My 98 s70 has really rough idling. It rumbles so much at a stop light that when the tach needle falls below 1000 RPM it feels like its going to cut off and the brake pedal hardens and does not grip. Oterwise it runs quite smoothly. Would changing the plugs & wires solve this? or do I need some major work done? any suggestions?

 

Is the Check engine light on?

When was the last tune up done?

How many miles on the car?

Has the throttle body ever been cleaned?

 

i have that same problem minus the brakes and the almost feels like its going to cut off problem. my 99 has 111k miles on it and has been to the shop twice in the last year and they really havent done anything about it. might have something to do with coils or sumthing im not sure thats what the last mechanic said. but it runs fine in everything else so im not too worried

 

Yours could very well be the coils. Has the Check engine light ever flashed under hard acceleration?

 

136,000 miles. and yes, the check engine light has come on, although it was not on when this problem first started. I believe it is due for a tune up, I really hope that takes care of it. I have had it for a little over one trouble free year, I haven't cleaned the throttle body and don't know if the previous owner did. All I did was to have the timing belt & water pump changed when I first bought it because I've heared the horror stories about volvo timing belts after 80,000

 

You need to have the codes pulled. Just because the light isn't on now doesn't mean the codes aren't still there.
It might be a vaccum leak or a bad Mass flow sensor.

 

no check engine light flashes when i accelerate hard, only the traction control when im coming out of a turn, but thats expected...

 

It is still possible for the coils.

 

Tech...you're the man! It was a vaccum leak, also when I pulled the codes, 4 out of the 5 cylinders were misfiring. I had the vaccum hose changed and did an overdue full tune-up(all work done at an independent) and once again my baby's purrin' like a kitten. Thanks again.......I love this car

 

Glad to help. Now you are back to running good!![sm=gears.gif][sm=burnout.gif]

 

I have the identical problem to the OP. Silly question I think, but who can pull the codes and how much does it cost?

thanks!

 

If you are in the U.S. and live near an Auto Zone they usually pull codes for FREE.

 

Tech can you provide an illustration of the vacum hoses to check, for leaks or cracks, in regards to the acceleration sputtering and subsequent cylinder code misfires, please.

 

I don't have any pics but check any line that go from the intake manifold out.
Also could be ignition parts if you are having a missfire issue.

 

Hi, Here's trouble with my s70 1999 non turbo. The motor run on 4 to his 5 cylinders (rough idling and rough acceleration whatever the speed). Find out that the trouble is cylinder 2. The coil make fire when I pull it out of the spark plug, but if I remove the terminal connector from the coil on cylinder 2, nothing happend (same rough idling without change of the idling). If I remove all others connectors of each coil one at the time (cyl.1-3-4-5) you notice that the cylinder is missing the fire and motor had a worst rough idling when I unplug each terminal connector for each coil. As I said this is not happend with coil of cyl. 2. Then I've invert the Coil 2 with a other to be sure the coil is not in fault. Same trouble on cyl 2. So I check the injectors and invert injector of cylinder 2 with a other. Same problem. Want to specify that I've change all 5 spark plugs before my testing. Finally I suspect the ECM module but the coil seem to make a good fire. Maybe it could be a valve trouble.Does it make sense? Any help will appreciate. Here's my code p1040, p1081, p-1300b.