Boom boom boom but not basil brush

[Nordy]

Hi folks I'm new to this forum, so I would like to say hello and thanks for the tips I've read so far for fixing bits, mega help!
Does anyone know what the boom boom boom noise is that I can hear from the back of me motor at about 10mph,sounds like the kid next door whacking the bass drum it usually goes away when I turn up the radio but I've lost the code for that so I'm going to have to address the problem, it sounds like a wheel bearing but I had a good look and couldn't find any movement, should I try to grease it or am I barking up the wrong tree?

[oldskool73]

is it all the time or just over bumps? if only over bumps, worn suspension arms can sound like you're carrying a load of loose 2x4 in the boot.

[dghii]

A light sound, not really boomy could be a wheel bearing. Sounds are very tough to diagnose on the forum.

[911monty]

In what gear and RPM? Is the sound more noticeable when turning one way or the other? How are the CV joints on the drive axles? Boots torn?

[Frodo]

When my bearing went, I really couldn't feel any looseness when grabbing/tugging on the wheel. And I really couldn't hear anything unusual when I spun the unweighted wheel. But it did become more noticeable when turning. Mine, however, was a front wheel.

I let it go for a while, but it slowly became more noticeable. I still couldn't reproduce the laxity or noise with the car jacked up...I finally just went on the evidence I had (and a bit of faith in my diagnostic guesswork) that it sorta had to be the bearing. I replaced it. The noise was gone :dance:

[Filastein]

Originally Posted by oldskool73

is it all the time or just over bumps? if only over bumps, worn suspension arms can sound like you're carrying a load of loose 2x4 in the boot.

+1 Good analogy.

[Nordy]

Hi folks sorry for going to sleep on this after posting a new thread, this noise is getting louder, if you say boom boom boom in your deepest voice at the normal rate of speaking that's noise coming from the back of my 01 986 it's done about 60k one side has a new drive shaft that's the left side but the cv joints are okay on the other side and it's just had an mot, the sound is most noticeable at about 10mph accelerating or decelerating with clutch in or out, when turning or in a straight line, flat road or over bumps, I thought it might be the exhaust resonating at first but I can still here on acceleration until about 20mph when it fades away, I thought wheel bearing at first but it's not droning and I checked for movement on the freewheel, I was thinking of changing the transmission oil, then giving the remaining drive shaft a frowning at, or do you think I should start with the wheel bearing.

[That986]

Originally Posted by Nordy

Hi folks sorry for going to sleep on this after posting a new thread, this noise is getting louder, if you say boom boom boom in your deepest voice at the normal rate of speaking that's noise coming from the back of my 01 986 it's done about 60k one side has a new drive shaft that's the left side but the cv joints are okay on the other side and it's just had an mot, the sound is most noticeable at about 10mph accelerating or decelerating with clutch in or out, when turning or in a straight line, flat road or over bumps, I thought it might be the exhaust resonating at first but I can still here on acceleration until about 20mph when it fades away, I thought wheel bearing at first but it's not droning and I checked for movement on the freewheel, I was thinking of changing the transmission oil, then giving the remaining drive shaft a frowning at, or do you think I should start with the wheel bearing.

Does the frequency of the noise go up with speed? If not you could be looking at a CV joint but it does sound like a wheel bearing to me.

[algiorda]

Could be Motor or Transmission mounts are shot. See if there is any play in the engine/trans.

[Filastein]

Lots of ideas here but you might try a test. Remove one of the rear trailing link arms (not too hard a job) and see if the ball joint is so loose that it clicks when moved side to side.

This is pic of my front trailing arm but the rears were in the same state. The rubber boot is cut away but the joint moved with very little force. Symptoms were rattle and boom at low speeds.

[steved0x]

If it is a banging that happens more when accelerating, decelerating, or turning, my guess would be front engine mount. What Al said.

[Nordy]

Cheers fellas I will add these to the list

[Nordy]

Turned out to be the tyres, bit of a surprise they were old but not illegal, found out by accident I would never have associated the noise to the tyres, especially as I heard another boxster pass by making the same racket