Hi,

I want to say thank you in advance. Can someone help me please. I have a 2000 c70 convertible high turbo with 68k, Automatic. While driving on the freeway with a my foot on the gas to maintain speed at around 60-70 MPH, the car would pause for half a second and would jerk/accelerate slightly. It would happen every time the speed is constant.

I have a feeling that the engine is misfiring somewhere. The car accelerate fine if i press on the gas pedal. I wonder if I need to do a tune up since I did not have one yet and plus I have not change oil for the last 6k.

Please advice

Thank you

 

Usually if it is misfiring the check engine light flashes when it is misfiring.

The turbo control valve might be bad as well.

 

Tech,

Thank you for your advice. I want to know what do you think i should do next. So i took my car to a local mechanic shop. After scanning the car, the mechanic said there are a few error codes, transmission, etc, but it all aims to the speed sensor. He thinks I need to replace it but there is no guaranteed because his scanner is limited.

He suggests that if i want to narrow down the problem, I will need to take it to Volvo. Only Volvo scanner can detect it. It will cost me $130 to just have volvo run diagnositc. However, he said the speed sensor is only $100 and he can replace it for me to see if that will fix the problem.

Please advice. I will be waiting.

Thank you

 

Is there any way you can get us the codes?
This way I can look into them more.

 

Tech,

The code are 722 1633 and 1618. Please advice.

Thank you

 

Is the ABS light on?

 

Tech,

The ABS light is not on right now. However it was on 2 weeks ago, but I sent it into Victor, from a link in another thread. Other lights were on but went off after Victor rebuilt the ABS module for me, except the engine light.

The the car has been pausing and jerking/accelerating since there was a problem with the ABS module.

Please Advice.

Thanks

 

Have the engine codes been cleared after the ABS was fixed?

 

Tech,

No the engine light has never been clear since the ABS module is fixed.

Please advice.

Quan

 

I wonder if the engine module is storing the code and setting it in the other module.
You might want to try to get them cleared.

 

Tech.

I have the mechanic clear the engine light but the car still jerk/jolt when i keep steady speed on the freeway at 60-70mph (also at cruise control). From reading other post, do you think i should change spark plugs, etc and do the usual tune up? My car has 69k and I have not done any tune up yet.

Also from other post, some one had similar problem and they changed the crankshaft sensor and it fixed the problem.

Please advice

Thanks

 

If you have never had a tune up I would start there.
Also another possibility is a bad turbo control valve.