timing belt

Pcar · Post by **Pcar** » 18 Feb 2011, 09:42

While changing my plugs the other day on my 1999 xc70 (150k) I noticed the timing belt wasn't riding right in the center of the pulleys, it was off to the side about a quarter inch. The belt was replaced by an independent about a year ago. Should this be looked at ?

Thanks for any advice , Mike

Post by **jimmy57** » 18 Feb 2011, 09:53

That usually isn't a problem but if it is due to worn water pump or loose idler or tensioner then IT IS A BIG DEAL!
IS the belt off the front of the pulleys? Any signs of belt fraying on the edge off the pulleys (if it is off the edge)?

Pcar · Post by **Pcar** » 18 Feb 2011, 18:30

The belt is off towards the outside (away from the engine) I didn't notice any fraying but I'll pop the cover off tomorrow and have a closer look. Is there any way for a DIY to tell if the water pump or idler tensioner need attention ?

Thanks for your help
Mike

Post by **jimmy57** » 18 Feb 2011, 20:23

Noise is one way. If you can scoot the belt back on cam gears and on the idlers and then start motor and the belt runs further back and stays then you're probably OK.
If the front edge of belt is just at the edge of gears and hasn't crawled past thatg then it was probably like that when they did the belt and it is really nothing to worry with.

Pcar · Post by **Pcar** » 19 Feb 2011, 19:28

Checked belt position and condition while I cleaned the MAF sensor .The belt has not passed the edge of the pulleys and is not frayed , it is only one eight of an inch off the inside of the pulleys. There is no unusual noise coming from the engine either.
I was cleaning the MAF because I have an idle problem . When the car has running for a few minutes the idle will pulse up and down (200-500rpm) when coasting up to a stop sign or when in park or neutral. It does not do it when stopped in drive or when the engine is cold. After cleaning the MAF I'll have a go at cleaning the throttle body. Any suggestions ?

Thanks, Mike

MikesS70 · Post by **MikesS70** » 20 Feb 2011, 07:48

FYI: I had the timing belt changed on our '99 S70 at the local dealership (about 3 years ago) ..the belt rides about like yours (1/8th inch in from the engine-side edge). Haven't had any problems with it.

BTW: According to the dealer mechanics, the original Volvo water pump is apparently built like a tank; when I had them change out the timing belt I asked about changing out the water pump (as preventive measure). The shop assured me the water pump was one of the least failure prone items on the car ...that it would last at least through the service life of the new timing belt.

I figure anytime a dealership turns away a profit, there must be an inkling of truth behind what they're telling you.