Vacuum Leak 2000 Volvo S70

Randall0208 · Post by **Randall0208** » 23 Jan 2019, 15:47

Hi there everyone. Been battling with a check engine light for the past few months. They're codes p0135 and p0130. It has to do with the o2 sensors. A few months ago I got the codes and tested my o2 sensors and one of them was shot so I replaced it. The check engine light persisted so I kept testing my two o2 sensors and they were working fine. My gas milage was fine, I got it up to 24 while on the highway for 45 min the other day and my max mpg is 26 according to my manual. I believe I have a vacuum leak because when I first start my car and let it idle the rpms go to around 1100-1200 then drop to around 800 and then fluctuate a little bit and finally stay at 1000. I'm assuming thats the computer kicking in because it needs to compensate for the extra air coming into the engine. If anyone has had a similar problem or has any information please let me know. If anyone knows the diagram and routes of all the vacuum lines please let me know! Thank you.

Post by **abscate** » 23 Jan 2019, 19:50

If it's a non turbo that mileage should be closer to 30 mpg.

I think the 2000 shares the vacuum diagram with the 1999, but there should be a sticker under the hood showing it all

Replace everything

Randall0208 · Post by **Randall0208** » 23 Jan 2019, 19:56

abscate wrote: ↑23 Jan 2019, 19:50 If it's a non turbo that mileage should be closer to 30 mpg.

I think the 2000 shares the vacuum diagram with the 1999, but there should be a sticker under the hood showing it all

Replace everything

It's the non turbo, the owner actually saved the paper that was inside the window of the car when it was brand new basically saying what it featured and it said 26 mpg highway.

Post by **abscate** » 24 Jan 2019, 00:56

That's the EPA highway estimate which is consistently low from actual. My comment was based on actual mileage reported by persons here for naturally aspirated ( NA) cars in the 1999-2000 vintage

There is a nasty bit of vacuum hose under the intake manifold , I think, that is easy to miss

I can't remember if the 2000 kicks up high idle on startup. There are a lot of things going on with startup to keep emissions down, so I'm not sure if fluctuating idle is a good diagnostic for vacuum leaks. The best way to eliminate them is simply going through the system with a marker, Remove each hose, and replace