Troublesome Volvo (98 AWD V70 station wagon) - knocking on turns

My girlfriend and I are having much trouble with our new-to-us '98 Volvo station wagon (V70, AWD). It’s got about 110k on it, and I should hope, last many more. It’s been in the shop 3 times so far, and all that’s been fixed is the master control switch for the power windows on the driver’s side door (which finally works well).

Since we’ve owned the car (3 months, now), we’ve had a knocking sound that can also be felt in the steering wheel on turns (particularly sharp ones) and it happens turning right or left. The previous owner had brought this to his Volvo dealership and they thought the wheel was touching a loose fender, which they found under the car by one of the front two wheels (I believe it was the right one, but can’t remember), but commented that it hadn’t fixed the problem.

My mechanic of 5 years, claimed it was related to a failing power steering pump and a damaged rack. The replacement of which would be over $1,000. Since he’s a good guy, he charged me $1,024 (got a free alignment), and it’s finally back in our hands. However, the problem has NOT GONE AWAY AT ALL! The stiffness of the steering still changes on turns or curves (it’s like rolling a dice as to whether it’ll behave like it should on each turn), and it still makes the bumping noise and vibration on (some) turns. Plus the service light and the check engine lights still come on – however, they do not remain on or consistently come on when the car is started.

When the check engine light is on, the AC seems to not work (the air coming out is a bit cool but not “cold” like it should be). Perhaps that’s related to a malfunctioning temperature gage, since this AC you set by setting the temperature you want (separate for driver/passenger side). My mechanic “found no problem with it”.

Between the last time we dropped off the car and the time before that, the AC was making high pitched wheezing noises when it was turned off and strange knocking noises that sounded like an animal was kicking the fans within the dashboard or something, it’s tough to describe. Since we got the car back last, that hasn’t happened (maybe it was the power steering pump?). However, it still gives out a high pitched noise a few minutes after the AC (or the car) is turned off. Again, my mechanic apparently couldn’t hear any of this.

We were told to bring the car back and have the mechanic drive around with us to point out all the issues. Before we do that, please give us a sense of what could be causing the bumping noise/vibration on every turn (and any info about the service lights/AC issues while you’re at it)!

Check that the tire tread depth and tire make/model/size all match. Otherwise you will stress out the AWD and hear that knocking.

Since its 9 years old, the CV joint boots have probably split by now. usually most people don’t know the boots are split until the front end starts clicking on turns. It doesn’t take long for the CV joints to be ruined when the boots split, a matter of weeks. In a month or two, the clicking can turn to knocking.

Most people opt for reman replacement axles. Filling with a heavier grease and putting on new boots is often all that is done to reman axles, so they are no better, and sometimes even worse than the axles being replaced. I think you have one or more bad CV joints.

There are a variety of brand new axles made in China on the market today. They cost about the same as a reman, but they are new. The quality is pretty good. I have a pair on an old Toyota because after several attempts, I could not get a reman that didn’t knock or click right out of the box. The EMPI’s are smooth and quiet, even makes shifting into third gear with the marginal syncros smooth again.

I just put a pair of genuine brand new Honda axles in our 97 Accord. Very expensive, next time I’ll get the Chinese axles for a fifth of the price. I actually had to assemble the Honda axles where the EMPI’s I bought for the Toyota were complete.

Talk to you mechanic about the possibilities of the Cv joints causing the problem and about getting EMPI or GSP axles as a replacement.

As for the AC, it is probably equalizing pressure between the high and low sides, typical after being shut down. Mice do find a way into the fan assembly from time to time. If they die in there, it can really stick up the car.

Ok… we had a LOT of work done on the car, spending over $2,500. The mechanic replaced the steering rack and pump, as I already mentioned, and now he did all sorts of work. He replaced the control arms, axels, charged the AC and replaced a pump that was part of the AC system. There’s probably more to it than that, but all that seems fixed is the AC & heat now work, but we still have the high-pitched hissing noise when we turn it off.

The CV joints were gone and the axels did need replacing, plus I saw how rusted out that pump on the AC was, but can’t understand why it’s still knocking on turns!

The control arms and axels that were installed were Chinese and new, with lifetime warranties.

What do I do? Could it have been something else?