[PeteB]

It seems connected to road speed not engine speed and goes away under
acceleration. Is this probably an axle CV joint?
Braking changes it also but it only goes away on acceleration.

I'm about 25 miles from home and going to try to baby it home.

 

[Airforce1]

Open the hood and listen closely to the engine. If you do not hear anything have someone sit in the car and slowly bring up rpm to 2 or 3 grand. Might be the dreaded rod knock.How many miles are on your car? Whats the oil level like?

 

[PeteB]

Thanks for the tips.
It is related to road speed, and there is no abnormal sound when revving in neutral. I've had a rod bearing fail on an old Alfa so I know what it sounds like.
Made it home.

 

[avisitor]

I would jack up the wheel and check for play at 3 and 9
Also check for play at 12 and 6
Looking for ball joint play
Sometimes a pry bar may be needed to show excessive play

The other thing is it could be wheel bearings
Or CV axle

If there is no play and CV goes around without noise
And wheel bearings seem okay then road noise may be coming from the sway bar link

 

[camper]

maybe the brake caliper and pads noise. If you live in snow belt, the rust just kill the caliper piston and grab the pad too tight. Spray some water on the brake rotor, and see if there's any difference

 

[PeteB]

Thanks, I'll check these things in the morning.

 

[wd-50]

check for a bolt in the tire also

 

[PeteB]

Thanks, will do, it is a bit loud to be that but I will check.

 

[DarrenBach]

Does the sound change or stop when you turn? If it does then I would say CV joint.

 

[PeteB]

Turning hardly changes it at all, acceleration makes it go away.
I did the front pads about 4K miles ago and noticed that the driver's side
slide lower slide pin did not have a flat side and seemed to be much
tighter.
Is the factory front pad replacement manual online anywhere?

 

[kev510]

Sbb

Is the knocking sound correlate with road quality? More frequent over bumps perhaps?

 

[PeteB]

I've been working on cars on and off for over 40 years and in the old days would often put
a small dab of anti seize on lug nuts. I stopped when a friend said never do it. Early on
as a kid I tightened as much as possible without a torque wrench but have been torquing
for the last 40 years or so. I restored a 1958 Alfa Romeo including and engine swap, valve
job, installed upgraded cams and re-jetted the dual Weber carbs. I had a head gasket fail
on a Friday, ran out for a new gasket and had it installed by Saturday night. Pulled the
head with the carbs and exhaust manifolds in place.

Saw posts by a mechanical engineer on a Volvo forum who said using anti seize was the
right thing to do. I decided to try it on this car and used the torque wrench.

The wheel was loose, had about 1/16" play on the hub due to the lug nuts backing off.
Never again will I use anti seize. I have seen seasoned professional mechanics say
never use it as they've heard of wheels falling off.

I didn't even think to check the lug nuts when it first started but now I'm carrying the
torque wrench in the trunk and will check them all from time to time. I washed the lube
off with brake clean today.

The car is fine again.

 

[Airforce1]

I pit a little anti seize on all the lug nuts the first time any wheel comes off a vehicle.Never ever had a lug nut back out or even become loose. To have 5 of them come completely off and the wheel coming off is very unlucky I suppose.

Glad your issue is solved at no cost.

 

[DarrenBach]

The wheel was loose, had about 1/16" play on the hub due to the lug nuts backing off.
Never again will I use anti seize. I have seen seasoned professional mechanics say
never use it as they've heard of wheels falling off.

Pete, don't you think the alloy wheel played a part in this scenario? It's a lot different than the old, thin, stamped-steel wheel!
Not that I will use any anti-seize! :nerd:

 

[PeteB]

Pete, don't you think the alloy wheel played a part in this scenario? It's a lot different than the old, thin, stamped-steel wheel!
Not that I will use any anti-seize! :nerd:

Not sure but I won't be using any anti-seize again!
Part of the issue might be that I torqued the nuts in the summer at 90 deg
and temps dropped into the 20s. The wheel was fine for over 3K miles.