I am the proud owner of a new(to me) 1999 s70 awd.(176,000 mi.) I have learned a lot reading here, but now I'm scared, LOL! I am pretty good at fixing stuff but some of the stuff that's in these cars...WOW! anyhow, I have a question..my car sputters at between 1500 and 2000 rpm. it pulls hard until then and hard anywhere else after that. runs fine until it gets warm(about 1/4 on guage), then it does this. just got car and have only done rear pads/rotors, battery,2 frt tires so far. also, is there a way to tell if my car uses 2 or 4 bolt frt lwr control arms with out putting car on lift?

 

Just look at the control arm where it attaches to the frame.

As for it running rough, you need to check codes.

 

thanks...threw no codes...it passed NYS inspection running this way...also service light comes on for about 1 min after starting , then goes out, abs light on but sys works, yellow car in triangle w/curvy lines comes on after about 3 mins of driving, but i haven't noticed anything odd...it doesn't idle or run rough..only loses pwr in this rpm range until i floor it and go above that, or let/keep rpms below that, then runs smooth as a kitten...

thanks rspi

 

went to autozone this morning before work...no codes on car yet...

 

I think you will find your ABS is NOT working if the ABS light is on. The brakes work, but not the ABS. I'd fix that. I think there are some threads about the control module or something along those lines.

Regarding the codes. Unless you are sustaining an issue for a specific amount of time, the codes don't latch in the computer. Sometimes when a code latches it will clear when the problem goes away after some predescribed amount of milage.

If you can borrow the decent code reader or buy on, you can plug it into the car and drive the car. Some will record the codes that are thrown even if they do not latch. You may need a passenger to watch the scan tool to see the codes.

If I was a betting man i would be looking at a vacuum leak. At 175K miles stuff starts to break down. Check the "J" hose - in front of and above the passenger rear wheel. Common problem but usually throws a code, but not always. Check all the vacuum hoses you can see on top of the engine. They are probably heat/dry rotted. Check hoses for the PCV system - lots of folks talk ab out the ones under the intake manifold wearing away where they contact the engine.

Your RPM range is the range the computer moves from the idle curcuit to the normal running circuit. Fuel is controlled by MAF and O2 and a host of other stuff.

 

Thanks Kwatt, I'll check out those things and get back to you...