftermarket clamp from kermatdi.
Remove the AC belt by loosening the tensioner (2x 6mm allen bolts). Use a wrench/socket on the tensioner body's knob (17mm) to loosen/tighten it. Remove the serpentine belt by putting a 19mm open wrench on the serpentine belt tensioner knob and rotating to loosen the tensioner. Make sure your fingers don't get pinched by the serpentine belt during removal! See 1000q: serpentine belt AC belt removal for more details, pics, and the tightening procedure for the AC belt.
the plastic coolant fan from the fan clutch (4x 5mm allen bolts, already removed
in the pic below).
Remove the center rubber dust cover. Remove the crankshaft pulley aka. harmonic balancer pulley/serpentine belt pulley (4x 6mm triple square or allen head bolts). Caution: do not remove the 19mm 12 point center crankshaft sprocket bolt since it's a one use only stretch bolt! Counterhold the allen head bolts by having a helper put the car in gear and step on the brakes. This will prevent the pulley from turning and it's easier than using 2 tools in a limited space. You can also use a 19mm 12 point socket on the center crankshaft bolt to assist counterholding. If you don't have a helper the 19mm socket will be fine by itself. As long as you don't apply great force to the center bolt, it will not damage the center bolt or crankshaft.
The allen head bolts tend to be soft, if they get stripped you can use lock
clamp pliers to turn the heads or a bolt out kit/EZ out kit like the one
pictured below. When using EZ outs, make sure the teeth are sharp and
aren't spinning on the bolt heads. Don't hammer them on, just press hard
while you turn the bolt out tool counterclockwise. Similar tools are available
at autozone or napa.
Remove the upper timing
belt cover (2 spring clips). Remove the middle and lower timing belt cover (5x 10mm bolts).
middle piece overlaps the lower piece. You have to move the serpentine
belt tensioner to the side, loosen the 6mm allen bolt on it's pivot underneath
the fan clutch (refer to the above belt picture).
You can now see the timing belt. Using the 19mm crankshaft sprocket bolt, turn the engine clockwise to top dead center (TDC). The engine is at TDC if the crankshaft lock and camshaft sprocket pin fit correctly. This is detailed in the next few steps. While you could also turn the engine over at the camshaft sprocket using a counterhold bar, this is not recommended. Despite having more teeth engaging the timing belt, it pulls on the tensioner side of the belt instead of the water pump side of the belt. This stresses the tensioner so don't turn it over there unless you're discarding the tensioner.At TDC, the toothed window in the camshaft sprocket will be on its upper half and the crankshaft sprocket index mark will match the pointer on crankshaft sprocket lock T10050.
When inserting the crankshaft lock, don't push it down onto the crankshaft sprocket teeth, slide the interlocking teeth of the tool into the teeth of the crankshaft sprocket. In other words, don't push it down towards the ground, slide it in towards the engine. The peg on the lock must fit into the hole on the front flange (the metal part behind the sprocket). Refer to the pictures.
Also note the raised bump for aligning the crankshaft sprocket to the crankshaft pulley. 1 of the bolt holes is offset and the pulley will only bolt on 1 way.
Your crankshaft lock, T10050, has the mark at the 12 o'clock position inline with a bolt hole and is used with a round sprocket, not the oval crank sprocket used on later engines. VW made a few defective tools where the the arrow was to the right of the hole. See this post in the forum for more details.
The reason why you must turn the engine clockwise is because there's a little play in the belt system. I've also found that the crankshaft lock will have a tiny bit of play against the teeth. The service manual says that it's not reliable to set the crankshaft lock against the running direction. If you pass the mark and the sprocket moves too far, turn the engine counterclockwise far enough for any belt slack to be removed (at least 1/8 turn) and try again in the clockwise direction.
Now insert the VW 3359 locking pin into the camshaft sprocket. At TDC, it should go all the way through the sprocket, through the hub that the sprocket mounts onto, and into the hole on the cylinder head. Make sure that the pin is engaged all the way into the hole! Verify it with a mirror!
Here is a closeup of the hole on left, the sprocket removed, and the hub
removed (hub removed for illustration only).
The camshaft toothed window should be on the upper half of the sprocket.
If the pin is only halfway in then it's not in the hole. It should be a
tight fit. Make sure you're not inserting the pin into the empty space way
below the hole. (If you've triple checked the hole position with a mirror
and find that the pin is a hair off and won't go in, that's OK. Once you
remove the timing belt you can use the 18mm center bolt to slightly wiggle the
camshaft hub 1 or 2 degrees to insert the pin. If it's more than a hair
off something is wrong.)
If the toothed window is in the lower half of the sprocket, turn the
crankshaft 1 full revolution to fix it (obviously you must remove any pins or
The timing belt is now ready for removal. Loosen the (3x 13mm) camshaft sprocket bolts (pictured earlier). You may notice that the bolt and pin holes are oval. This lets the sprocket move independently of the camshaft within the range of the oval holes. The best position for the hole that's in the toothed window is in the middle. This also indicates that the bolts are in the middle of their range.
Loosen the (1x 15mm) timing belt tensioner nut. Although the factory service manual says to use the 2 pin spanner wrench VW tool# 3387, I don't see why you can't also use a 6mm allen wrench in the tensioner since they are part of the same piece of metal. Either way, turn the tensioner cam counter-clockwise until you can fit VW tool# T10115, the triangle handle pin, in its hole. Then turn clockwise until it hits the pin. It should look like below. If you are not reusing the tensioner (which you shouldn't during routine timing belt changes), ignore using pin T10015. Pin T10115 may also not apply to your installation procedure.
Now remove the timing belt. The factory service manual suggests removing the belt starting at the water pump. I found it much easier to first remove the 13mm nut holding the idler pulley and remove the pulley. Then remove the 15mm tensioner nut and the 3x 13mm camshaft sprocket bolts. (Removing the pin for a second won't cause the camshaft to move and the camshaft sprocket hub underneath the sprocket won't move.) Now slip off the tensioner and camshaft sprocket at the same time. This will give you plenty of play to get the belt off. After the belt is off, replace the camshaft sprocket and make sure the pin 3359 still locks the camshaft sprocket and the hub underneath. If it moved, use the center 18mm bolt to adjust the camshaft hub's position.
If you want to leave the 3x 13mm camshaft sprocket bolts on and leave the camshaft sprocket on, you can do that too, I've just found it easier to get the belt on with removing the camshaft sprocket and the bolts should be loosened anyways.
Now remove the lower roller/idler pulley (1x 13mm nut) and the water pump, see 1000q: BHW water pump removal. End of part 1- removal. For timing belt installation, see below.
Are there broken pictures or bad links? Have good tips? Please comment in the myturbodiesel.com forums.
If you have not yet replaced the water pump, tensioner, or small idler roller pulley, do so now. These components should be changed every 100,000 miles. To remove the small idler pulley, remove its 1x 13mm nut. To install, put it on and tighten the 1x 13mm nut to 19 ft-lbs. I suggest waiting until the timing belt position is finalized before tightening it since you may have to remove the timing belt during the checks. Just remember to tighten it later.
The service manual suggests installing the tensioner and putting the belt on starting at the water pump. It'll be very tight so this page suggests an alternative method.....
....the rest of the detailed procedure and pictures are in the premium content forum. Join our community and upgrade your account for only $2: http://www.myturbodiesel.com/account/upgrades to view. The exact forum post where this is continued is here , thank you for your support!