I should probably stick with the obvious and get my tires replaced, but wanted some second opinions.

Have 4 year old Contis with about 1/8" until they hit the tread wear indicator. They've been very noisy since I got the car, and get very slippy in the rain, but wanted to try and get to the end of the year on them before replacing. Had a bad vibration back in February, got them balanced and have been good since then.

A couple of weeks ago I got on the highway for a few miles and the car had horrible vibrations through the steering wheel. Then on the return trip, was smooth as usual (assumed I had a flat spot or something which smoothed back out). I usually don't drive on the highway to go to work, so was surprised when I started to feel the steering wheel shaking on my commute at 45-50 mph. I rotated the tires front-back, which only marginally improved things. That really surprised me, because I figured if it was an out of balance or a bent rim it would move to the back of the car.

Nothing looked out of the ordinary with the tires that I can see, except the 2 on the passenger side both have minor dry-rot sidewall cracks, while the driver side tires look like new.

So anyway, took a 500 mile trip this weekend. Horrible ride. But the odd thing was that sometimes the ride would smooth out. I'd be going around 70-75, and then it would be perfectly smooth for a few miles, but the vibe would always come back. Also, what concerns me slightly is that it rides/handles like the tires are over inflated (too hard and too drifty on the highway). Bumps and impacts are soft as ever so not thinking it's a shock/spring issue.

Does it sound like a tire cord let loose, or just have reached the point where they're old and hard? I've never experienced that happening so suddenly the way this has. It feels like a tire is out of balance, so I'm leaning toward going with the obvious diagnosis.

Thanks,
-Michael

 

have you checked tire pressure? at highway speeds, tires get hotter and the pressure will increase. Alloy wheels are tough to bend, but they can crack. Other than that, if the tires are close to replacement its not worth spending the money to rebalance then. I am curious as to what size tires you have. I have 20 inch Sepangs and Toyos on the XJR, which ride and perform well, but they are noisy

RyeJag

 

Oh yes, I adjusted all pressures after rotating. 30 front, 32 rear.

I'm glad to know that these rims won't "bend" per say. It hadn't gone through any humongous pothole and then got the bad vibration, haven't curbed them or anything. It was just normal one day, horrible ride the next.

I have the 18" 15-spoke. I had test driven an XJ with 19" 5-spoke... I thought that car had a horrible ride, felt every grain of sand in the road. The 18" is much more compliant. This is the 2nd set of tires on this car, the PO put on an identical set of the OE Contis in 2008 (per tire date code). I knew it would need new ones soon.

I agree with you, even $40 would be better spent towards the new tires rather than trying to get 2 more months out of these old ones. As I mentioned, they're awful in the wet. I was going around an on-ramp at 35 mph in the rain--driving gently--and the back end kicked out and traction control had to step in.

 

How even is the tire tread across tire. Is the tread scalloped, bumpy, or uneven? Most likely your tires are the cause of what you're feeling, but when you replace them you should have the rest of the suspension inspected. Often worn or loose steering parts are the cause of what made your tires start to vibrate. Have your inner and outer tie-rods and your upper and lower ball joints inspected at least.

 

I always kept mine at the factory pressures, but no idea what the last 4 years saw on these. The tread is worn in the center more than the sides, which suggests over inflation. Tread wear is otherwise fine, doesn't look like any issues with alignment.

I will definitely check on the suspension again, I had a look myself recently when I did the brakes.

 

Might want to also check the front bushings for wear...

 

Check the wheel nuts as well

Cheers
34by151

 

I've had Contis on a BMW that, as they got to near the end of their live, the belts started to separate causing the tires to go out of round and vibrate similar to yours. A balancer should find this but probably not worth the bother with your tires near worn out.

Stu

 

This is exactly what I think is happening... I'm going to just go ahead and get a new set in the next few weeks.

I know my rear bushings are on the to-do list, they're just now starting to clunk on certain bumps, front still seems nice and quiet. Will take a look at all of them.

 

How long ago was that?

Are the caliper pistons and guide pins in good shape?

Right after you get a pulsing event, pull over and feel the wheels. If one caliper is sticking the wheel will be substantially hotter than the others.

 

I bought my XJ8 X350 a month ago when I left the sellers house I decided to pump the tyres up as I was planning to drive it home about 3000 k,s

When I looked at the tyres while pumping them up they looked right on the wear indicators

I thought they should get me home as soon as I got it on the highway I new it needed tyres the thing was all over the road and tyre shake driving the first 1000 k,s I started to panic praying it wouldn't rain got to Melbourne while on the way I rang a couple tyre guys got a price arrived that evening next morning just went and had them all replaced what a difference

I then felt safe driving the remaining 2000 k,s home soon as I got home took it for a specialist wheel alignment car is perfect as for brand they are some Chinese brand sizes are Front 245/35/19
Rear 275/30/19

I just thought these will do till I get home

I am very happy with them quiet smooth and price was unbeatable

I haven't driven it in the rain yet that will be the test

I have Kuhmo,s on my XJR6 very happy with those

 

Sounds exactly like mine. They're about 1/8" from the wear indicators right now.

What Kuhmos did you get? I was planning on going with another set of ContiProContact, but looks like they're starting to discontinue that tire in the size for my car I want quiet and smooth--I know the Contis are very quiet when new, friend has a new Ford with them from the factory and it's silent.

No problem with the brakes... stops smooth as ever. Just this running vibration when driving over 45 mph.

 

For the X350 I bought some Chinese tyres needed them there and then
China tire,China tyre,bias tyre,nylon tyre,uhp tyr

I was 2000 k,s from home I thought they will do if I don't like em on the way home Ill buy new ones when I get home

I like them smooth quiet pretty grippy but I do live in a subtropical environment so wouldn't know what they are like in cold climates but very happy and $550 for a set front and back fitted and balanced I will buy them again for that price

 

Dry rot sidewall cracks are seriousky bad news. You can have a blowout without provoking thrue e.g. potholes. That could kill you and / or somebody else. Believe me, a blowout at speed is scary! Replace all four now.

 

Certainly not as cheap, but ive tracked the same model with the conticontact whatever the heck they call em and pirelli pzero neros......

No comparison....pirellis are quieter, smoother and stickier....

The quitest and smoothest ive found are michelin hx mxm2......but traction suffers, especially in wet

 

Looking at the survey results on Tire Racks website is a good way to pick tires

Here is some info on Grand Touring All-Season tires ....

http://www.tirerack.com/tires/survey....jsp?type=GTAS


Other tires types are here .....

http://www.tirerack.com/tires/surveyresults/index.jsp

.

 

The P-zero is quieter and smoother than the Conti? They're also cheaper at Discount Tire... $120 cheaper for the set of 4 is not insignificant. I figured at the lower price they would not be as good.

 

I love the pzero....
I drove an xf with conticontacts and one with pzeros on track and off recently...the pzero was superior all around IMO......

The pzero nero is what they put on the new XJ as well

If you really want some stickiness, the pzero rosso rocks


All that said, the mxm4 is ridiculously smooth and quiet.....I just wouldnt recommend them if you drive 'spiritedly' even on occasion.

 

I believe the Conticontacts is a touring tire and the Pzero is a Performance All-Season tire

If you want a Performance All-Season tire that is also smooth and quiet check out the Continental DWS reviews and its price point

http://www.tirerack.com/tires/survey...jsp?type=UHPAS

.

 

Any experience with Toyo Proxes 4. They handle well and run smooth, but are noisy. They came with the car, but I am looking for another tire when replacement time comes. Kumho Escta appear to offer good performance at a reasonable price.
RyeJag