2001 s60 check engine light and weird idle noise

lukevolvo · Post by **lukevolvo** » 04 Aug 2007, 01:51

Recently got a check engine light, it has been intermittant past few days. Lean Bank one code. The car is surging at idle between 550 and 1000 RPM. There is also a loud squelling noise, almost a whine. Not a belt and no vacuum leaks. Any ideas on the noise? Going to try an o2 sensor for the check engine light. I 'll post how that goes. Love these cars, wife drove it 75K in under two years no problems with car until now, just a grumpy wife.

CarVolvo · Post by **CarVolvo** » 04 Aug 2007, 04:21

check the wifes check engine light...but cant help you with that..you have to know the model and what keeps her going

why not get a reading of the system before attemting anything?

does your system come with an air pump? Could the steering fluid pump, alternator or a/c compressor or one of the rollers be going?

When was the last time you had your timing belt checked?

Post by **JRL** » 04 Aug 2007, 06:30

Most likely an 02 sensor but since Volvos sensors are expensive why not let a Volvo dealer pinpoint it?
Their computer will tell you exactly which one it is

lukevolvo · Post by **lukevolvo** » 05 Aug 2007, 19:46

The car has 100K miles on it. It is an S60 non-turbo. The check engine light was for lean fule mixture on bank 1 (OBD code po171). I recently had the timing belt and water pump replaced (unrelated preventative maintenance). Checked the oxygen sensor with a multimeter and both are working fine. I was wrong about the vacuum problem, no leaks but there was a clog. Vacuum problem is most likely in PCV system and it is casuing the noise. By loosing oill cap the noise goes away. This car does not have a PCV valve, but I was told it clogs. Took the lines apart found large carbon deposits clogging the bottom line. Cleaned it up and replaced short hoses. Car runs a ton better, idles better, but the noise is still there along with suction on the oil cap.