QuestionMy question today is about shaky condition. The engine is running smoothly. from what I feel, the problem should be from the suspension system. I think it might need alignment but I just want to at least locate the potential problem first. It tends to get very shaky when the car reach certain speed- some were around 50-55 range. Then, it tends to calm down a little, when the speed was highter, but it is still shaky. I just toped off the rear axle fluid. It is not helping much. I also think that the break disc needs to be worn out too because the break paddly was shaky big time when I steped on the break. But I just do not think that It was solely because of that alone that make the car shaky because It is shaky still, even when I did not step on the break.
Secondly, I just changed the whole A/C system- compressor, clutch, evaporator, etc. Firstly, It seemed that the compressor is working all the time without stopping. I changed the ac switch located on the accumulator too. Could that be a problem sir? Secondly, The auxilary fan is not working at all from what I see, but the machanic told me that he did a research on the issue and it showed that for Volvo, the fan will only work when the car is getting overheated. Is that true sir? Also, my A/C control unit has a very weird problem too. It has been this way for long time. It has a mechanical control unit (not the automatic one). when I turn off the fan, the fan is not turned off completely. It is still blowing air and the air speed is probably in level 1 when compaired with the normal usage. I have not checked, if the compressor was still working, when I turned off the fan. What is the potential problem for this one sir? Is the changing of the control unit helps? thank you.
AnswerHello Art, Well it sounds like you have a classic two for one.First the brake rotor warppage will cause a severe shake when initially brakeing.It can lessen the heavier you brake.The tire seem to be' out of round',one or both the front.Note the rim for any damage a tire balancer is best.Also there 4 bushing in the front susp.that wear noticbly Strut rod bushings.You can feel a certin 'dip'when the car stops.There are two per side.As for the a/c yes early years,later the a/c fan on auto issued.To check,with key on engine off,pull the insulation back and bridge the two posts and the fan should come on.If not replace the switch.they,re not expensive and use carb.cleaner for the lubicant,trust me ,it works good.If the a/c is switched on the fan will run at sp.1 with the key 'on'.No danger to the comp. Thank you and good hunting! PKD
