1995 Volvo 960 Current timing belt advanced one tooth!

DracerX · Post by **DracerX** » 22 Aug 2013, 13:11

Changing the timing belt on a 1995 Volvo 960. Car has 82K miles and I'm not sure if this is the original timing belt or not. Recommended change interval is 70K.

When aligning the cam sprocket marks, the crank marks appear one tooth behind lineup.
When aligning the crank sprocket mark, the cam marks appear advanced.

Car still ran fine, no codes, and got 21.5-22 mpg which is correct range.
Installation appears to be one tooth advanced on cams. Could belt stretch put it off this much? I'm used to working on timing chains.
Should I advance so marks line up or leave it as is?
This is an interference engine, and by my calcs, this has the cams advanced my 7.8 degrees.

DracerX · Post by **DracerX** » 22 Aug 2013, 14:16

Reference Step 11 on this website for timing procedure:
http://www.atthetipwebs.com/technologyi ... g_belt.htm

Cam gears lined up on notches:

Crank gear should line up on raised casting line. Crank gear tooth has a small notch cut into the rear face of tooth. Appears retarded when cams aligned:

With Crank gear aligned:

Cam gears appear advanced:

I've already put 15K miles on it in this condition.

DracerX · Post by **DracerX** » 22 Aug 2013, 17:13

Whoever worked on this vehicle last definitely did not have adequate skills. The cams were indeed advanced, as the belt I replaced was not original. It was the same Gates part number as the belt I installed today, and it does not look like the belt had stretched at all. After aligning all the marks, I was able to install the new belt, rotate the engine through numerous times, and the marks all line up properly. In addition, I replaced the spark plugs while having everything apart. The plugs were VERY difficult to remove. They sounded like overly tightened lug nuts coming out. Previous mechanic obviously over tightened them, and did not use any anti-seize. After all this, I hope that the mileage picks up, since the cams were advanced for who knows how long.

lindy8_man · Post by **lindy8_man** » 23 Aug 2013, 22:29

How is your compression? With the cams advanced like that, I would be concerned about excessive cam and valve wear... You know compression and burn when the cams are a little past that point. Did you notice any pinging? smoke?

DracerX · Post by **DracerX** » 26 Aug 2013, 07:28

I wish I had taken compression and vacuum readings for this car before I started the work. Had I known the timing was out of whack, I would have. I have never heard any pinging or seen smoke, and have always filled with 87 octane. With the proper cam timing, seat of the pants meter registers a little less bottom end torque, but the car no longer feels like it's tongue is hanging out at highway speeds. Definitely better power on the highway. I hope this improves the mileage as it spends the majority of time on the highway.