Timing Belt Question

[mpr3209]

This may be a dumb question, but here goes. recently replaced the timing belt on my wife's 2003 S60. I followed the youtube video step by step. When the job was complete, everything seemed fine. The car ran great--no stutters, no missing, no issues. After about a week I got a check engine light. Took it to the shop and they said the timing was off.

Here's the dumb question: how is it that everything seemed fine for the first week? If the timing was off, why didn't the engine run rough or the the check engine light come on when I started the vehicle after the job? More importantly, if/when I do this job again, how do I know I have everything lined up correctly?

I appreciate anyone's input. This has really got me bugged. I thought I had done this job exactly right.

[cn90]

Did you change both pulleys (tensioner pulley and idler pulley)?

[mpr3209]

I changed both pulleys and followed the instructrions in both the video and the sheet that came with the timing belt to the letter. Odd.

[cn90]

Give this a try:
http://www.autocarepronews.com/issue/ar ... ntid=41905

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Volvo Tech Tip: Adjusting Mechanical Camshaft Belt Tensioner

Use the following procedure when adjusting the mechanical camshaft belt tensioner on 1998 Volvo S70/V70/C70 (B52X2/B52X4) vehicles with engine serial number 1266128-on.

Service Procedure:
1. Install the timing belt.

2. Ensure that the belt is tight between the crankshaft and the intake pulley; if not, reinstall it.

3. Tighten the center screw to 5 Nm (4 ft.-lb.).

4. Holding the center screw stationary, turn the eccentric (A) with a 6 mm Allen wrench counter-clockwise until the tension indicator passes the right side of the adjustment window (B). See Fig. 1.

TB1.gif (6.67 KiB) Viewed 1277 times

5. Turn the eccentric (A) back clockwise until the indicator (C) reaches the correct position based on the temperature of the engine (see Fig. 1).

6. Hold the eccentric secure and tighten the center screw to 20 Nm (15 ft.-lb.).
Note: When setting the final adjustment, the needle (C) must enter the adjustment window (B) from the right. If the needle exits the window to the left, it must be readjusted past the window so that it enters from the right. See Fig. 1.

7. Press on the timing belt and verify that the indicator moves in response to the pressure.

8. If the bolts holding either cam wheel had been loosened, tighten them at this time to 20 Nm (15 ft.-lb.).

9. Press the camshaft belt and check that the belt tensioner needle moves freely.

Needle Position at Different Temperatures:
Note: This adjustment is always carried out on a cold engine. A suitable temperature is approximately 20°C/68° F.


At higher temperatures, for example with engine at operating temperature or at higher ambient temperature, the indicator is farther to the right. See Fig. 2 which shows the needle position when adjusting the camshaft belt tensioner at different engine temperatures.

TB2.gif (7.56 KiB) Viewed 1277 times

Courtesy of IDENTIFIX.

For additional information, visit http://www.identifix.com.

[cn90]

I assume that this is the youtube video you are talking about?

[mpr3209]

It is. Thought I followed the instructions on the tensioner. Maybe I messed it up somehow.