Last Saturday I replaced the timing belt and the coolant pump on my 2.0 AEG. As I was tearing things down, I took some pictures as I knew this will be helpful here. I used the Mark-And-Match technique for the timing belt. I did not even attempt to find the timing mark on the flywheel.
The author of this document shall not be held responsible for any damages to you or your vehicle resulting from following any step discussed in the document. This manual is created only for a pictorial guide and should be used as such!
This manual covers the replacement of the timing belt and coolant pump on a 1999.5 Volkswagen Jetta with a 2.0 AEG engine. This manual also applies for all 2.0 engines found in Golf. GTI and Jetta vehicles manufactured from 1999.5 to 2004. This covers all 2.0 engines in the A4 platform with engine codes AEG and later. ABA engines found in the A3 platform have a different organization and the parts are not interchangeable. The general Mark-And-Match principle could be used for any other engine with a timing belt.
1.Timing Belt. The part number is: 06A 109 119 C
2.Timing Belt Tensioner. The part number is: 06A 109 479 C
3.Coolant Pump. The part number is: 06A 121 011 T
4.Four stretch bolts. The part numbers are: N90596902 and N10209606. You need two of each or total of 4.
5.G12 coolant. The part number is: G 012 A8FA4
Volkswagen has revised the coolant pump for the A4 4 cylinder vehicles. The impeller on the older part number is made out of plastic. This often caused it to break and the coolant pump to malfunction. This resulted on overheating of the engine as the pump could no longer circulate the coolant. Sometimes, pieces of the plastic impeller will wedge in and block the movements of the coolant pump. This may cause a timing belt failure. The new design of the coolant pump has a metal impeller which is much more reliable. It is highly recommended that you replace the coolant pump if such maintenance has not been performed yet. All coolant pumps come with sealing O-rings. ECSTuning.com sells excellent 2.0 timing belt kits. They also have the new design of coolant pumps with metal impellers.
With the AEG engines and later, in order to remove the timing belt, you must remove the passenger side engine mount assembly. There are four self-locking stretch bolts which MUST be replaced each time they are removed. It is discussed later in the document.
1.Two jack stands.
2.Three empty one gallon plastic containers. Used jugs from windshield wiper fluid will do great.
3.Long neck funnel
4.Long nose pliers (shown below).
6.Torque Wrench (recommended, but not necessary)
8.Wrenches and various bits
9.Various hex bits for your wrench (metric only. Make sure you have them)
10. Nail Polish (preferably bright color)
Step 1 (Preparation):
1.Jack the front of the car as high as possible and support with the jack stands.
2.Remove the passenger side wheel
3.Remove the wheel well plastic liner
4.Remove the plastic shield under the engine
5.Allow the engine to cool down
6.Remove the engine cover
Step 2 (Draining the coolant):
* Note: Skip to Step 3 if you are not replacing the coolant pump
1. Turn the dial of your heater to hot and remove the coolant expansion tank cap
2. Under the driver side of the radiator you will see a drain plug. It has a valve on it:
Turn the valve counter clockwise for 45 degrees. You will hear/feel click. Slightly pull on the valve. At this moment, coolant should be flowing. Capture it with the long neck funnel and direct it to the empty plastic jug.
Depending on how high you have raised the front of the car, expect to fill 1 plastic jug.
Step 3 (Timing The engine):
Note: This is not necessary at all if you are following the Mark-And-Match method for replacing the timing belt.
1. Using a 19mm socket and a breaker bar, slowly turn the crank bolt counter clockwise.
2. Try to align the timing mark of the cam sprocket with the timing mark on the valve cover:
Step 4 (Removing Various Parts):
1. Remove the coolant expansion tank
2. Unbolt the power steering reservoir, but do not remove it
3. Tuck away all electrical connectors and coolant lines. The more space you free the better for you.
4. Support the engine from below with a jack, preferably a hydrolic one. You can place a rubber piece between the jack and the oil pan if you are afraid that you will crack something. Later you will need to be able to jack the engine up and down in order to manuever the passenger side engine mount.
5. Unbolt the 4 stretch bolts of the passenger side engine mount. The actual mount is comprised of two pieces: One that mounts to the frame and one that mounts to the engine block. You need to remove both.
Here the frame piece of the engine mount is removed:
6. Unbolt the other piece of the engine mount, the one that bolts to the engine block. It holds on 3 bolts. One you can see from the top, one from underneath the engine and one cannot be seen but can be felt by hand.
7. Now try to manuever that second piece of the engine mount away. It is somewhat triangular in shape and it is very hard to deal with in the tight space that you have to work with! It took me 20 minutes to realise that I must jack the engine up and down.
8. Now the passenger side of the engine should be free and supported only by the jack from underneath.
9. Remove the accessory belt and the accessory belt tensioner my removing bolts 1, 2 and 3:
Note: if you are not replacing the accessory belt, make sure you mark the direction of rotation. This is essential when reinstalling it for later use.
10. Using the 6mm alen bit and a wrench, remove the 4 bolts that hold the vibration dampener to the crankshaft sprocket. You must block the cranckshaft from rotating! Here is how I did it:
11. After you remove the 4 alen bolts, it will appear that the vibration dampener sits behind the 19mm crank bolt. This is not the case. Simply twist and pull on the vibration dampener and you will get it out:
12. Finally, remove the lower and middle timing belt covers. There are total of five 10mm bolts. One of the bolts holds both the middle and the lower timing belt covers. Keep this in mind when reassembling.
Step 5 (Marking The Timing Belt):
1. With nail polish, mark 1 tooth on the camshaft sprocket and the corresponding tooth on the timing belt.
2. Select another tooth about 2-3 teeth down the line and mark again.
3. Now you should have 2 marks on the cam sprocket and 2 corresponding marks on the timing belt:
4. Mark 3 consecutive teeth on the cranksaft and the timing belt:
5. Wait at least 10 minutes for the nail polish to dry up.
Step 6 (Removing The Timing Belt):
1. Using a 13 mm wrench carefully loosen the nut on the timing belt tensioner. You should see the tension slip and the belt looosen.
2. Remove the 13mm nut and the washer behind it. Make sure you keep them on a safe spot.
3. Slip the old timing belt off starting from the cam sprocket.
4. Take the old belt out and away
5. Remove the old timing belt tensioner
Step 7 (Removing The Coolant Pump):
1. The collant pump is held by 3 bolts. However, in order to remove the coolant pump, you need to remove that "useless" metal piece above it:
2. Here is a close-up of the coolant pump area:
3. Put a thick rag on top of the crank sprocket. Coolant will spill and you want to minimize the spilage.
4. Remove the old coolant pump and install the new one
5. Bolt the new collant pump and make sure it sits flush with the engine block. Turn the coolant pump by hand several times to make sure it is not grinding or catching anywhere.
6. Wipe out all the spilled coolant. This is VERY important. You must make sure that the timing belt area is clean from coolant as it can compromise your new timing belt!
Step 8 (Marking The New Timing Belt):
This is the single most important step. Either you nail it, or you mess things up!
1. Now, on the new timing belt, mark 3 consecutive teetch, just like you did on the old one.
2. Next, on the old timing belt, count the distance between the crank marks and the first mark that you did on the cam sprocket.
3. Double count the distance.
4. Next, on the new timing belt, count the same number of teeth (same distance) and mark again.
5. Finally, on the old belt, count the distnce between the first and second cam mark and transfer.
6. Check all marks for acuracy. This is the crucial part!
Step 9 (Installing The New Timing Belt):
1. Slide the new timing belt down:
2. Match the marks on the belt with the marks on the cranshaft sprocket:
3. Slide the new timing belt tensioner on. Do not install the washer and the 13mm nut yet.
4. Next, guide the timing belt around the coolant pump sprocket and the timing belt. The camshaft sprocket comes last.
5. Slide the timing belt on the camshaft sprocket about 1/3 the way in, while observing the marks you created. Check to see if you have it correctly on. Note that the new timing belt will appear shorter as it is not as stretched as your old one. It WILL be harder to slip on.
6. Finally, slide the belt completely on and center it on the cam sprocket:
7. Verify that all timing marks are matched and everything corresponds. If your are off by a tooth somewhere, then you must remove the belt and try again!
Step 10 (Tensioning The New Timing Belt):
1. Slip the washer on the timing belt tensioner stud and install the 13mm nut.
2. Hand tighten the nut
3. Using the long nose pliers, turn the U-shaped part of the tensioner clockwise till the little finger at the back of the tensioner is lined with the tensioning mark:
4. Now, the tricky part: while maintaining the tension with the pliers, use the 13mm wrench and tighten the 13mm nut on the tensioner. Remove the pliers and verify for proper tension.
EDIT: I've been receiving a lot of emails and IMs from people who are not very clear on how much to tension the timing belt tensioner. So here are some more pictures that will hopefully clarify things for you:
Here is the timing belt tensioner without any tension. Notice the position of the "fingers":
...and here is how the timing belt tensioner should look like when it is properly tensioned:
Step 11 (Verifying Things):
1. Make sure that the 13mm nut on the tensioner is tight
2. Check the timing belt tension by observing the little finger on the tensioner. It must align with the tension mark (a Y shaped lever)
3. Verify all timing belt marks one more time
4. Now, with 19 mm socket and wrench, turn the crankshaft clockwise slowly. You must make at least 2 complete turns. The last 1/4 of a turn or 90 degrees must be non-interruptible.
Step 12 (Reassembly of misc parts):
1. Install the engine mount. You will have to muve the engine up and down to free up space to manuever the engone mount in place.
2. When installing the frame piece of the mount, make sure that you use the 4 new stretch bolts mentioned in the beginning of the document. These MUST be replaced each time they are removed!
3. Install the timing belt covers and all other parts that were taken off
4. Pour coolant, cross your fingers and start the engine.
Hopefully you nailed it!
It took me 6.5 hours to perform this as I was working alone and progressing slowly. I was making sure that I double and triple check things. I lost a lot of time messing with the engine mount. The verdict: I had fund doing it and I save A LOT of money.
Modified by vasillalov at 2:17 AM 7-3-2007