MG4 Rumbling and vibration

[tsedge]

I get a little bit of that too.
But I am rightly or wrongly assuming it's tyre flat spots with being sat on a boat for 8 weeks.
Happens to a lot of cars and should sort itself out if it is that

That is likely but it still needs confirming if this is the cause. Someone needs to take the plunge with new tyres or a tyre check.

 

[tsedge]

If the car was faultless I’d have all-weather tyres on it by now.
It would be ironic and great if fitting new tyres sorted it, but I’m not willing to spend £500 to see.

It is most likely the tyres, especially if you feel it throughout the car and just gets worse as speed increases. There are not many things that would behave like that.

Unlikely to be drivetrain as it is RWD and felt through the steering wheel. Cooling pump wouldn’t be felt throughout the car either.

 

[Deleted member 9692]

Cooling pump wouldn’t be felt throughout the car either

Beg to differ on that. After hard acceleration I feel a rumbling through the car. For example, travelling at 30 mph, no rumble. Then accelerate hard to 70mph, rumble starts. Maintain speed at 70mph and after a few seconds, the rumble stops. I have had it looked at and service have diagnosed it as the cooling pump for battery. That’s exactly what it feels like to me and you can feel when it switches off. I‘ve driven their demonstrator for comparison and exactly the same behaviour.

 

[tsedge]

Beg to differ on that. After hard acceleration I feel a rumbling through the car. For example, travelling at 30 mph, no rumble. Then accelerate hard to 70mph, rumble starts. Maintain speed at 70mph and after a few seconds, the rumble stops. I have had it looked at and service have diagnosed it as the cooling pump for battery. That’s exactly what it feels like to me and you can feel when it switches off. I‘ve driven their demonstrator for comparison and exactly the same behaviour.

Ok… but it stops when it switches off right, not a continuous rumble?

Edit: and it doesn’t get stronger with speed, right?

 

[Ian Key]

Continental Tyres has an explanation of flat spots here

 

[Deleted member 9692]

Ok… but it stops when it switches off right, not a continuous rumble?

Correct

 

[tsedge]

Correct

And it doesn’t get stronger with speed, right?

 

[tsedge]

Continental Tyres has an explanation of flat spots here

We might have a case of semi-permanent flat spotting

 

[Deleted member 9692]

And it doesn’t get stronger with speed, right?

It’s constant. My point was that you said cooling pump wouldn’t be felt through the car, mine definitely is. Fortunately it seems to be lessening with time, it’s not tyres though (for me, may well be for others)

 

[tsedge]

It’s constant. My point was that you said cooling pump wouldn’t be felt through the car, mine definitely is. Fortunately it seems to be lessening with time, it’s not tyres though (for me, may well be for others)

Agreed, I was clearly wrong about that.

My point is I am hearing about a continuous rumble that gets worse with speed, which doesn’t sound like the pump.

 

[Deleted member 9692]

Agreed, I was clearly wrong about that.

My point is I am hearing about a continuous rumble that gets worse with speed, which doesn’t sound like the pump.

I wasn’t trying to pedantic by the way, I guess some on this thread it will be tyre problems but being as I’ve felt “rumbling and vibration” with two Trophy’s I’ve driven I thought worth sticking my oar in obviously if it gets worse with speed not what I am experiencing

 

[Vipar]

My Motorhome used to be parked for months on end. But after about 10 miles the flat spots vanished. So I doubt that is the problem.

Check this out on the Motorhome fun forum

 

[bowfer]

Im not convinced it’s flat spots, unless continentals are bad for it.
Im at 300 miles and no sign of it going away.
I’ll be delighted if it is that simple though, and will get the all-seasons ordered quickly after someone confirms it.

 

[bowfer]

It is most likely the tyres, especially if you feel it throughout the car and just gets worse as speed increases. There are not many things that would behave like that.

Unlikely to be drivetrain as it is RWD and felt through the steering wheel. Cooling pump wouldn’t be felt throughout the car either.

Badly machined drive shafts could cause it, as could any transmission imbalance.
The fact it is felt through the steering does suggest a front end issue of course, but possible rear end vibration is travelling through the car?

 

[siteguru]

Have you check the bolts on the rear undertray? Are they secure? (Just in case it is vibrating and causing the feeling).

 

[Hallix73]

Mine defo gets worse with higher speed. My first thoughts are the undertray bulge causing the vibration. However would that be felt through the steering wheel? Could be tracking I need to check tyre wear tomorrow before goes back on Friday.

 

[bowfer]

Have you check the bolts on the rear undertray? Are they secure? (Just in case it is vibrating and causing the feeling).

The rear undertray on my car is soaked in oil, I’m going nowhere near it.
Be interesting if the breather fix on 29/11 gets rid of the vibration, assuming they tighten it properly.
The rumble definitely comes from the front though, really doesn’t sound like a ‘flapping’ noise from the back.
And would that cause steering vibration?

 

[bowfer]

Mine defo gets worse with higher speed. My first thoughts are the undertray bulge causing the vibration. However would that be felt through the steering wheel? Could be tracking I need to check tyre wear tomorrow before goes back on Friday.

How many miles have you done?
Would bad tracking show as tyre wear yet?

 

[Hallix73]

How many miles have you done?
Would bad tracking show as tyre wear yet?

800 miles so far. Maybe?

 

[bowfer]

This is a superb thread, guys.
Im really enjoying bouncing ideas off each other, we have more ideas than the dealers!
Prize for whoever guesses right?