I have a 1998 s70 GLT. And I found that it consume a lot of gas 12-13 mile per gallon in local. I do not know what' s wrong with my car. which part should be inspected or changed? Whether changing timing belt can help the car? Thanks.

 

also my car has a high mileage about 140k mile

 

Last tune up?
Check engine light on?
Does it run ok?

 

Check to see if you have a vacuum leak at the elbow near the power steering pump. The gas mileage on my 98 S70 w/90k miles was in that range until I had that fixed. Search a bit here and on the web and you will find some additional info. Cheap and simple to fix, cost me about $50 at a nearby garage. Mine did throw a code (p0172) and the Check Engine light was on. Cleared the problem and mileage was back up to normal.

Good luck.

 

Thanks. The chech engine light is not on. All the light is off. And the car runs well.
How to check the vacuum leak? I am living in Chicago. Could you give me some suggestion on where to fix this problem without costing a lot of money? Thanks

 

Read the information here: http://volvospeed.com/Repair/vacuum_lines.php

The first picture on that site has the rubber elbow that caused me the problem. Basically, the computer starts sending too much fuel to the engine thinking it is lean- that is one reason your mileage may be low. It is a little difficult to find, its near the power steering pump on the passenger side. When I finally looked at mine, there was a hole right through it. Had it replaced and been ok since.

 

Thanks. I will try this weekend.
Whether the engine light should be on when there is the vacuum leak problem? Thanks.