Noise From Underneath,help!

[Guest arfacobra!!]

Hi All,

I have done a search already on this(rollbar links etc)but my noise seems different.

Wreg 1.9 mk2

Noticed it for the first time couple of days ago,going over speed humps under 10mph I get a deep thump from underneath you can feel it in the drivers seat but its maybe 1/2 a second after going over.

Then I noticed it happens if you pull forward a couple of feet and stop again with 1/2 second delay.

the best way I can describe the feeling/noise is if you had something heavy in the fuel tank which rolls forward when you stop.after the car is level

 

Thanks in advance

steve

[NikpV]

Sheared engine bolt/mounting ?? engine/gearbox rocks back when not under load to give the thump??? There is one that commonly shears - think its a gearbox retaining bolt.

[katman]

Sheared engine bolt/mounting ?? engine/gearbox rocks back when not under load to give the thump??? There is one that commonly shears - think its a gearbox retaining bolt.

I'd go along with that having suffered the same problem last month :angry:

[Masked Marauder]

You can get a thump from the fuel tank if you have about 2/3 a tank of fuel.

[Guest galaxykid]

Roll restrictor is the correct name for the offending item :angry: most common part that fails is the bolt at the gear box end as mentioned earlier :D its an easy repair and is a DIY job if you have means to access the underneath of the car safely? ramps in your driveway may not be an option due the need to accellorate up them while the engine slams about under the bonnet :lol:

also this extra movement can fracture some of the alloy AC pipes so be careful :angry:

also agree with the masked maruaders post on fuel sloshing! can be rather scary sound/feeling at times if your not ready for it! :D

[Guest arfacobra!!]

Hi,

thanks for the replies,

The first thing I thought of was fuel sloshing about it is a like that,but I have driven a lot of cars including a fire engine(I am a fireman! oops! firefighter!)

It just seems to solid a sound/feeling to be that,and there seems to be only one thump never a second

The engine mount sounds interesting can anyone give a location

I have only had the car 3 weeks bought from ford dealer with warranty,not too impressed so far.It also has lost power which has returned.reading your threads it points to the maf

thanks

steve

[NikpV]

Roll restrictor

 

thank-you I've been trying to remember the name since I saw the OP. Somewhere on here I've seen a photo of this - perhaps do a search.

[Guest arfacobra!!]

Hi All

I have had a look over the weekend and it does seem to be something to do with the tank!I was on 3/4 of a tank.Got someone else to drive forward while I had my hand on tank,felt the thump followed by 2 weaker ones.

Still thought this cannot be right.went into ford dealer today they agree it should not do that.possibly something has come detached inside(baffle plate)

So I am going to get onto the dealer I got it from,only 3 weeks ago!!

On the loss of power(MAF?) the dealer today said unless the engine management light came on at the time the computer will not register a fault and if its running OK now they would not be able to find a fault and would charge even with the warranty

thanks

Steve

[Rallim]

On the loss of power(MAF?) the dealer today said unless the engine management light came on at the time the computer will not register a fault and if its running OK now they would not be able to find a fault and would charge even with the warranty

I would question the engine management light thing, I'm sure you can have faults logged but not light any warning bulbs?

 

I had power loss problems on my TDI which were releated to initially the MAF and in the end a replacement turbo, but in all that time I had no 'engine management' light. When the power loss occurred it would clear by turning the ignition on and off.

 

I would go and talk to the dealers again, as the power loss issue is a direct safety problem and should not be ignored... ie pulling out at a busy junction and all of a suddent the power dies, not pleasant.

 

 

Gordon.

[Topbloke]

unless the maf go's open circuit its very unlikly that a code will be stored, i have diagnosed loads of these via vag com or the vauxhall equivalent and none actually store codes, the techies should expect to see a fluctuation in readings as the car is reved .as far as the tank is concerned there is a swirl chamber to retain fuel in while cornering etc but no baffles as such a good test would be to see if it does it when there is more/ less fuel, but as its under warranty let them deal with it but i still recon that it will be the bar as mentioned above

[Guest arfacobra!!]

Hi

Thanks for that,I will take a look underneath.Just waiting for the dealer to get back to me

Now I am on 1/2 tank it does not seem as strong

Will let you know what happens

cheers

Steve

[Masked Marauder]

I agree that there is no baffle in the tank, it is a one-piece blow-moulded plastic affair. Everyone's thumps with a 1/4 tank of fuel, that is why we knew straight away thats what it was.

 

As for the fault codes, an errant reading from a sensor may not generate a fault code if the sensor is still operating within the minimum and maximum readings acceptable to the ECU. But that does not mean it is giving the correct reading at the correct time....

[Guest arfacobra!!]

Hi All,

I have finally got the car sorted.

The dealer removed the tank checked(found no fault) and refitted it, result, still the same!.

Took it out again and replaced it with a new one,result, almost total silence,if I was being picky you can just about detect the slightest noise.

Opinion seems to be that although the tanks appeared the same maybe later tanks have been modified.Mine is a very early mk2

Maf was also replaced,alarm sensors replaced and the noise from the handbrake turned out to a missing part from around the button!

So I am a lot happier with the car now

So for all those out there suffering with noisy fuel tanks maybe there"s hope

 

Cheers

Steve