Exhaust Rattle?

[Griffyn]

I am not really sure what to do now. When my car is idling sometimes the exhuast seems to make a squeaky/rattling noise. But when I got it serviced in december there 'was nothing wrong' and just went down to the local ATS to see what they could do and again there is nothing wrong when there clearly is.

I cant see anything wrong myself, but the noise is from the back of the car and can only be heard at the back, at the front of the car it sounds fine. Anyone got any recommendations?

[vmail]

Put the gear into reverse and stick the handbrake on, as you gently release the clutch (not all the way) do you hear the same sound? I'm gonna take my car in on Monday. Also can you hear it if you car sitting in the drivers seat?

[Griffyn]

Its only when the car is idling, so when not pressing the gas pedal. So dont know if it will do that, and I can't hear the noise within the car, unless the window is open but I have to listen out for it to be honest. It doesn't affect me, its just annoying knowing that when I stop at traffic lights, etc people will hear my exhuast rattling away Well depends how loud my stereo is probably

[Bee]

Let's see if I have got this right: This noise which has been present for at least 3 months from last December is a soft squeaky or rattling noise. It is not constant, it only comes on occasionally when the car is idling, and only at engine idle speed; stepping on the accelerator makes the noise go away. It appears to come from the exhaust, and is best heard from the rear of the car, not heard at the front or inside the car. On inspection, you could find nothing wrong. The garage doing the car service found nothing in December, as did ATS recently.

Apart from loose fittings or components of the exhaust -- the most common cause of noise from this quarter, but this appears to have been ruled out, as examination on at least three separate occasions did not detect anything amiss -- the other possibility is a partially blocked catalytic converter due to broken or part molten honeycomb. The honeycomb material is fragile and can be easily fractured, or shattered through thermal shock (e.g. the normally very hot operating converter is drenched in driving through a flooded ditch). Or, alternatively, the material whose working temperature is 400º-800ºC can melt when it is subjected to an unduly high temperature of over 1000ºC (e.g. combustion of an abnormal composition/ratio of fuel, or misfire ). Another characteristic of this is a loss of power particularly noticable at high rev, when the engine appears to be capped where it shouldn't be. Have you found the engine refused to go higher than say 3000RPM, or any other evidence of bridled performance, for example, hesitancy on acceleration? Admittedly this would happen only when the blockage is quite severe.

"How do I know if my catalytic converter has failed?"

http://auto.howstuffworks.com/question482.htm

This is just my educated guess, and a humble opinion.

--

Bee.

[Griffyn]

Thanks for the idea but the engine revs pretty much as it always has, except when obviously brand new. The performance is the same as always....too slow So guessing it won't be a blocked cat. Plus when at the side of the car the noise seems to come from the rear, so if it was a cat problem then im guessing the noise would be futher forward and it would have failed the MOT if it wasn't working properly?

I also have a chrome tail pipe on the end of my exhaust.....but the 'screws' aren't loose for this, and it never used to rattle so can't see that being the cause.

Bee you got that all right, but the exhaust started making this noise around september time last year I guess, but its not something easily heard as I usually have the engine off when out of the car so can't say when it definitely started.

Quite confused and not sure what to do :( Although I am thinking of changing my car september time, so may just leave it, but I dont know if I will actually change my car though.

[vmail]

you can also hear it. As swich off from the key and keep you foot down on the gas

you can also hear it when driving, during gear change. take the car out of gear and tap on the gas

[Ryan1985]

I had the same thing, my mate's a Toyota mechanic and he told me how to fix it but I never did and it just went away itself! I'll ask him what the fix is though and I'll reply back in here later on!

[vmail]

There is a gargling noice noticable when driving in 2nd gear with revs around 2500RPM

[Ryan1985]

From an msn convo with my mechanic mate Griffyn:

xxxxxx says:

Spray grease or wd40 on the bolts at your back box and manifold, they have springs on them

xxxxxx says:

and the exhaust rubbers do them aswell

xxxxxx says:

there wil be 2 at the rear axle and 2 under the front after the manifold

Hope that helps!

[blue-baby]

From an msn convo with my mechanic mate Griffyn:

xxxxxx says:

Spray grease or wd40 on the bolts at your back box and manifold, they have springs on them

xxxxxx says:

and the exhaust rubbers do them aswell

xxxxxx says:

there wil be 2 at the rear axle and 2 under the front after the manifold

Hope that helps!

:!Removed!:

[Ryan1985]

Cheers Heather! :P

[Bee]

...Spray grease or wd40 on the bolts at your back box and manifold, they have springs on them

and the exhaust rubbers do them aswell

there wil be 2 at the rear axle and 2 under the front after the manifold...

So a dose of grease/lubricant on the correctly but loosely fitted attachments, naturally missed and undetectable on mere visual inspection, is the answer to resolving the mystery. Presumably the noise is believed to come from the loose pieces knocking against one another at certain frequencies, which happen to be the ones prevalent during engine idling, and may also be present at other times. I must remember that. Thanks, Ryan1985.

--

Bee.

[blue-baby]

There not loosley fitted, there on springs so the whole exhaust can flex with engine movment. Like anything on a car they corrode and start to creak.Only a suggestion,might not be the actual cure but they are common faults.

[Griffyn]

Cheers Ryan & his mystery friend does sound like it could help. If I get round to it at the weekend may jack it up and spray some WD40 in the places noted. I know where you mean as I have seen the springs before. Just a pain as I need to get some wood to put under the wheels so I can jack it up (as my jack's dont fit under the car now it has been lowered).

Also found something really weird when I just got back from work, if turn the lights off the sound stops for like half a second.....turn the lights on and no difference. Now I really dont get why turning the lights off would have an effect on the exhuast :S

[vmail]

The rattle is no more after I stole Bee's wording

check for noise, lubed belts,noise hasnt occured

I dont think I want to keep the car, the last two years I have had to take the car back in to get the sump leak repaired

sump leaking, stripped, cleaned, resealed

When I asked why this was the third time it needed to be done, I was told that they did not put enough sealent on before, but now they have and it will be guaranteed for 12 months, however on the back of the invoice it says 3 months.

and theres more, makes me wish I never got a toyota. The invoice

XMSC02 SCREENWASH 250ML £1.99

I did what other TOCer suggested and it was topped up on Sunday, I was told that the engineers used some of the fuild to test the wipers, so it needed replacing.

and this one makes me laugh

T17801-23030 AIR FILTER £11.78

On Sunday I had a K&N Air Filter, today I have a K&N Air Filter (same one), surely this is illegal

oh and 'the oil has been drained' the oil is cleaned than Sunday but not that cleaner.

[Bee]

...if turn the lights off the sound stops for like half a second.....turn the lights on and no difference. Now I really dont get why turning the lights off would have an effect on the exhuast

Now then, this sounds more like it is from the fuel pump! The noise coincides with the on and off of switching the electric, and it is from the rear of the car. Can you positively identify the source of this noise? When the ignition is switched on, listen for the sound of the electric pump motor running. It can be more easily audible if the rear seats are lifted. Is this the same noise?

--

Bee.

[Bee]

...last two years I have had to take the car back in to get the sump leak repaired [the third time]

...sump leaking, stripped, cleaned, resealed

...I was told that they did not put enough sealent on before...

XMSC02 SCREENWASH 250ML £1.99

...the engineers used some of the fuild to test the wipers...

T17801-23030 AIR FILTER £11.78

On Sunday I had a K&N Air Filter, today I have a K&N Air Filter (same one), surely this is illegal

'the oil has been drained' the oil is cleaned than Sunday but not that cleaner.

Clearly these are a bunch of crooks!

Write to the owner of the garage to complain in the strongest term, and never to go back again. Report to the Trading Standard Institute when the unhappy saga comes to some sort of conclusion. You want them to chronicle this episode for they would keep a record in case of any, this and future, prosecution. And, if you had used your credit card for payment, report that to the credit card issuing company as well.

--

Bee.

[vmail]

There was one thing that they did not charge me, there was a 75ml of Protective Lubricant, at the bottom it says

'Part of this product may have been used on your vehicle. If so, please accept the remainder for your home use.'

Well its not bad as last year I was told that they put petrol additive in the (empty) fuel tank, when I got the car the performance wasnt that good. After a ten hour drive (Hull-Southampton-Hull) the engine and power cut out on the M62 third lane at 2AM. Most of the M62 has no street lights, even when I was being towed I could not start the car. As soon as I got off the motorway the dash light came back on and I could start the car. The fault was the earth connection was lose, I didnt losen it

I think crooks is too polite

[Griffyn]

Its definitely not the fuel pump as it doesn't seem to make any noise apart from pumping fuel when listened to from above with the seats up and the matting out the way.

Also doesn't seem to make the noise when 1st turned on, as at work today before I left I turned it on and it didnt make that noise and when I got back home it was making the noise.

I will just have to jack it up at the weekend and put it on my axle stands and see if can figure out what is going on. But quite strange.

[SephirotH]

Hi Everyone,

I have the same problem the exhaust is rattling and i can hear from inside the vehicle. :o

This happens when the engine is idle. If i press on the gas the rattle goes. I dont know the revs exactly coz i have a digital display and they dont show.

Thanks,

Seph

[Bee]

...the exhaust is rattling and i can hear from inside the vehicle...happens when the engine is idle. If i press on the gas the rattle goes...

A warm welcome. Seph.

Have you tried the grease/WD40 spray trick as suggested earlier?

--

Bee.

[SephirotH]

Hi Bee,

I didn't have time to try that but the strange thing there was no rattling today.

Hope it won't come back

Seph

[venomx]

On 3/24/2006 at 5:04 PM, vmail said:

Put the gear into reverse and stick the handbrake on, as you gently release the clutch (not all the way) do you hear the same sound? I'm gonna take my car in on Monday. Also can you hear it if you car sitting in the drivers seat?

This is what happens to me too. Maybe its a common fault ?

[wildtapholer]

It was a 15yr old post.