Hum noise - Wheel bearing or "rubbing"?

condra

Hello guys.

My brother bought his first car there a few days ago. It's a 98 Mitsubishi Mirage. Nice little coupe for the price he paid.

Anyway, It came with 15" alloys (195/50/r15), but I think the standard is 14". They look great on the car and don't appear to be too close to the chassy, there's a couple of inches of space.

The first thing I noticed when driving it was a loud deep road noise. I initially put this down to the fact that the tyres are bigger and wider than my own.

The engine itself purrs very quietly.

But later, when driving on the motorway, I noticed the noise gets quite loud at speed, also the pitch of the noise gets higher, like when a kid puts a milk carton in his wheel. It seems to be coming from the back of the car.

My dad reckons it's a bearing problem, but I'm wondering if it might be a rub because of the non-standard wheels. The car seems to slow down very quickly at low speed too, at least compared to my own car.

Would it be worth my while jacking it up and turning the back wheels to see if there is a rub, or would it be the type of thing a mechanic needs to look at?

If it is a rub, would it be a simple case of putting some sort of spacer on the back wheels? He just put new tyres on the front and would hate to have to go down to 14" wheels.

Thanks for any thoughts on this.

peasant

If the tyre is rubbing it would certainly leave a mark that would be evident once you jack the wheels up and have a looksee

condra

Thanks for the quick response. I'll jack it up and have a goosey.

cadaliac

as you said, jack it up and have a look. It sounds like a bearing alright, but do not rule out the fact that it could be cheap tyres. The cheap tyres with their treads make an awful noise. Road noise that is.
See if the tyres are branded, if not, that could be your problem.

peasant

condra wrote: »

Thanks for the quick response. I'll jack it up and have a goosey.

don't forget to check the insides as well

condra

Hey just an update.

I checked the tyres and wheels and couldn't find anything. So today, I took it to Autoglass in Santry for a "free safety check".

I was expecting them to try to make a buck off me, but they guy said he couldn't find anything wrong. In fact, he said the shocks, tyres, brakes and bearings are all good.

So it looks like the road noise is from the "economy class" tyres on the back. The guy in Santry also said they would be quite loud.

I was also concerned that it has quite slow acceleration (compared to my Cynos, which is also a 1.3 auto), but I read up and it looks like the Mirage is just not a pokey car!

Thanks again for all the replys.

colm_mcm

try swapping the tyres front to back, any imbalance in the wheels or tyres should show up through steering wobble.