I test drove a '99 C70 HT Coupe and noticed a few obvious problems and wondered if these are common and curable:

1) The worst problem is that it has a bad vibration that seemed to be most noticeable in the frame or seat as opposed to the steering. At 60 -75mph it felt like the wheels would come off. I took it back to the dealer who then drove it and agreed to have the tires rebalanced. Went back one week later and it drives the same. The tires are new.

Is this a common problem? Could it be the brake rotors?

2) Also noticed a shake when the car is first started and the same shake when it is turned off. Is this due to the upper motor mount being bad?

3) During the first test drive I noticed some noise when turning left that seemed to come from the front. Did not notice it during the second test drive. Any ideas?

Is there anything else major I should be aware of in looking for a used C70 coupe?

Thanks…Jack

I have the same vibration problem on my wagon, and the tires are new. I have not yet done what we both need to do. Get each wheel on a balance machine and spin it. Look for runout (tire or wheel has side to side motion) or out of round (tire or wheel has high spots when turning). I have always used Micheline tires until this set of Bridgestones, but I also bought this car used, and the gal who owned it before apparently "felt" her way to the curbs a few times. There are marks on the bead of the wheels as a result. Alloy wheels bend very easily so I have a feeling my wheels are bent. They are so sensitive that if you do not torque them by hand (never impact gun) they will bend. It drives you crazy having the vibration, doesn't it!
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Wills 98 R AWD modded wagon 94 854 T some mods 92 740 wagon

Well I took the car to the tire dealer today and verified that 2 wheels are bent. They are slightly out of round, I guess the gal who owned the car before me hit a few potholes. The best part is I watched the tires spin on the balance machine, and it said they are balanced! The tire installers these days don't bother to actually LOOK at the wheel when it spins, I think he learned something today, so did I. Now it's time for 17" wheels.
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Wills 98 R AWD modded wagon 94 854 T some mods 92 740 wagon

1) The worst problem is that it has a bad vibration that seemed to be most noticeable in the frame or seat as opposed to the steering. At 60 -75mph it felt like the wheels would come off. I took it back to the dealer who then drove it and agreed to have the tires rebalanced. Went back one week later and it drives the same. The tires are new.

Is this a common problem? Could it be the brake rotors?

-without braking I assume? If so, it's not rotors and if the tires are properly balanced, then either there's a bent wheel (pothole damage) or one of those tires is out of round, bad cord, etc.

-If it's happening only while braking hard from higher speeds (typically), the rear rotors are likely to be warped (or rusty from sitting).

As for the other vibration, yes maybe a mount.

But, why bother questioning us here? Tell them you want it completely FIXED or you aren't buying it.

Ed,

I have made it clear to the dealer that I won't consider the car until the vibration is resolved and they seem willing to attempt to fix it. Since they are not a Volvo dealer (Acura) they don't have first hand knowledge of some of the C70 / Volvo quirks so I was trying to give them something to focus on to hopefully resolve the problem.

The vibration occurs at high speeds WITHOUT BRAKING. If it was a bent rim or out of round tire wouldn't that show up during balancing? They "claim" the tire were rebalanced.

Thanks,

Hawkeye

A bent wheel, bad tire can and will still be able to balance perfectly BUT yes, one paying attention and watching it spin (even on the car) should be able to see that.
They might end up subletting the work to a local Volvo dealer as that's what we see. Many other dealers bring us their used Volvos as their techs don't know anything about Volvos nor want to.
Unless you love THAT particular car, you "might" be far better off buying a Volvo certified used car from a Volvo dealer as it'll have an extended warranty. Warranty or not, you'll still want it checked out carefully as most of those cars are lease returns and those who lease do NO maintenance, many are in poor condition for a seemingly newer car. It's buyer beware IMO.

Ed,

Good advice...thanks!

Hawkeye

This car was hammered by the critics for front cowl (airdam) vibration at higher speeds. My indy tech recommends an S70 (or custom) airdam for drivers with this issue.

Shake when starting up and turning off could very well be related to the upper mount. It is *probably* not engine related. Shouldn't be, anyway. Nice engine, designed by Porsche.

Noise in steering may be the steering stops (just add grease) or swaybar endlinks (pretty cheap, even if fixed by a tech). Common to all 70's.
--
David \\ (98 S70 T5SE Black, misc mods (mostly lighting), red calipers) (92 940GLE)

If you mean to say that the C70 engine is built by Porsche, that is not correct. Volvo built this engine in coop with Tom Walkinshaw Racing (TWR), a British-based company.

Seems like cowl vibration would come from the front and be more noticeable in the front of the car. I did not detect any hood vibrations. The vibration I experieced seemed to be more in the underside or frame and you could feel it in the seat, almost as if it was coming from the rear. Would the cowl shake do that?

Thought I read somewhere on BB that brake rotors and pads could cause a similar problem. Have you heard of this?

I have read about the cowl shake problem in the convertibles but did not know it was also a problem in the coupe.

Thanks...Hawkeye

If it's convertibles only that have the problem, then I would suspect something in the suspension that can wear. You're feeling this while driving, not braking I assume? Things to check out are strut rod bushings, ball joints, CV joints, steering linkage, etc.

It's possible, I suppose, that it's a warped rotor, and it's easy enough and cheap enough to replace these yourself. If it's a rotor, I expect if you apply the brakes while at the high speed, the vibration would increase immediately (and diminish as speed diminishes). In this case, if you feel the vicration in the sterring wheel then the front brakes are the likely culprit.

--
David \\ (98 S70 T5SE Black, misc mods (mostly lighting), red calipers) (92 940GLE)

Cowl vibration doen't exist in C70 coupes but convertables, yes. I think David thought you were talking about the convertable which should be avoided at ALL costs.
The coupe is just like the S70 otherwise, besides the doors.

Hey Hawk,

2) Also noticed a shake when the car is first started and the same shake when it is turned off. Is this due to the upper motor mount being bad?

This annoyed me when I first got my car. After some homework found this
is quite normal for this engine.

3) During the first test drive I noticed some noise when turning left that seemed to come from the front. Did not notice it during the second test drive. Any ideas?

Probably the Steering stops. No biggy, just throw some grease on them every
4 months or so. Have the dealer show you where they are. It takes one minute
as you don't have to remove wheels or anything.

As far as problems check my c70 reply a few days back. I wrote down a few of them.

Note : I had my first battery failure [ away from home ofcourse ] in 25 years
of driving. If the battery is original in that 99 do yourself a big favor
and install a Megatron MT-47 ASAP.

Hope this helps some.

rd 99 c70 cpe